General Category > Lisa Troubleshooting and Repair
Lisa Video, ProFile power issue, NiCad Leak fixes, etc.
AlexTheCat123:
--- Quote ---By Select you mean !CS on pin 8 of the two SRAMs, yes?
--- End quote ---
No. I'm talking about the S signal that feeds into the three LS157 muxes that select between the shared RAM being addressed by the 68000 and the RAM being addressed by the 6504.
The /DTACK signal that comes out of the 8T97 on the schematic also seems to suffer from the same problem where it goes low for a much shorter period of time when the Lisa fails to properly access the shared RAM compared to when it succeeds.
Lisa2:
--- Quote from: rayarachelian on June 17, 2021, 06:08:51 pm ---D'Oh! Thanks for that. That came from here: https://lisaem.sunder.net/cgi-bin/bookview2.cgi?zoom=0?page=8?book=6?Go=Go and is labeled "Lisa 1 I/O Board 4" - are the ones labeled "Lisa210Sys" swapped with the "Lisa1" ones?
--- End quote ---
I/O sheet four for both the 2/5 and 2/10 appear to be the same on the sunder site....
AlexTheCat123:
I think I fixed it! It looks like the 8T97 that buffers the /DTACK signal was flaky and after replacing it the Lisa boots from floppy just fine!. Unfortunately, the ProFile started dying at around the same time. It takes forever to complete the self-test and the LOS installer will fail to initialize it. Would a low-level format be likely to fix this?
rayarachelian:
--- Quote from: AlexTheCat123 on June 19, 2021, 06:53:37 am ---I think I fixed it! It looks like the 8T97 that buffers the /DTACK signal was flaky and after replacing it the Lisa boots from floppy just fine!. Unfortunately, the ProFile started dying at around the same time. It takes forever to complete the self-test and the LOS installer will fail to initialize it. Would a low-level format be likely to fix this?
--- End quote ---
Yeay! Glad you found it.
Maybe. Does NeoWidex tell you how many spared blocks there are? if there are just a few it may help, if there are a lot, it might not help at all (indicating physical damage).
But, if it's not working, and it's not an electrical issue, not much left to lose, right?
Before you do that though, is that VIA ok? Remind me again, before the power issues, was the ProFile working before, or is that an unknown?
So far you've replaced the 8T97, and the 6504, right? that indicates issues on the I/O board, what could have damaged these guys? Any chance the parallel port VIA has gone bad too? Or something from it to the port?
If at least NeoWidex is able to read blocks off the profile, especially the spare table, it should say the name is "PROFILE" at minimum and tell you it's 5MB, etc. and how many spared blocks there are, then there likely isn't a communication issue, but rather a media issue.
AlexTheCat123:
--- Quote ---Maybe. Does NeoWidex tell you how many spared blocks there are?
--- End quote ---
It says that all 20 (I'm assuming that this in in hex) spares are in use and that there are 1D bad blocks on the disk. Would a low-level format potentially help or is this drive too far gone?
--- Quote ---Before you do that though, is that VIA ok?
--- End quote ---
I know that everything on the I/O board is just fine because my Cameo/Aphid works perfectly with it.
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