Using the new logic analyzer and can see that the CPU appears to be working. It comes out of reset 200ms after receiving it's VCC signal. And there is data on the address and data busses. Clock signals are there. But it's still very difficult to understand the data I'm seeing and where to look. I keep thinking about the display that's off entirely. I need to know if the VFD is dead. I'm not sure how to test it. I did recheck the floating power rails and noticed some ripple on the -28V rail. It was also only about -27V. I check it's filter cap and sure enough one of the caps was open. Easy fix.
Does any one have any advice on how to verify a bad VFD without just replacing it? The face plate is a work of art. I don't want to disassemble the board as getting the LED in line again looks tedious. The VFD is getting it's +40v, +5v and 0v. Should I expect to see something on one spot of the VFD when it's powered up, or do I need to drive some logic HI or LO into it? Thanks Rick ******************** On Tue, Apr 28, 2020 at 12:33 PM Rick Bale <[email protected]> wrote: > I've order a few tools to make this more fun and less tedious. I should > have the following items next week. > > Inno-Maker LA2016 USB logic analyzer > 40-pin chip clip > 24-pin chip clip > > While I'm waiting for these I've been studying how the logic work from the > service manual. There's a lot of revealing info in there. Since I have > several more days until they arrive I will take some time to check if the > display is receiving any instructions. It would be a shame if the VFD was > simply dead in addition to all the LEDs being stuck on. > > Rick > > > On Mon, Apr 20, 2020 at 6:24 PM Didier Juges <[email protected]> wrote: > >> Rick, >> >> Maybe not the solution to your particular problem but for $5.00 (on >> AliExpress) or $10 (on Amazon) you can get an amazingly useful 25 MHz, 8 >> channel logic analyzer. >> >> You can use it with sigrok, free software that comes with a large number >> of >> protocol decoders. >> >> I just got one and I have used it quite a bit in the last couple of months >> to troubleshoot serial data issues with a UART and I2C issues that would >> have been extremely hard or impossible with my digital storage >> oscilloscope. >> >> It's not a replacement for a scope but a very useful complement and far >> and >> away the best $5 I have ever spent on anything. >> >> It may not be useful when troubleshooting buses wider than 8 bits or >> faster >> than a few MHz but everyone should have one of those. >> >> For a few $ more, they do have faster, 16 bit models. >> >> Didier KO4BB >> >> >> >> On Mon, Apr 20, 2020, 1:33 PM Rick Bale <[email protected]> wrote: >> >> > I's been a while since I last posted on my 7081. I needed to wait to >> > receive new earthy CPU and DMA chips. They are cheap and easy to >> swap. So >> > far, with Joe's help, I've replaced the earthy side PROMS. Also new is >> all >> > the RAM, DMA and microprocessor. I also went back and rechecked all the >> > power rails. I found a little extra noise on the +5v & +40v power >> rails. >> > I corrected this by replacing C56, C57, C58 filter caps. They all >> measured >> > about 50% or less of their original uF. The 12v filter C59 was okay. >> > >> > I have the same symptom of all LED stuck on and nothing on the screen. >> I >> > feel like I need to check the data during boot up. Probably means >> decoding >> > the logic. Maybe it's hung on a reset since all the LEDs are on. It >> would >> > seem reasonable that they would all come on during boot up or on a >> reset. >> > The problem is I don't have a logic analyzer or probe but mainly don't >> > really know where to start in the circuit. >> > >> > Does anyone have any suggestions on where to start. Do you think I >> should >> > move the conversation to the Solartron Group? >> > >> > Thanks, Rick >> > >> > >> > >> > > ---------------------------------------------------------------------- >> > > >> > > Message: 1 >> > > Date: Wed, 8 Apr 2020 13:23:17 -0400 >> > > From: Rick Bale <[email protected]> >> > > To: [email protected] >> > > Subject: Re: [volt-nuts] Solartron 7081 >> > > Message-ID: >> > > < >> > > cad2mu-meqokcshn2ljj4ako1whteuyk2mdjurg51pyhmsgn...@mail.gmail.com> >> > > Content-Type: text/plain; charset="UTF-8" >> > > >> > > Thank you David that is good information. This is good news is I have >> > the >> > > correct PROMs. My board is the 70810504X with 2564 PROMs. Joe has >> > > programmed up a new set of PROM's plus I have the old ones. >> > > >> > > I'll reassemble the unit after doing an alcohol scrub down on all the >> > > boards because there evidence of water damage on the top cover's >> shield. >> > > It's turned the shield green and has a mildew smell. Joe saw some >> > corrosion >> > > on the old PROMs too. In the long run I'll need to replace the >> cover's >> > > inside shield. I should be able order a custom one from a PCB shop as >> > it's >> > > just a large un-etched tin coated PCB board. >> > > >> > > If the cleaning doesn't work then it seems like I need to find a test >> > point >> > > to monitor the boot up data stream. Does that seem like a good place >> > > to start since power rails are good? Is it best to watch it from the >> GPIB >> > > connection? >> > > >> > > Rick >> > > >> > > >> > > >> > > > Message: 2 >> > > > Date: Wed, 8 Apr 2020 14:17:52 +0100 >> > > > From: "David C. Partridge" <[email protected]> >> > > > To: "'Discussion of precise voltage measurement'" >> > > > <[email protected]> >> > > > Subject: Re: [volt-nuts] Solartron 7081 >> > > > Message-ID: <[email protected]> >> > > > Content-Type: text/plain; charset="us-ascii" >> > > > >> > > > There is a downloadable high quality scan of the Service Manual >> which I >> > > > produced a while ago, that you can download from here: >> > > > >> > > > < >> > > > >> > > >> > >> https://groups.io/g/Solartron_Schlumberger_Equipment/files/Solartron%207071 >> > > > %20and%207081 >> > > > < >> > > >> > >> https://groups.io/g/Solartron_Schlumberger_Equipment/files/Solartron%207071%20and%207081 >> > > > >> > > > > >> > > > >> > > > It has the schematics for both the early (7504) and late (7514) >> earthy >> > > > processor boards, and contains numerous corrections to the text and >> > parts >> > > > lists. The schematics have been cleaned up and corrected where >> > > necessary. >> > > > >> > > > You can tell which ROMS the earthy processor uses based on the board >> > > > number: >> > > > Board 70817504 uses 2564s while 70817514 uses 2764s. >> > > > >> > > > If you use the wrong ROMs - it won't work! >> > > > >> > > > The Test Spec document is also of interest. >> > > > >> > > > Keep well >> > > > D >> > > > >> > > > -----Original Message----- >> > > > From: volt-nuts [mailto:[email protected]] On >> Behalf Of >> > > > Rick >> > > > Bale >> > > > Sent: 08 April 2020 13:45 >> > > > To: [email protected] >> > > > Subject: [volt-nuts] Solartron 7081 >> > > > >> > > > All, >> > > > >> > > > Here's an update on my 7081 that hangs during boot up >> > > > >> > > > >> > > > >> > > > >> > > > ------------------------------ >> > > > >> > > > Message: 3 >> > > > Date: Wed, 8 Apr 2020 14:29:09 +0100 >> > > > From: "David C. Partridge" <[email protected]> >> > > > To: "'Discussion of precise voltage measurement'" >> > > > <[email protected]> >> > > > Subject: Re: [volt-nuts] Solartron 7081 >> > > > Message-ID: <[email protected]> >> > > > Content-Type: text/plain; charset="us-ascii" >> > > > >> > > > Grrr why was my link split across two lines - it was sent as one >> line >> > ... >> > > > >> > > > Be warned you'll need to re-constitute the link ... >> > > > >> > > > David >> > > > >> > > > -----Original Message----- >> > > > From: volt-nuts [mailto:[email protected]] On >> Behalf Of >> > > > David >> > > > C. Partridge >> > > > Sent: 08 April 2020 14:18 >> > > > To: 'Discussion of precise voltage measurement' >> > > > Subject: Re: [volt-nuts] Solartron 7081 >> > > > >> > > > There is a downloadable high quality scan of the Service Manual >> which I >> > > > produced a while ago, that you can download from here: >> > > > >> > > > < >> > > > >> > > >> > >> https://groups.io/g/Solartron_Schlumberger_Equipment/files/Solartron%207071 >> > > > %20and%207081 >> > > > < >> > > >> > >> https://groups.io/g/Solartron_Schlumberger_Equipment/files/Solartron%207071%20and%207081 >> > > > >> > > > > >> > > > >> > > > It has the schematics for both the early (7504) and late (7514) >> earthy >> > > > processor boards, and contains numerous corrections to the text and >> > parts >> > > > lists. The schematics have been cleaned up and corrected where >> > > necessary. >> > > > >> > > > You can tell which ROMS the earthy processor uses based on the board >> > > > number: >> > > > Board 70817504 uses 2564s while 70817514 uses 2764s. >> > > > >> > > > If you use the wrong ROMs - it won't work! >> > > > >> > > > The Test Spec document is also of interest. >> > > > >> > > > Keep well >> > > > D >> > > > >> > > > -----Original Message----- >> > > > From: volt-nuts [mailto:[email protected]] On >> Behalf Of >> > > > Rick >> > > > Bale >> > > > Sent: 08 April 2020 13:45 >> > > > To: [email protected] >> > > > Subject: [volt-nuts] Solartron 7081 >> > > > >> > > > All, >> > > > >> > > > Here's an update on my 7081 that hangs during boot up >> > > > >> > > > >> > > > _______________________________________________ >> > > > volt-nuts mailing list -- [email protected] >> > > > To unsubscribe, go to >> > > > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com >> > > > and follow the instructions there. >> > > > >> > > > >> > > > >> > > > >> > > > ------------------------------ >> > > > >> > > > Message: 4 >> > > > Date: Wed, 8 Apr 2020 13:33:48 +0000 >> > > > From: Shaun Merrigan <[email protected]> >> > > > To: Discussion of precise voltage measurement >> > > > <[email protected]> >> > > > Subject: Re: [volt-nuts] Solartron 7081 >> > > > Message-ID: >> > > > < >> > > > >> > > >> > >> mwhpr22mb0142778e26799873fc21114bda...@mwhpr22mb0142.namprd22.prod.outlook.com >> > > > > >> > > > >> > > > Content-Type: text/plain; charset="Windows-1252" >> > > > >> > > > Rick, >> > > > >> > > > I have two 7081?s with the relevant configuration as follows: >> > > > >> > > > S\N 1395 with board 70817514 and 2764 ROMS >> > > > S\N 415 with board 70817504 and 2564 ROMS >> > > > >> > > > I can also confirm that swapping ROMS between the board revisions >> does >> > > not >> > > > work. >> > > > >> > > > Hope this helps. >> > > > >> > > > Shaun Merrigan >> > > > https://www.shaunmerrigan.info >> > > > >> > > > ________________________________ >> > > > From: volt-nuts <[email protected]> on behalf of >> David >> > C. >> > > > Partridge <[email protected]> >> > > > Sent: Wednesday, April 8, 2020 7:17:52 AM >> > > > To: 'Discussion of precise voltage measurement' < >> > > [email protected]> >> > > > Subject: Re: [volt-nuts] Solartron 7081 >> > > > >> > > > There is a downloadable high quality scan of the Service Manual >> which I >> > > > produced a while ago, that you can download from here: >> > > > >> > > > < >> > > > >> > > >> > >> https://groups.io/g/Solartron_Schlumberger_Equipment/files/Solartron%207071 >> > > > %20and%207081 >> > > > < >> > > >> > >> https://groups.io/g/Solartron_Schlumberger_Equipment/files/Solartron%207071%20and%207081 >> > > > >> > > > > >> > > > >> > > > It has the schematics for both the early (7504) and late (7514) >> earthy >> > > > processor boards, and contains numerous corrections to the text and >> > parts >> > > > lists. The schematics have been cleaned up and corrected where >> > > necessary. >> > > > >> > > > You can tell which ROMS the earthy processor uses based on the board >> > > > number: >> > > > Board 70817504 uses 2564s while 70817514 uses 2764s. >> > > > >> > > > If you use the wrong ROMs - it won't work! >> > > > >> > > > The Test Spec document is also of interest. >> > > > >> > > > Keep well >> > > > D >> > > > >> > > > -----Original Message----- >> > > > From: volt-nuts [mailto:[email protected]] On >> Behalf Of >> > > > Rick >> > > > Bale >> > > > Sent: 08 April 2020 13:45 >> > > > To: [email protected] >> > > > Subject: [volt-nuts] Solartron 7081 >> > > > >> > > > All, >> > > > >> > > > Here's an update on my 7081 that hangs during boot up >> > > > >> > > > >> > > > _______________________________________________ >> > > > volt-nuts mailing list -- [email protected] >> > > > To unsubscribe, go to >> > > > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com >> > > > and follow the instructions there. >> > > > >> > > > >> > > > ------------------------------ >> > > > >> > > > Subject: Digest Footer >> > > > >> > > > _______________________________________________ >> > > > volt-nuts mailing list >> > > > [email protected] >> > > > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com >> > > > >> > > > >> > > > ------------------------------ >> > > > >> > > > End of volt-nuts Digest, Vol 125, Issue 1 >> > > > ***************************************** >> > > > >> > > >> > > >> > > ------------------------------ >> > > >> > > Subject: Digest Footer >> > > >> > > _______________________________________________ >> > > volt-nuts mailing list >> > > [email protected] >> > > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com >> > > >> > > >> > > ------------------------------ >> > > >> > > End of volt-nuts Digest, Vol 125, Issue 2 >> > > ***************************************** >> > > >> > _______________________________________________ >> > volt-nuts mailing list -- [email protected] >> > To unsubscribe, go to >> > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com >> > and follow the instructions there. >> > >> _______________________________________________ >> volt-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com and follow the instructions there.
