Hi all
Trying to repair my a1200, it was not showing any signs of life before, even with diagrom. I started by retouching the solder on the alice chip.
I am now get some display with diagrom some raster bars with flashing green background.
I'm now also getting the following through the serial output
HTML Code:
Garbage before this text was binary numbers: 1, 2, 4, 8, 16, 32, 64, @???U
Garbage before this text was binary numbers: 1, 2, 4, 8, 16, 32, 64, 128, 240, 15, 170 and 85
To help you find biterrors to paula. Now starting normal startuptext etc
Amiga DiagROM V1.2 - 13-Aug-19 - By John (Chucky/The Gang) Hertell
Testing if serial loopbackadapter is installed: <> NOT DETECTED
- Parallel Code $ff - Start of ROM, CPU Seems somewhat alive
Checking status of mousebuttons for different startups:
Set all Interrupt enablebits (INTENA $dff09a) to Disabled: Done
Set all Interrupt requestbits (INTREQ $dff09c) to Disabled: Done
Set all DMA enablebits (DMACON $dff096) to Disabled: Done
Testing if OVL is working: OK
- Parallel Code $fe - Test UDS/LDS line
- Test of writing word $FFFF to $400 OK
- Test of writing word $00FF to $400 OK
- Test of writing word $FF00 to $400 OK
- Test of writing word $0000 to $400 OK
- Test of writing byte (even) $ff to $400 OK
- Test of writing byte (odd) $ff to $401 OK
- Parallel Code $fd - Start of chipmemdetection
Addr $00008400 OK Number of 32K blocks found: $01
Chipmem Shadowram detected, guess there is no more chipmem, stopping here
Startaddr: $00000400 Endaddr: $00007FFF
- Parallel Code $fc - Trying to find some fastmem (as no chipmem found)
- Parallel Code $fb - Memorydetection done
- Parallel Code $80 - NO Chipmem detected
- NO MEMORY FOUND - HALTING SYSTEM
The board looks ok with no obvious damage or broken traces, I have retiuched all the other chips as well fresh solder and flux.
I assumed it was bad ram, so i also desoldered all the ram and put in 2 good chips in U16 & U17 only, but it still shows the same problem.
Any help or pointers would be greatly appreciated