Re: [M100] Lighter rows of pixels on LCD
I always wondered if there was a compatible LCD green SuperTwist compatible screen for M100/M102/M200. Like the Amstrad PPC640 has. On Tuesday, February 26, 2019, 11:02:23 PM EST, John R. Hogerhuis wrote: Kind of comedic trying to keep his budget to $500. Hope he does it though. I wonder if modern tech allows for a faster display to replace the model 100 display? But with same daylight readable characteristics. -- John.
Re: [M100] Lighter rows of pixels on LCD
Wow! Those numbers are much more approachable than I realized. They are more like, 8th floor with no elevator, where I thought they would be outer space. This is awesome. On Tue, Feb 26, 2019 at 9:29 PM Josh Malone wrote: > It's still a WIP > > https://www.eevblog.com/forum/projects/lcd-design-is-this-good-enough/ > > On Tue, Feb 26, 2019 at 8:45 PM Kevin Becker > wrote: > > > > Someone made new PC-1 LCDs? Could you provide a link? > > > > - Kevin > > > > > > > On Feb 26, 2019, at 8:00 PM, Josh Malone > wrote: > > > > > >> On Tue, Feb 26, 2019 at 4:45 PM Fugu ME100 > wrote: > > >> > > >> I have used de-oxit on the edge of the elastomer to pcb contact in > the past – very, very sparingly to try and clean the PCB contacts. Then > used a piece of stiff card to very very gently push the elastomer in an > attempt to clean up the contacts. This tends to work for lines that are > blank rather than dim. The line is totally gone in this case either > horizontally or vertically and they tend not to repeat. > > >> > > >> With lines that are just a little dimmer than the rest I have not > found a good solution. If they are paired like this example it implies to > me that the driver chips are no longer working properly. The screen is > split in two parts driven by the same horizontal chips. So the 1&2 are the > same as 33 & 34 lines. > > >> > > >> As Jeff mentions check the –5V is close to –5V eg –4.89V or higher. > > >> > > >> The problem is not related to the battery replacement. It is simply > the age of the machine, the old LCD displays were prone to heat and > moisture problems and of course the chips themselves do age. > > >> > > >> Don’t be tempted to take the screen apart they are almost impossible > to get back together and work – yes I have tried it :) > > > > > > So have I. It doesn't end well. Due to their age, the zebra strips > > > have now been permanently deformed by the plating of the tracks on the > > > PCB (and possibly on the glass as well). I briefly looked to see if I > > > could find a vendor to make zebra strips the right size for the > > > M100/M102 displays but didn't find anything. These strips have to be > > > die-cut very precisely so that they apply even pressure to the LCD > > > electrodes and the PCB contacts. > > > > > > I think that if we could find a source for these elastomeric > > > connectors, we could "rehabilitate" a large number of M100 LCD > > > assemblies. Does anyone have good industrial contacts that might could > > > make these? I imagine we'd be looking at a multi-hundred min qty > > > purchase, but given the rarity of M100 LCDs I think it should be done. > > > If one guy can bring new PC-1 LCDs into the world, surely we can find > > > a source for this part. Right? > > > -- bkw
Re: [M100] Lighter rows of pixels on LCD
I don¹t think you damaged the screen it was probably like that before you touched it. They are very old machines and way beyond their expected EOL. Even fully functional machines can stop working after time in storage. I recently took out my favorite 102 after a few weeks of none use and it would not power up even after a cold reboot. Checked the batteries etc all fine opened it up checked the voltages internally, everything looked perfect, switched it on again and it worked. So they age and will fail. I found patience is a virtue with these machines :) The e-Ink idea sounds a great idea for a screen replacement. Wonder if there is a version that has a similar size? It would probably be quite easy to build the HW to map the LCD screen commands to the e-Ink screen. On 26/2/19, 9:15 PM, "M100 on behalf of Andrew Kennedy" wrote: >Great, so it sounds like I damaged a chip by not taking enough care with >the LCD board. And I was so proud of myself! >Oh well, thanks for the help guys. I unplugged and replugged the flex >cable that connects to the LCD board, but I'm not going to mess with it >any further on my own. > >John, I do wonder if e-Ink would be a good replacement. It doesn't have >to be high DPI, and the next generation should be plenty fast for the >Model T's purposes if the current generation isn't yet. >I bought a new e-reader recently, and I love the screen. It looks great >in any lighting, and uses very little power because it only uses >electricity to change a pixel's on/off state. >
Re: [M100] Lighter rows of pixels on LCD
Great, so it sounds like I damaged a chip by not taking enough care with the LCD board. And I was so proud of myself! Oh well, thanks for the help guys. I unplugged and replugged the flex cable that connects to the LCD board, but I'm not going to mess with it any further on my own. John, I do wonder if e-Ink would be a good replacement. It doesn't have to be high DPI, and the next generation should be plenty fast for the Model T's purposes if the current generation isn't yet. I bought a new e-reader recently, and I love the screen. It looks great in any lighting, and uses very little power because it only uses electricity to change a pixel's on/off state.
Re: [M100] Lighter rows of pixels on LCD
Kind of comedic trying to keep his budget to $500. Hope he does it though. I wonder if modern tech allows for a faster display to replace the model 100 display? But with same daylight readable characteristics. -- John.
Re: [M100] Lighter rows of pixels on LCD
It's still a WIP https://www.eevblog.com/forum/projects/lcd-design-is-this-good-enough/ On Tue, Feb 26, 2019 at 8:45 PM Kevin Becker wrote: > > Someone made new PC-1 LCDs? Could you provide a link? > > - Kevin > > > > On Feb 26, 2019, at 8:00 PM, Josh Malone wrote: > > > >> On Tue, Feb 26, 2019 at 4:45 PM Fugu ME100 wrote: > >> > >> I have used de-oxit on the edge of the elastomer to pcb contact in the > >> past – very, very sparingly to try and clean the PCB contacts. Then used > >> a piece of stiff card to very very gently push the elastomer in an attempt > >> to clean up the contacts. This tends to work for lines that are blank > >> rather than dim. The line is totally gone in this case either > >> horizontally or vertically and they tend not to repeat. > >> > >> With lines that are just a little dimmer than the rest I have not found a > >> good solution. If they are paired like this example it implies to me that > >> the driver chips are no longer working properly. The screen is split in > >> two parts driven by the same horizontal chips. So the 1&2 are the same as > >> 33 & 34 lines. > >> > >> As Jeff mentions check the –5V is close to –5V eg –4.89V or higher. > >> > >> The problem is not related to the battery replacement. It is simply the > >> age of the machine, the old LCD displays were prone to heat and moisture > >> problems and of course the chips themselves do age. > >> > >> Don’t be tempted to take the screen apart they are almost impossible to > >> get back together and work – yes I have tried it :) > > > > So have I. It doesn't end well. Due to their age, the zebra strips > > have now been permanently deformed by the plating of the tracks on the > > PCB (and possibly on the glass as well). I briefly looked to see if I > > could find a vendor to make zebra strips the right size for the > > M100/M102 displays but didn't find anything. These strips have to be > > die-cut very precisely so that they apply even pressure to the LCD > > electrodes and the PCB contacts. > > > > I think that if we could find a source for these elastomeric > > connectors, we could "rehabilitate" a large number of M100 LCD > > assemblies. Does anyone have good industrial contacts that might could > > make these? I imagine we'd be looking at a multi-hundred min qty > > purchase, but given the rarity of M100 LCDs I think it should be done. > > If one guy can bring new PC-1 LCDs into the world, surely we can find > > a source for this part. Right? >
Re: [M100] Lighter rows of pixels on LCD
Someone made new PC-1 LCDs? Could you provide a link? - Kevin > On Feb 26, 2019, at 8:00 PM, Josh Malone wrote: > >> On Tue, Feb 26, 2019 at 4:45 PM Fugu ME100 wrote: >> >> I have used de-oxit on the edge of the elastomer to pcb contact in the past >> – very, very sparingly to try and clean the PCB contacts. Then used a piece >> of stiff card to very very gently push the elastomer in an attempt to clean >> up the contacts. This tends to work for lines that are blank rather than >> dim. The line is totally gone in this case either horizontally or >> vertically and they tend not to repeat. >> >> With lines that are just a little dimmer than the rest I have not found a >> good solution. If they are paired like this example it implies to me that >> the driver chips are no longer working properly. The screen is split in >> two parts driven by the same horizontal chips. So the 1&2 are the same as >> 33 & 34 lines. >> >> As Jeff mentions check the –5V is close to –5V eg –4.89V or higher. >> >> The problem is not related to the battery replacement. It is simply the >> age of the machine, the old LCD displays were prone to heat and moisture >> problems and of course the chips themselves do age. >> >> Don’t be tempted to take the screen apart they are almost impossible to get >> back together and work – yes I have tried it :) > > So have I. It doesn't end well. Due to their age, the zebra strips > have now been permanently deformed by the plating of the tracks on the > PCB (and possibly on the glass as well). I briefly looked to see if I > could find a vendor to make zebra strips the right size for the > M100/M102 displays but didn't find anything. These strips have to be > die-cut very precisely so that they apply even pressure to the LCD > electrodes and the PCB contacts. > > I think that if we could find a source for these elastomeric > connectors, we could "rehabilitate" a large number of M100 LCD > assemblies. Does anyone have good industrial contacts that might could > make these? I imagine we'd be looking at a multi-hundred min qty > purchase, but given the rarity of M100 LCDs I think it should be done. > If one guy can bring new PC-1 LCDs into the world, surely we can find > a source for this part. Right?
Re: [M100] Lighter rows of pixels on LCD
On Tue, Feb 26, 2019 at 4:45 PM Fugu ME100 wrote: > > I have used de-oxit on the edge of the elastomer to pcb contact in the past – > very, very sparingly to try and clean the PCB contacts. Then used a piece of > stiff card to very very gently push the elastomer in an attempt to clean up > the contacts. This tends to work for lines that are blank rather than dim. > The line is totally gone in this case either horizontally or vertically and > they tend not to repeat. > > With lines that are just a little dimmer than the rest I have not found a > good solution. If they are paired like this example it implies to me that > the driver chips are no longer working properly. The screen is split in two > parts driven by the same horizontal chips. So the 1&2 are the same as 33 & > 34 lines. > > As Jeff mentions check the –5V is close to –5V eg –4.89V or higher. > > The problem is not related to the battery replacement. It is simply the age > of the machine, the old LCD displays were prone to heat and moisture problems > and of course the chips themselves do age. > > Don’t be tempted to take the screen apart they are almost impossible to get > back together and work – yes I have tried it :) So have I. It doesn't end well. Due to their age, the zebra strips have now been permanently deformed by the plating of the tracks on the PCB (and possibly on the glass as well). I briefly looked to see if I could find a vendor to make zebra strips the right size for the M100/M102 displays but didn't find anything. These strips have to be die-cut very precisely so that they apply even pressure to the LCD electrodes and the PCB contacts. I think that if we could find a source for these elastomeric connectors, we could "rehabilitate" a large number of M100 LCD assemblies. Does anyone have good industrial contacts that might could make these? I imagine we'd be looking at a multi-hundred min qty purchase, but given the rarity of M100 LCDs I think it should be done. If one guy can bring new PC-1 LCDs into the world, surely we can find a source for this part. Right?
Re: [M100] Lighter rows of pixels on LCD
I have used de-oxit on the edge of the elastomer to pcb contact in the past – very, very sparingly to try and clean the PCB contacts. Then used a piece of stiff card to very very gently push the elastomer in an attempt to clean up the contacts. This tends to work for lines that are blank rather than dim. The line is totally gone in this case either horizontally or vertically and they tend not to repeat. With lines that are just a little dimmer than the rest I have not found a good solution. If they are paired like this example it implies to me that the driver chips are no longer working properly. The screen is split in two parts driven by the same horizontal chips. So the 1&2 are the same as 33 & 34 lines. As Jeff mentions check the –5V is close to –5V eg –4.89V or higher. The problem is not related to the battery replacement. It is simply the age of the machine, the old LCD displays were prone to heat and moisture problems and of course the chips themselves do age. Don’t be tempted to take the screen apart they are almost impossible to get back together and work – yes I have tried it :) From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of Jeffrey Birt mailto:bir...@soigeneris.com>> Reply-To: mailto:m...@bitchin100.com>> Date: Tuesday, February 26, 2019 at 1:17 PM To: mailto:m...@bitchin100.com>> Subject: Re: [M100] Lighter rows of pixels on LCD Hi Andrew, The LCD glass is electrically connected to the PCB via an elastomeric ‘zebra’ strip. This is sort of like a silicone rubber strip with stipes of conductive material embedded to make electrical contact. If something got under between the PCB and zebra strip it might cause an issue like this. The metal frame around the LCD is what applies pressure to hold things in place. You can apply a bit of pressure to the edges to see if it changes. Also, check you power supply voltages. If the -10V for the LCD is low, it could cause problems and perhaps some driver chips would be more sensitive to the low voltage than others? Jeff_Birt (Hey_Birt!) From: M100 mailto:m100-boun...@lists.bitchin100.com>> On Behalf Of Andrew Kennedy Sent: Tuesday, February 26, 2019 2:42 PM To: m100 mailto:m100@lists.bitchin100.com>> Subject: [M100] Lighter rows of pixels on LCD Hi folks, thanks again for the advice the other day. I just replaced my NiCd, which had a light amount of leakage on the barrel but didn't appear to have reached the PCB. I put a NiMh in there, and the computer is plugged in to charge it up for a while. However, when I turn it on I'm noticing an annoying defect, there are two bars on the screen whose pixels are lighter than the others. The bars are at rows 1&2, and 33&34, counting 0 as the first row. The pixels still turn black, just not as black as the other rows of pixels. I tried searching the mail archives but didn't find any discussion about this. Could it be that the new battery just needs to charge more? I'm going to reseat the ZIF cable, but if there are any other ideas please let me know. - Andrew
Re: [M100] Lighter rows of pixels on LCD
Hi Andrew, The LCD glass is electrically connected to the PCB via an elastomeric ‘zebra’ strip. This is sort of like a silicone rubber strip with stipes of conductive material embedded to make electrical contact. If something got under between the PCB and zebra strip it might cause an issue like this. The metal frame around the LCD is what applies pressure to hold things in place. You can apply a bit of pressure to the edges to see if it changes. Also, check you power supply voltages. If the -10V for the LCD is low, it could cause problems and perhaps some driver chips would be more sensitive to the low voltage than others? Jeff_Birt (Hey_Birt!) From: M100 On Behalf Of Andrew Kennedy Sent: Tuesday, February 26, 2019 2:42 PM To: m100 Subject: [M100] Lighter rows of pixels on LCD Hi folks, thanks again for the advice the other day. I just replaced my NiCd, which had a light amount of leakage on the barrel but didn't appear to have reached the PCB. I put a NiMh in there, and the computer is plugged in to charge it up for a while. However, when I turn it on I'm noticing an annoying defect, there are two bars on the screen whose pixels are lighter than the others. The bars are at rows 1&2, and 33&34, counting 0 as the first row. The pixels still turn black, just not as black as the other rows of pixels. I tried searching the mail archives but didn't find any discussion about this. Could it be that the new battery just needs to charge more? I'm going to reseat the ZIF cable, but if there are any other ideas please let me know. - Andrew
