My nemesis - A500 Rev.5

[dunderdotten]

So i decided to put a Amiga 500 in my Studio/Mancave. I Bought a rev.5 motherboard with all necessary accessories incl. Gotek.
First i cleaned it and visually checked the components, they did look good.

First boot: Just a green screen.... Bad chip-ram... maybe.
I bought tools to extract all chips, clean/check the pins and also to clean the sockets.

Second try: Green screen. Fat Agnus! i thought to myself.... Bought a new one. Inserted.

Now it boots a white screen! Progress!

No seriously, This project is turning to a nightmare.

The leds on the keyboard turns on intermittently. No caps-lock code.

Screen can show different colors every boot the most common ones are white and black.
If i turn power on/off many times i can get colors like, yellow, green, red white and black...

Checked PSU with multimeter and it reads correct

When turned on for 15-20 min the only chips that gets "warm" is Denise, Paula and Odd Cia the other guys are stone-cold incl. the chip-ram...

There are so many symptoms now so i feel kinda lost. All tips are majestically welcome!

 

[ajk]

At some point it's easier to give up and get a replacement. The ailing motherboard can go to someone who is willing to investigate it further or just be used/sold for individual spare parts.

I've got an extra A500 for sale, works perfectly We even share the same type of keyboard layout if you want the whole thing.

 

[dunderdotten]

Agreed. How much are you willing to let your board go for?

 

[Atreus]

Don't give up so easily. First reaseat all chips in sockets on mobo. And of course clean their legs. If they are dirty or something, this can be an issue of your problems.
Sometimes this helps...

 

[dunderdotten]

Did the "regular" cleaning before posting Checked psu, bought a new "fat agnus" then i kinda gave up.... next to test would be ram/piggyleg

 

[8 Bit Dreams]

1. If You have Trapdoor memory expansion - remove it first, it causes issues quit often
2. Second step: get/burn yourself a DiagROM/Logica ROM and test memory, CIA and do other tests
3. green bootscreen points to bad CPU/corroded socket sometimes. if your Amiga doesen't boot with service rom - CPU may be the issue
4. it is much easier to get a working amiga, and test all socketed chips before You start to purchase replacements and desolder RAM.
regards,

-Cook

 

[TomCorbett]

Screen color and keyboard light blinks meanings.

Screen color and keyboard light blinks meanings.

Late reply, but I only just started on Amibay, but this is information I got from a youtube Amiga repair tutorial.

Screen colors: Normal boot

Dark Gray - The initial hardware tested OK. The 68000 is running and registers are readable.
Light Gray - The software is coming in and seems OK.
White - The initialization tests have passed.

Failed Boot Process
Red - Error was found in ROMS.
Green - Error found in the CHIP RAM.
Blue - Error was found in the custom chips.
Yellow - If 68000 found an error before the error trapping software (GURU) was running.

Keyboard Error Codes

One Blink - Keyboard ROM check failed.
Two Blinks - Keyboard RAM check failed.
Three Blinks - Watch dog timer failed.
Four Blinks - A short between two row lines or special control keys.

I hope this provides belated help, or can help someone else. The screen colors are very interesting to know.

Tom