amiga-A500-501s-0-5-meg-upgrade yellow screen.

[Dr. Chef]

I bought a 501s ram upgrade for my NTSC A500. The problem is when I turn the switch to the on position and turn on my A500, the screen turns yellow, however, if the ram is turned off, the Amiga boots fine. Is there a way to fix this? What about cleaning the ram or contacts? Is the ram dead?


This is what I purchased.
http://www.ebay.com/itm/311016244763


Thanks,

Dr. Chef.

[ElPolloDiabl]

Try replacing the battery.
Everything else seems fine.

[Dr. Chef]

I'll try that after work. I tried removing the battery, but I still had the yellow screen. Hopefully, its just a battery issue. Thank you.


Edit: I put in a new battery, but when I turned on the A500, I still get a yellow screen. Also, I forgot to note, that the power led would flash and after a while the screen would turn grey then yellow again. This doesn't happen if I remove the ram or turn off the ram.

[Dr. Chef]

I don't know what to do. Any ideas? I was able to replace the battery, but It still wont work. Yellow screen and flashing power led.


Thanks.

-Dr. Chef

[magnetic]

probably because there was some hack/mod done in regards to the ram like the 1mb chip upgrade?

[kjmann]

Sounds like one of the ram chips on the 501 are bad. the multiple power LED flashing and yellow screen would indicate that.

[ElPolloDiabl]

The guy had it working on his A500+ they were revision 8 motherboards. It might need something extra to get it to work.

[Tenacious]

The guy had it working on his A500+ they were revision 8 motherboards. It might need something extra to get it to work.

Bad ram chip?  You could try cleaning the board edge connections with an eraser, alcohol, etc.

[Dr. Chef]

I'll try cleaning it.

Edit: I've tried alcohol and yellow screen.

Thanks for the suggestions. I don't know what else to do. If in the end I cant fix it, then I'll see if Amibay has a replacement that I can purchase.

[motrucker]

The guy had it working on his A500+ they were revision 8 motherboards. It might need something extra to get it to work.

If yours is a regular A500, and it worked in a A500+ then the card is just mapped wrong (or your mobo is) . It's looking for the wrong type/amount of RAM?

[Bigcords]

For other future cases like this, I've been struggling with a similar issue for a long time - known working trapdoor memory expansion not being recognised - so stuck on 512kb. First i had grey screen on boot. I removed a jumper on my expansion to configure as chipram and got yellow screen on boot. I noticed that the rev5 motherboard had been modified...jp2 jumper had been soldered such that the top 2 pads had been joined and the trace to the bottom pad (originally joined to the middle one) had been cut. This seemed like a previous mod to set an expansion to chip ram. However, i read that i needed an agnus 8372 - and the board had an 8731. I guesses that had been sold and replaced with an 8371. I restored the original jo2 jumper setting - but still yellow screen on boot. So i spent an hour after finding various threads including this looking for a trace that had been cut. I noticed a bad sder joint on one of the trapdoor expansion pins underneath the board. I soldered it - and voila - the memory was accepted - working fine. I think the mod on my board was to remove solder on one of the trapdoor pins underneath the board. Hope this helps someone