A500 Won't Recognize 3.1 ROM

[Oldsmobile_Mike]

Can't read your screenshot.

So what you're saying is:

- The ROM works fine in other A500's.
- The Amiga works fine with other 3.1 ROM's.

That seems weird, so the only compatibility issue is between that particular A500 and that particular ROM?  You burned it yourself?  Stock, no changes?


Edit:  maybe I mis-read your post.  Are you saying the A500 won't work with any of the 3.1 ROM's you've burned?  I hate to say it, but have you tried one from AmigaKit?  You can buy one new for under $20 USD.  Easy way to troubleshoot is to test with a new one.  

[Oldsmobile_Mike]

http://en.wikipedia.org/wiki/Power-on_self-test#Amiga_keyboard_LED_error_signals

[Oldsmobile_Mike]

Check and re-check the socket?  And check it again, just for good measure?    Another dumb question - you're plugging it right into the motherboard, right?  Not using any kind of ROM switcher?

[Oldsmobile_Mike]

1.3 is 256K.  3.1 is 512K.  Some kind of addressing issue?  Any weird memory expansions in the system?

[Oldsmobile_Mike]

It's almost as if it's not bank switching, but only reading part of the ROM data. The incomplete startup menu is really strange.

That's what I was getting at.  I cannot for the life of me remember why you need to do that mod on Rev 5 boards.  Hypothetically speaking, if someone had plugged in a straight 3.1 ROM without doing the mod, is it possible that something on your particular board could have been damaged in such a way that only the older ROM would still work?

But I'd go back to checking the continuity, first.  

[Oldsmobile_Mike]

^^^  That is some danged amazing troubleshooting, there.  Not sure if Rev 8A is comparable to his Rev. 5, but couldn't hurt to inspect if those components exist.  You sir, win the dancing banana award for the day!  :banana:

[Oldsmobile_Mike]

I couldn't figure out this revision 5 A500, so I picked up a revision 6A A500 from a local electronics junk store today.

I'm impressed that they have "local electronics junk stores" in Texas that have Amiga parts!!!

I've got tickets to a tech event down there in Austin in September, anyplace you can recommend?

...btw, ripping my A500 apart in a few weeks for some upgrades.  It's a 6A, if you can't find those values before then I might be able to get them for you.  Not anxious about removing my VXL*30 though, haha.