retrolimber
New member
Hi there from Italy! I'm new here. I have a Lisa 1 computer upgraded to 2. The machine sadly is not working.
I started with a bad DataPower 1A PSU that I recapped and now it works.
On the CPU board I found a bad EPROM so I wrote them again on 2 brand new 2764-30 EPROMs. I replaced the VSROM socket that was partially broken.
The seller that sold the Lisa to me said that he tested the I/O board and motherboard on another machine and everything was working. The CPU board was not working.
There are no signs of battery leak damage in the boards as the battery pack has been removed more than 20 years ago.
The problem: when I turn the computer on with everything in the card cage I get a white screen with raster lines. Now the odd part: if I remove the system I/O board
the Lisa shows me a CPU error with code 41. I think this is normal as she can't see the I/O board?
It is funny, as if I put the I/O board back in the card cage and I remove the SY6504 it shows the same error 41. The I/O board was working 2 weeks ago in another Lisa.
The 341-0290, the 6504 itself, the two 6522, the COP421, the 2 2114 RAMs and 8530 from what I can say are working. The power button works as it should if the I/O board is present.
What could be the problem and what should I try next? Thanks in advance!
Alessandro
I started with a bad DataPower 1A PSU that I recapped and now it works.
On the CPU board I found a bad EPROM so I wrote them again on 2 brand new 2764-30 EPROMs. I replaced the VSROM socket that was partially broken.
The seller that sold the Lisa to me said that he tested the I/O board and motherboard on another machine and everything was working. The CPU board was not working.
There are no signs of battery leak damage in the boards as the battery pack has been removed more than 20 years ago.
The problem: when I turn the computer on with everything in the card cage I get a white screen with raster lines. Now the odd part: if I remove the system I/O board
the Lisa shows me a CPU error with code 41. I think this is normal as she can't see the I/O board?
It is funny, as if I put the I/O board back in the card cage and I remove the SY6504 it shows the same error 41. The I/O board was working 2 weeks ago in another Lisa.
The 341-0290, the 6504 itself, the two 6522, the COP421, the 2 2114 RAMs and 8530 from what I can say are working. The power button works as it should if the I/O board is present.
What could be the problem and what should I try next? Thanks in advance!
Alessandro
