Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
> Yes, just for no other reason than to make sure the ribbon in the connector > was making good contact. OK, just making sure I understood. >Look below: I never understood if my logic probe results on the CS pins were >correct. I will have to double check that on the computer and let you know. If it is continuously writing to the screen you should see them toggle. >as I was writing this just now I moved the M100 in front of me on the >desk, >hit CTRL and BREAK and it is flawless again. >So fair to say not the ribbon? This sounds like a classic bad connection. It could be the ribbon connector a bad solder joint on the main board connector or screen, etc. These can be hard to find. >Also, T21 looked a little twisted T21 is part of the main power supply switching circuit. If it did not work you would have no power at all. As long as you measure -5, +5 you are OK > I'm wondering if its capacitors C47 or C54 - a hunch. C64 is part of the modem circuit so probably not an issue for this problem. It looks like C47 is in that area as well based on schematic. Intermittent problems are tough. I have spent months tracking them down before as they have a habit of never occurring when you are looking for them. Good luck Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Tuesday, July 28, 2020 10:43 PM To: m...@bitchin100.com Subject: Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search Yes, just for no other reason than to make sure the ribbon in the connector was making good contact. Look below: I never understood if my logic probe results on the CS pins were correct. I also tested a few other components with my multi-meter. All were okay. Then I reassembled, fired up and no result. Then, why I don't know, I turned unit on while holding down just CTRL and BREAK (No reset) and it worked for two days! I ran a burn in test. Just a full line of text that scrolled and looped. Ran it overnight once. Flawless. Dumb luck (likely)? What is happening when I hold just CTRL and BREAK and turn on? Some variation of an initialization? I know cold/hard reset is CTRL, BREAK, RESET and turn on. What the!?! After trying all sorts of reset combinations today to no result, as I was writing this just now I moved the M100 in front of me on the desk, hit CTRL and BREAK and it is flawless again. I'm running the loop. So fair to say not the ribbon? I think I have an intermittent issue with a component due to heat or power on. A guess. In randomly ready about the LCD and looking at service manual, I'm wondering if its capacitors C47 or C54 - a hunch. Also, T21 looked a little twisted after I replaced the internal battery and I noticed it was REALLY hot. To hot to touch with your finger. After straightening it some, it ran cool. Is that T21 failing after heating up? I assume T=transitor. I'm close! If I only knew what I was doing!
Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
Yes, just for no other reason than to make sure the ribbon in the connector was making good contact. Look below: I never understood if my logic probe results on the CS pins were correct. I also tested a few other components with my multi-meter. All were okay. Then I reassembled, fired up and no result. Then, why I don't know, I turned unit on while holding down just CTRL and BREAK (No reset) and it worked for two days! I ran a burn in test. Just a full line of text that scrolled and looped. Ran it overnight once. Flawless. Dumb luck (likely)? What is happening when I hold just CTRL and BREAK and turn on? Some variation of an initialization? I know cold/hard reset is CTRL, BREAK, RESET and turn on. What the!?! After trying all sorts of reset combinations today to no result, as I was writing this just now I moved the M100 in front of me on the desk, hit CTRL and BREAK and it is flawless again. I'm running the loop. So fair to say not the ribbon? I think I have an intermittent issue with a component due to heat or power on. A guess. In randomly ready about the LCD and looking at service manual, I'm wondering if its capacitors C47 or C54 - a hunch. Also, T21 looked a little twisted after I replaced the internal battery and I noticed it was REALLY hot. To hot to touch with your finger. After straightening it some, it ran cool. Is that T21 failing after heating up? I assume T=transitor. I'm close! If I only knew what I was doing! On Tuesday, July 28, 2020, 06:10:24 PM EDT, Jeffrey Birt wrote: You squeezed the end of the ribbon cable that plugs into the main board? Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Tuesday, July 28, 2020 2:45 PM To: m...@bitchin100.com Subject: Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search :( Short lived. Worked for 2-day. Back to old glitch. On Sunday, July 26, 2020, 06:26:04 PM EDT, Jeffrey Birt wrote: Excellent! Let us know! Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 5:19 PM To: m...@bitchin100.com Subject: Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search Working but "uncle" LOL. After logic prob test, I got some pliers and gently squeezed the LCD connector to ensure good contact with the clip and wires before reinstalling. Fired it up. Nothing. Blank screen. Warm boot, nothing. Hard rest, LCD pixels went dark momentarily. Then nothing. About to call it quits but something told me to switch off, hold just CTRL and BREAK while turning on (no reset button). It fired up perfect, all lines. Who knows? We'll see if it sticks before installing REXCPM. On Sunday, July 26, 2020, 05:42:36 PM EDT, Chris Fezzler wrote: For what it is worth, logic probe results for LCD connector chip select pins: CS01 (pin 18) = H CS20 (pin 14) = H CS21 (pin 12) = H CS22 (pin 10) = H CS23 (pin 8) = H CS24 (pin 7) = H CS25 (pin 16) = L CS26 (pin 15) = L CS27 (pin 13) = L CS28 (pin 11) = L CS29 (pin 9) = L I took the prob positive from C83 and ground from C8. On Sunday, July 26, 2020, 03:55:00 PM EDT, Chris Fezzler wrote: No after market ROM. Logically, I would think the fact that the top four lines are perfect, the hard reset produces a perfect Menu screen, and just the bottom four lines are garbled would be a clue where to look. I know nothing other than reading a lot off Internet. My instinct tells me the issue is a component that regulates power or signals to the LCD driver chips for the bottom half of the screen. The are getting power (because we see gibberish and the perfect Menu screen) but perhaps it is the wrong voltage or intermittent power or signal. Thoughts are: Capacitors C47 or C54 and or M17 and/or M25. But I don't know how to determine their impact on the issue. On Sunday, July 26, 2020, 11:25:01 AM EDT, Jeffrey Birt wrote: When comparing your two pictures, after rotating them right side up, I noticed just now that not only do you have blank blocks but some of the characters are reversed. That is really bizarre. I’m not sure if that points to a problem with how the LCD drivers are being configured/initialized or what data is being sent to them. If the driver ships are outputting a built-in font here it might be a chip configuration issue. If the display is always bit mapped, then it would be something else. Do you have any sort of aftermarket ROM installed? Very interesting problem. Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 9:47 AM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search Gladly. On Sunday, July 26, 2020, 08:36:06 AM EDT, Jeffrey Birt wrote: Can you attach a picture of the cold boot screen too? The positive and negative clips go to a +5 and gr
Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
John - I'm going back in LOL. On Tuesday, July 28, 2020, 04:11:18 PM EDT, John R. Hogerhuis wrote: On Tue, Jul 28, 2020 at 12:45 PM Chris Fezzler wrote: :( Short lived. Worked for 2-day. Back to old glitch. Still, almost certainly the problem is at the connector then if tightening fixed it up for a time -- John.
Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
You squeezed the end of the ribbon cable that plugs into the main board? Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Tuesday, July 28, 2020 2:45 PM To: m...@bitchin100.com Subject: Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search :( Short lived. Worked for 2-day. Back to old glitch. On Sunday, July 26, 2020, 06:26:04 PM EDT, Jeffrey Birt mailto:bir...@soigeneris.com> > wrote: Excellent! Let us know! Jeff Birt From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 5:19 PM To: m...@bitchin100.com <mailto:m...@bitchin100.com> Subject: Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search Working but "uncle" LOL. After logic prob test, I got some pliers and gently squeezed the LCD connector to ensure good contact with the clip and wires before reinstalling. Fired it up. Nothing. Blank screen. Warm boot, nothing. Hard rest, LCD pixels went dark momentarily. Then nothing. About to call it quits but something told me to switch off, hold just CTRL and BREAK while turning on (no reset button). It fired up perfect, all lines. Who knows? We'll see if it sticks before installing REXCPM. On Sunday, July 26, 2020, 05:42:36 PM EDT, Chris Fezzler mailto:fezz...@yahoo.com> > wrote: For what it is worth, logic probe results for LCD connector chip select pins: CS01 (pin 18) = H CS20 (pin 14) = H CS21 (pin 12) = H CS22 (pin 10) = H CS23 (pin 8) = H CS24 (pin 7) = H CS25 (pin 16) = L CS26 (pin 15) = L CS27 (pin 13) = L CS28 (pin 11) = L CS29 (pin 9) = L I took the prob positive from C83 and ground from C8. On Sunday, July 26, 2020, 03:55:00 PM EDT, Chris Fezzler mailto:fezz...@yahoo.com> > wrote: No after market ROM. Logically, I would think the fact that the top four lines are perfect, the hard reset produces a perfect Menu screen, and just the bottom four lines are garbled would be a clue where to look. I know nothing other than reading a lot off Internet. My instinct tells me the issue is a component that regulates power or signals to the LCD driver chips for the bottom half of the screen. The are getting power (because we see gibberish and the perfect Menu screen) but perhaps it is the wrong voltage or intermittent power or signal. Thoughts are: Capacitors C47 or C54 and or M17 and/or M25. But I don't know how to determine their impact on the issue. On Sunday, July 26, 2020, 11:25:01 AM EDT, Jeffrey Birt mailto:bir...@soigeneris.com> > wrote: When comparing your two pictures, after rotating them right side up, I noticed just now that not only do you have blank blocks but some of the characters are reversed. That is really bizarre. I’m not sure if that points to a problem with how the LCD drivers are being configured/initialized or what data is being sent to them. If the driver ships are outputting a built-in font here it might be a chip configuration issue. If the display is always bit mapped, then it would be something else. Do you have any sort of aftermarket ROM installed? Very interesting problem. Jeff Birt From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 9:47 AM To: m...@bitchin100.com <mailto:m...@bitchin100.com> Subject: Re: [M100] Listserv Search Gladly. On Sunday, July 26, 2020, 08:36:06 AM EDT, Jeffrey Birt mailto:bir...@soigeneris.com> > wrote: Can you attach a picture of the cold boot screen too? The positive and negative clips go to a +5 and ground source on the M100 PCB itself. The PPS setting if ‘Pulses Per Second’ when using it as a logic pulser, i.e. to inject a pulsing signal. On the chip select lines you should she them quickly toggling. Jeff Birt From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Chris Fezzler Sent: Saturday, July 25, 2020 6:20 PM To: m...@bitchin100.com <mailto:m...@bitchin100.com> Subject: Re: [M100] Listserv Search ALERT: Beginner asking question. Reminder: Upon hard reset the LCD initializes perfectly and displays the main Menu screen perfectly. However, once in BASIC or TEXT the bottom four lines do not display correctly. (See attached.) (Planned to test LCD in M102 but it has a different connector. I don't have a second M100 right now to test it in, but I am 99.99% positive the LCD is fine) So I purchased a logic prob (Elenco LP-900) <https://www.jpmsupply.com/Logic-Probe-and-Pulser-Combination-Elenco-LP-900-p/80311.htm> to test chip select lines on the LCD connector (Pins 14, 12, 10, 8, 7, 16,15,13,11, 9, and CS1=Pin? - schematics blurry). As I unboxed it I remembered I never used one before. :) - Where do I place the pos and neg alligator clips? - Do I s
Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
Never give up, never surrender :-) -- John.
Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
On Tue, Jul 28, 2020 at 12:45 PM Chris Fezzler wrote: > :( Short lived. Worked for 2-day. Back to old glitch. > > Still, almost certainly the problem is at the connector then if tightening fixed it up for a time -- John.
Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
:( Short lived. Worked for 2-day. Back to old glitch. On Sunday, July 26, 2020, 06:26:04 PM EDT, Jeffrey Birt wrote: Excellent! Let us know! Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 5:19 PM To: m...@bitchin100.com Subject: Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search Working but "uncle" LOL. After logic prob test, I got some pliers and gently squeezed the LCD connector to ensure good contact with the clip and wires before reinstalling. Fired it up. Nothing. Blank screen. Warm boot, nothing. Hard rest, LCD pixels went dark momentarily. Then nothing. About to call it quits but something told me to switch off, hold just CTRL and BREAK while turning on (no reset button). It fired up perfect, all lines. Who knows? We'll see if it sticks before installing REXCPM. On Sunday, July 26, 2020, 05:42:36 PM EDT, Chris Fezzler wrote: For what it is worth, logic probe results for LCD connector chip select pins: CS01 (pin 18) = H CS20 (pin 14) = H CS21 (pin 12) = H CS22 (pin 10) = H CS23 (pin 8) = H CS24 (pin 7) = H CS25 (pin 16) = L CS26 (pin 15) = L CS27 (pin 13) = L CS28 (pin 11) = L CS29 (pin 9) = L I took the prob positive from C83 and ground from C8. On Sunday, July 26, 2020, 03:55:00 PM EDT, Chris Fezzler wrote: No after market ROM. Logically, I would think the fact that the top four lines are perfect, the hard reset produces a perfect Menu screen, and just the bottom four lines are garbled would be a clue where to look. I know nothing other than reading a lot off Internet. My instinct tells me the issue is a component that regulates power or signals to the LCD driver chips for the bottom half of the screen. The are getting power (because we see gibberish and the perfect Menu screen) but perhaps it is the wrong voltage or intermittent power or signal. Thoughts are: Capacitors C47 or C54 and or M17 and/or M25. But I don't know how to determine their impact on the issue. On Sunday, July 26, 2020, 11:25:01 AM EDT, Jeffrey Birt wrote: When comparing your two pictures, after rotating them right side up, I noticed just now that not only do you have blank blocks but some of the characters are reversed. That is really bizarre. I’m not sure if that points to a problem with how the LCD drivers are being configured/initialized or what data is being sent to them. If the driver ships are outputting a built-in font here it might be a chip configuration issue. If the display is always bit mapped, then it would be something else. Do you have any sort of aftermarket ROM installed? Very interesting problem. Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 9:47 AM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search Gladly. On Sunday, July 26, 2020, 08:36:06 AM EDT, Jeffrey Birt wrote: Can you attach a picture of the cold boot screen too? The positive and negative clips go to a +5 and ground source on the M100 PCB itself. The PPS setting if ‘Pulses Per Second’ when using it as a logic pulser, i.e. to inject a pulsing signal. On the chip select lines you should she them quickly toggling. Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Saturday, July 25, 2020 6:20 PM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search ALERT: Beginner asking question. Reminder: Upon hard reset the LCD initializes perfectly and displays the main Menu screen perfectly. However, once in BASIC or TEXT the bottom four lines do not display correctly. (See attached.) (Planned to test LCD in M102 but it has a different connector. I don't have a second M100 right now to test it in, but I am 99.99% positive the LCD is fine) So I purchased a logic prob (Elenco LP-900) to test chip select lines on the LCD connector (Pins 14, 12, 10, 8, 7, 16,15,13,11, 9, and CS1=Pin? - schematics blurry). As I unboxed it I remembered I never used one before. :) - Where do I place the pos and neg alligator clips? - Do I set the logic prob to 400PPS or 00.5PPS? - In checking the chip select lines, am I looking for HI, LO, or PULSE? I see no broken or corroded lines on the board. Thanks in advance. On Wednesday, July 22, 2020, 02:29:39 PM EDT, Jeffrey Birt wrote: This loss of an entire block is the symptom of a missing chip select. When the LCD driver chips are powered/reset they will drive every pixel on/black. When they receive the proper initialization, they will drive every pixel off/clear. It seems the rest and initialization steps are being done so commands are getting through (and the machine is booting so the LCD has to be initializing and responding). Each driver chip on the LCD controls one bloc
Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
Everything has a purpose, I guess. I learned to read a schematic better. I learned how to use a logic probe and my mutli-meter better. I got experience de-soldering. I replaced the internal battery. So if it holds, I'll have a sweet Model T with REXCPM installed. On Sunday, July 26, 2020, 06:26:04 PM EDT, Jeffrey Birt wrote: Excellent! Let us know! Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 5:19 PM To: m...@bitchin100.com Subject: Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search Working but "uncle" LOL. After logic prob test, I got some pliers and gently squeezed the LCD connector to ensure good contact with the clip and wires before reinstalling. Fired it up. Nothing. Blank screen. Warm boot, nothing. Hard rest, LCD pixels went dark momentarily. Then nothing. About to call it quits but something told me to switch off, hold just CTRL and BREAK while turning on (no reset button). It fired up perfect, all lines. Who knows? We'll see if it sticks before installing REXCPM. On Sunday, July 26, 2020, 05:42:36 PM EDT, Chris Fezzler wrote: For what it is worth, logic probe results for LCD connector chip select pins: CS01 (pin 18) = H CS20 (pin 14) = H CS21 (pin 12) = H CS22 (pin 10) = H CS23 (pin 8) = H CS24 (pin 7) = H CS25 (pin 16) = L CS26 (pin 15) = L CS27 (pin 13) = L CS28 (pin 11) = L CS29 (pin 9) = L I took the prob positive from C83 and ground from C8. On Sunday, July 26, 2020, 03:55:00 PM EDT, Chris Fezzler wrote: No after market ROM. Logically, I would think the fact that the top four lines are perfect, the hard reset produces a perfect Menu screen, and just the bottom four lines are garbled would be a clue where to look. I know nothing other than reading a lot off Internet. My instinct tells me the issue is a component that regulates power or signals to the LCD driver chips for the bottom half of the screen. The are getting power (because we see gibberish and the perfect Menu screen) but perhaps it is the wrong voltage or intermittent power or signal. Thoughts are: Capacitors C47 or C54 and or M17 and/or M25. But I don't know how to determine their impact on the issue. On Sunday, July 26, 2020, 11:25:01 AM EDT, Jeffrey Birt wrote: When comparing your two pictures, after rotating them right side up, I noticed just now that not only do you have blank blocks but some of the characters are reversed. That is really bizarre. I’m not sure if that points to a problem with how the LCD drivers are being configured/initialized or what data is being sent to them. If the driver ships are outputting a built-in font here it might be a chip configuration issue. If the display is always bit mapped, then it would be something else. Do you have any sort of aftermarket ROM installed? Very interesting problem. Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 9:47 AM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search Gladly. On Sunday, July 26, 2020, 08:36:06 AM EDT, Jeffrey Birt wrote: Can you attach a picture of the cold boot screen too? The positive and negative clips go to a +5 and ground source on the M100 PCB itself. The PPS setting if ‘Pulses Per Second’ when using it as a logic pulser, i.e. to inject a pulsing signal. On the chip select lines you should she them quickly toggling. Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Saturday, July 25, 2020 6:20 PM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search ALERT: Beginner asking question. Reminder: Upon hard reset the LCD initializes perfectly and displays the main Menu screen perfectly. However, once in BASIC or TEXT the bottom four lines do not display correctly. (See attached.) (Planned to test LCD in M102 but it has a different connector. I don't have a second M100 right now to test it in, but I am 99.99% positive the LCD is fine) So I purchased a logic prob (Elenco LP-900) to test chip select lines on the LCD connector (Pins 14, 12, 10, 8, 7, 16,15,13,11, 9, and CS1=Pin? - schematics blurry). As I unboxed it I remembered I never used one before. :) - Where do I place the pos and neg alligator clips? - Do I set the logic prob to 400PPS or 00.5PPS? - In checking the chip select lines, am I looking for HI, LO, or PULSE? I see no broken or corroded lines on the board. Thanks in advance. On Wednesday, July 22, 2020, 02:29:39 PM EDT, Jeffrey Birt wrote: This loss of an entire block is the symptom of a missing chip select. When the LCD driver chips are powered/reset they will drive every pixel on/black. When they receive the proper initialization, they will drive every pixel off
Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
Excellent! Let us know! Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 5:19 PM To: m...@bitchin100.com Subject: Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search Working but "uncle" LOL. After logic prob test, I got some pliers and gently squeezed the LCD connector to ensure good contact with the clip and wires before reinstalling. Fired it up. Nothing. Blank screen. Warm boot, nothing. Hard rest, LCD pixels went dark momentarily. Then nothing. About to call it quits but something told me to switch off, hold just CTRL and BREAK while turning on (no reset button). It fired up perfect, all lines. Who knows? We'll see if it sticks before installing REXCPM. On Sunday, July 26, 2020, 05:42:36 PM EDT, Chris Fezzler mailto:fezz...@yahoo.com> > wrote: For what it is worth, logic probe results for LCD connector chip select pins: CS01 (pin 18) = H CS20 (pin 14) = H CS21 (pin 12) = H CS22 (pin 10) = H CS23 (pin 8) = H CS24 (pin 7) = H CS25 (pin 16) = L CS26 (pin 15) = L CS27 (pin 13) = L CS28 (pin 11) = L CS29 (pin 9) = L I took the prob positive from C83 and ground from C8. On Sunday, July 26, 2020, 03:55:00 PM EDT, Chris Fezzler mailto:fezz...@yahoo.com> > wrote: No after market ROM. Logically, I would think the fact that the top four lines are perfect, the hard reset produces a perfect Menu screen, and just the bottom four lines are garbled would be a clue where to look. I know nothing other than reading a lot off Internet. My instinct tells me the issue is a component that regulates power or signals to the LCD driver chips for the bottom half of the screen. The are getting power (because we see gibberish and the perfect Menu screen) but perhaps it is the wrong voltage or intermittent power or signal. Thoughts are: Capacitors C47 or C54 and or M17 and/or M25. But I don't know how to determine their impact on the issue. On Sunday, July 26, 2020, 11:25:01 AM EDT, Jeffrey Birt mailto:bir...@soigeneris.com> > wrote: When comparing your two pictures, after rotating them right side up, I noticed just now that not only do you have blank blocks but some of the characters are reversed. That is really bizarre. I’m not sure if that points to a problem with how the LCD drivers are being configured/initialized or what data is being sent to them. If the driver ships are outputting a built-in font here it might be a chip configuration issue. If the display is always bit mapped, then it would be something else. Do you have any sort of aftermarket ROM installed? Very interesting problem. Jeff Birt From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 9:47 AM To: m...@bitchin100.com <mailto:m...@bitchin100.com> Subject: Re: [M100] Listserv Search Gladly. On Sunday, July 26, 2020, 08:36:06 AM EDT, Jeffrey Birt mailto:bir...@soigeneris.com> > wrote: Can you attach a picture of the cold boot screen too? The positive and negative clips go to a +5 and ground source on the M100 PCB itself. The PPS setting if ‘Pulses Per Second’ when using it as a logic pulser, i.e. to inject a pulsing signal. On the chip select lines you should she them quickly toggling. Jeff Birt From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Chris Fezzler Sent: Saturday, July 25, 2020 6:20 PM To: m...@bitchin100.com <mailto:m...@bitchin100.com> Subject: Re: [M100] Listserv Search ALERT: Beginner asking question. Reminder: Upon hard reset the LCD initializes perfectly and displays the main Menu screen perfectly. However, once in BASIC or TEXT the bottom four lines do not display correctly. (See attached.) (Planned to test LCD in M102 but it has a different connector. I don't have a second M100 right now to test it in, but I am 99.99% positive the LCD is fine) So I purchased a logic prob (Elenco LP-900) <https://www.jpmsupply.com/Logic-Probe-and-Pulser-Combination-Elenco-LP-900-p/80311.htm> to test chip select lines on the LCD connector (Pins 14, 12, 10, 8, 7, 16,15,13,11, 9, and CS1=Pin? - schematics blurry). As I unboxed it I remembered I never used one before. :) - Where do I place the pos and neg alligator clips? - Do I set the logic prob to 400PPS or 00.5PPS? - In checking the chip select lines, am I looking for HI, LO, or PULSE? I see no broken or corroded lines on the board. Thanks in advance. On Wednesday, July 22, 2020, 02:29:39 PM EDT, Jeffrey Birt mailto:bir...@soigeneris.com> > wrote: This loss of an entire block is the symptom of a missing chip select. When the LCD driver chips are powered/reset they will drive every pixel on/black. When they receive the
Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
Working but "uncle" LOL. After logic prob test, I got some pliers and gently squeezed the LCD connector to ensure good contact with the clip and wires before reinstalling. Fired it up. Nothing. Blank screen. Warm boot, nothing. Hard rest, LCD pixels went dark momentarily. Then nothing. About to call it quits but something told me to switch off, hold just CTRL and BREAK while turning on (no reset button). It fired up perfect, all lines. Who knows? We'll see if it sticks before installing REXCPM. On Sunday, July 26, 2020, 05:42:36 PM EDT, Chris Fezzler wrote: For what it is worth, logic probe results for LCD connector chip select pins: CS01 (pin 18) = HCS20 (pin 14) = HCS21 (pin 12) = HCS22 (pin 10) = HCS23 (pin 8) = HCS24 (pin 7) = HCS25 (pin 16) = LCS26 (pin 15) = LCS27 (pin 13) = LCS28 (pin 11) = LCS29 (pin 9) = L I took the prob positive from C83 and ground from C8. On Sunday, July 26, 2020, 03:55:00 PM EDT, Chris Fezzler wrote: No after market ROM. Logically, I would think the fact that the top four lines are perfect, the hard reset produces a perfect Menu screen, and just the bottom four lines are garbled would be a clue where to look. I know nothing other than reading a lot off Internet. My instinct tells me the issue is a component that regulates power or signals to the LCD driver chips for the bottom half of the screen. The are getting power (because we see gibberish and the perfect Menu screen) but perhaps it is the wrong voltage or intermittent power or signal. Thoughts are: Capacitors C47 or C54 and or M17 and/or M25. But I don't know how to determine their impact on the issue. On Sunday, July 26, 2020, 11:25:01 AM EDT, Jeffrey Birt wrote: When comparing your two pictures, after rotating them right side up, I noticed just now that not only do you have blank blocks but some of the characters are reversed. That is really bizarre. I’m not sure if that points to a problem with how the LCD drivers are being configured/initialized or what data is being sent to them. If the driver ships are outputting a built-in font here it might be a chip configuration issue. If the display is always bit mapped, then it would be something else. Do you have any sort of aftermarket ROM installed? Very interesting problem. Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 9:47 AM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search Gladly. On Sunday, July 26, 2020, 08:36:06 AM EDT, Jeffrey Birt wrote: Can you attach a picture of the cold boot screen too? The positive and negative clips go to a +5 and ground source on the M100 PCB itself. The PPS setting if ‘Pulses Per Second’ when using it as a logic pulser, i.e. to inject a pulsing signal. On the chip select lines you should she them quickly toggling. Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Saturday, July 25, 2020 6:20 PM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search ALERT: Beginner asking question. Reminder: Upon hard reset the LCD initializes perfectly and displays the main Menu screen perfectly. However, once in BASIC or TEXT the bottom four lines do not display correctly. (See attached.) (Planned to test LCD in M102 but it has a different connector. I don't have a second M100 right now to test it in, but I am 99.99% positive the LCD is fine) So I purchased a logic prob (Elenco LP-900) to test chip select lines on the LCD connector (Pins 14, 12, 10, 8, 7, 16,15,13,11, 9, and CS1=Pin? - schematics blurry). As I unboxed it I remembered I never used one before. :) - Where do I place the pos and neg alligator clips? - Do I set the logic prob to 400PPS or 00.5PPS? - In checking the chip select lines, am I looking for HI, LO, or PULSE? I see no broken or corroded lines on the board. Thanks in advance. On Wednesday, July 22, 2020, 02:29:39 PM EDT, Jeffrey Birt wrote: This loss of an entire block is the symptom of a missing chip select. When the LCD driver chips are powered/reset they will drive every pixel on/black. When they receive the proper initialization, they will drive every pixel off/clear. It seems the rest and initialization steps are being done so commands are getting through (and the machine is booting so the LCD has to be initializing and responding). Each driver chip on the LCD controls one block of pixels. If an entire block is missing, it is a good sign the chip select is not getting through. It could be a bad trace on the M100, a bad LCD cable or a bad LCD itself. If you have a scope of logic probe you can check to see if all the chip select lines are toggling. Jeff BIrt From: M100 On Behalf Of Chris Fezzler Sent: Wednesday, July 22, 2020 11:26 AM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search Here you go. On Wedn
Re: [M100] LCD Botton 4 Lines (WAS) Listserv Search
For what it is worth, logic probe results for LCD connector chip select pins: CS01 (pin 18) = HCS20 (pin 14) = HCS21 (pin 12) = HCS22 (pin 10) = HCS23 (pin 8) = HCS24 (pin 7) = HCS25 (pin 16) = LCS26 (pin 15) = LCS27 (pin 13) = LCS28 (pin 11) = LCS29 (pin 9) = L I took the prob positive from C83 and ground from C8. On Sunday, July 26, 2020, 03:55:00 PM EDT, Chris Fezzler wrote: No after market ROM. Logically, I would think the fact that the top four lines are perfect, the hard reset produces a perfect Menu screen, and just the bottom four lines are garbled would be a clue where to look. I know nothing other than reading a lot off Internet. My instinct tells me the issue is a component that regulates power or signals to the LCD driver chips for the bottom half of the screen. The are getting power (because we see gibberish and the perfect Menu screen) but perhaps it is the wrong voltage or intermittent power or signal. Thoughts are: Capacitors C47 or C54 and or M17 and/or M25. But I don't know how to determine their impact on the issue. On Sunday, July 26, 2020, 11:25:01 AM EDT, Jeffrey Birt wrote: When comparing your two pictures, after rotating them right side up, I noticed just now that not only do you have blank blocks but some of the characters are reversed. That is really bizarre. I’m not sure if that points to a problem with how the LCD drivers are being configured/initialized or what data is being sent to them. If the driver ships are outputting a built-in font here it might be a chip configuration issue. If the display is always bit mapped, then it would be something else. Do you have any sort of aftermarket ROM installed? Very interesting problem. Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Sunday, July 26, 2020 9:47 AM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search Gladly. On Sunday, July 26, 2020, 08:36:06 AM EDT, Jeffrey Birt wrote: Can you attach a picture of the cold boot screen too? The positive and negative clips go to a +5 and ground source on the M100 PCB itself. The PPS setting if ‘Pulses Per Second’ when using it as a logic pulser, i.e. to inject a pulsing signal. On the chip select lines you should she them quickly toggling. Jeff Birt From: M100 On Behalf Of Chris Fezzler Sent: Saturday, July 25, 2020 6:20 PM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search ALERT: Beginner asking question. Reminder: Upon hard reset the LCD initializes perfectly and displays the main Menu screen perfectly. However, once in BASIC or TEXT the bottom four lines do not display correctly. (See attached.) (Planned to test LCD in M102 but it has a different connector. I don't have a second M100 right now to test it in, but I am 99.99% positive the LCD is fine) So I purchased a logic prob (Elenco LP-900) to test chip select lines on the LCD connector (Pins 14, 12, 10, 8, 7, 16,15,13,11, 9, and CS1=Pin? - schematics blurry). As I unboxed it I remembered I never used one before. :) - Where do I place the pos and neg alligator clips? - Do I set the logic prob to 400PPS or 00.5PPS? - In checking the chip select lines, am I looking for HI, LO, or PULSE? I see no broken or corroded lines on the board. Thanks in advance. On Wednesday, July 22, 2020, 02:29:39 PM EDT, Jeffrey Birt wrote: This loss of an entire block is the symptom of a missing chip select. When the LCD driver chips are powered/reset they will drive every pixel on/black. When they receive the proper initialization, they will drive every pixel off/clear. It seems the rest and initialization steps are being done so commands are getting through (and the machine is booting so the LCD has to be initializing and responding). Each driver chip on the LCD controls one block of pixels. If an entire block is missing, it is a good sign the chip select is not getting through. It could be a bad trace on the M100, a bad LCD cable or a bad LCD itself. If you have a scope of logic probe you can check to see if all the chip select lines are toggling. Jeff BIrt From: M100 On Behalf Of Chris Fezzler Sent: Wednesday, July 22, 2020 11:26 AM To: m...@bitchin100.com Subject: Re: [M100] Listserv Search Here you go. On Wednesday, July 22, 2020, 11:52:23 AM EDT, Stephen Adolph wrote: a pic of the garbled screen would be great if you can do it.. thanks On Wed, Jul 22, 2020 at 11:37 AM Chris Fezzler wrote: Sorry - typing too fast. Top four lines of the screen. Yes, mostly garbage all of the time. Except a hard rest will generate a proper menu screen. Yes, in BASIC the same. But if I type in a test program and hit RUN the program will indeed run. So the computer is getting the commands/keystrokes. Just not displaying bottom four lines. I think it is a component issue.
