Re: lisa 2 startup problems

Tested further, removed the TL amplifier chip for the contrast and now i have a sharp image but the white lines / scrambled screen is still there, i can see the error code 41, what does it really mean "selection logic problem" ? Is there anywhere some description about the selection logic?

Best regards,
Alex

sâmbătă, 12 ianuarie 2013, 13:01:37 UTC+2, Alex a scris:
>
> Hello everybody,
>
>
> James you might be right, I think it is possible I have hot-plugged the
> floppy drive (connected and disconnected the ribon cable with the Lisa
> working)
>
> I worked a lot today to find the cause for the new problem of the IO
> Board, i found out that when I desolder and remove U7B, I can get a CPU
> Error on the screen, the image is very fuzzy tough and not very readable, I
> have tried to desolder and remove all chips directly connected to the
> adress bus and data bus and nothing changed, when I removed U7B i could
> finally get this image:
> http://imageshack.us/photo/my-images/405/dsc0508q.jpg/ otherwise, the
> white
>
> I have installed and soldered the all removed chips one by one and found
> out that U7B is a link to the problem, I say link because i replaced it
> with a new chip and the white screen with the cpu error can not be seen any
> more. but the rest of the screen remains the same.
>
> Now, I cannot make any more tests because I don't whant to fight to my
> girlfriend but I have to test the chips related to the FDC Controller.
>
>

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