Amiga 4000D Black Screen (Paula / FastMEM / Full Recap) Repair
First of all, a premise: All the repairs i do are for hobby purpose ONLY. It is NOT a job, and i fix stuff for a selected people group that i consider needs my help. All other people please ask somewhere else to get your items repaired back.
A guy contacted me asking help for a repair and after an exchange of messages i agreed to repair his Amiga 4000 which at boot only displayed a Black screen.
I immediately noticed a fairly important damage caused by battery and caps acid leakage.
After cleaned everything and replaced capacitors on motherboard / 3640 and PSU (the fault persisted, of course).
Next, i used the Chucky DIAGROM: the DIAGROM is useful to understand what might be that doesn’t work, and the output via RS232 is also very useful if nothing is displayed on the screen.
Unfortunately the DIAGROM worked partially because the mouse was completely dead and therefore i have used the output via Serial but this is also worked partially because evidently also the serial is dead but in some precarious moments i have tried to run the Sound test and no sound was reproduced.
Moral: Partially working Serial port + Mouse not working + Audio not working = Paula.
Replaced the PAULA (U400) everything started to work correctly apart the FASTRAM with 4 x 4MB SIMM modules each the system sees only 2 in the U852/U853 positions for a total of 8MB.
The problem was a short circuit probably caused by the acid leaking from the battery, i had to clean the PCB for the tenth time and the problem was fixed.
No more other to say, except that i am happy i succeeded to repaired this Amiga 4000 for a person that needed my help.
Gallery of the repair:
Video:
Hi!
Can you tell me if Diagrom printed some garbage between the lines in the serial output when paula was bad?
I have probably diagnosed one of my A4000s with at bad paula now where symptoms are (when diagrom is installed) :
- Garbage between the lines printed out via the serialport
- Right mousebutton is registered as pressed during poweron.
The system crashes normally before the menu is displayed. Sometimes the menu is displayed, but I can’t select anything from the remote computer. The system has probably crashed already, and nothing more happens.
My guess is paula because of the garbage output from the serialport and the stuck RMB. Paula does not handle the mouse movement as far as I can see, only the buttons.
I’m of course unable to test audio, because its not possible before it crashes.
Any tips? :)
hi are you still repairing amiga a4000d ? i have a black screen. it hada green screen for a bit as well.
jody from new brunswick ,canada