Killed my A500?

[Liqourice]

So. Got myself a TF536 to replace my VXL-30.


Plugged it in after moving the 030 to the new board. Seemed to work fine except that it didn't want to work with the GVP HD8+ SCSI controller.


So, decided to upgrade the old 2.04 kickstart to 3.1 to see if that helped.


The damndest thing though, now the 500 seems completely dead, even after replacing the 2.04 kickstart and putting the 68000 back.


And yes, I made the connections between pin 1 and 31 as well as bending the 31 leg up and connecting to pin 21. Not sure if I made the best connections but I think they were enough.


Any suggestions as to what might have happened? When I flip the on switch I hear a crackle in the 1084 speaker, a quick klick from the floppy and the caps lock led lights up for a second but that's all that happens. Just a black screen and no power light or anytying else.

[Twisty]

If the powerlight didn't even light, it can be a problem coming from the power, have you try with another PSU ?

If you don't have another one, just check if all the voltage are correct (5v, 12v, -12v).

[Liqourice]

Nah, the PSU is a new Meanwell one. It shouldn't be damaged. I killed something on the board, most likely Agnus, Gary or both it seems. But, I'll check anyway just to make sure.

[Vypr]

Have you checked the solder joints on the power socket and the power filter? could have a cold joint there. Even if any of the chips are gubbed you should still get a power light.

[Liqourice]

Perhaps. Don't know really. Since I, in a moment of pure stupidity, made a major mistake and accidently fed 5V where it shouldn't go something might have overheated and lost connection.

This goes over my head though. I lack the knowledge and equipment to properly hunt for the fault and fix it so I'll probably send it away to someone who does.

[Liqourice]

Checked the PSU and it's perfectly fine so nothing wrong on that end.

[Liqourice]

After not touching this for a few years I now decided to try something else. Not sure why I didn't think of this before but it is what it is.

After ordering a new PSU and trying that made no difference I now swapped the CIAs and low and behold, it's showing life. Power light is on but nothing more happens. No click on the floppy, no activity if I put in a diskette.

No monitor connected ATM since my 1084 is in bad shape as well. Might hook it up just to see if I get anything to go by.

So, it seems I've managed to fry at least one of the CIAs, maybe both. Question is, where can I find those these days?

If I'm lucky I can source the chips from the "new" 500 I bought and I'm gonna pick up this weekend. Also a 1084S in that deal so might just wait until then but knowing myself that's gonna be hard now that it's at least showing some kind of life!

[jurassicman]

Original CIAs are available on eBay and are quite cheap, at least compared to Agnus, Denise, Paula and Gary IC...
Good luck with the repair!

[Liqourice]

It's something else. I reseated all socketed chips just to make sure there's good contact. No sign of corrosion or anything like that but now it's completely dead again.

I guess there's bad contact somewhere and I must have managed to make contact when I swapped the CIAs and then lost it again when doing the other chips. I can't see any broken solders with my bare eyes but I guess I have to go over the entire board and reflow every single solder point to see if that makes a difference.

Somewhat encouraging that I managed to get SOME life out if it after 4 years with only some minor touches. That should mean it's fixable.

[Liqourice]

Oh, and I did connect my 1084 and when it momentarily worked it booted up like it should, all the different gray screens and ending up on the kickstart screen requesting a floppy. Just that the drive didn't do anything.

Also connected my GVP HD8+ but that didn't boot either. Got a requester saying "gvpscsi.device: board 000 Ignored Status $FF/$FF"
Not sure what that means?

[Liqourice]

So, I got the "new" 500 and 1084S today.

Both work perfectly so far, tested a few disks and everything seems alright. End result is both good and bad, I was hoping for a rev 6a but it's a 5. The 6a is easier to deal with, upgrading chip ram and such, and it has Agnus 8372A, this rev 5 has 8371 so if my original rev 5 board isn't damaged (that it's only chips that's got fried) I'll use this as a spare. Case is broken in some places and looks generally nasty, keyboard as well.

So if I can't get my original board fixed with parts from this new one I'll just switch the boards and make the mods to that board instead.

A question though. When I put Agnus 8372A in my rev 5 board back in the early 90's the instructions told me to put a thin slip of plastic on pin 41. I've understood this is to make it PAL, is that correct? Need to know if I have to move it.

[Liqourice]

Ok. Moving over the CIAs didn't help with the floppy. Tried with the floppy from the "new" one that worked perfectly there and no go.

Also swapped Gary between them but still no go. What else could be the issue?

[Liqourice]

So, I've swapped all chips except for Denise and Agnus. Still behaving the same, just won't even try to read from the floppy. Tried the floppy drive in the other 500 and it works just fine there so it's not the drive.

What are the chances that my 8372A Agnus has been damaged? Seems my only choise right now is to move that to the "new" board along with the kickstart and hope that it works.

[Liqourice]

All chips swapped and still not getting anything from the floppy. It spins when inserting a disc but that's it. Not getting anything from my 1010 either and that also works just fine on the other board.

Ideas what can be wrong? All caps look ok, doesn't mean they are of course. Can't see any obvious burn marks on any solders or traces.

Sure, I got everything working with the "new" board and I've even made the 1MB chip mem mod on it. I can use this, it's working to 100%. I still want to fix my old board though, it's the one I bought new back in -88 so there's some kind of sentimentality around it.

[Elmo Putney]

Have you put a diagrom in it? See what that says?

[Liqourice]

I have no diagrom for it I'm afraid.

And until I get my A4000 assembled I have no way of creating a floppy with Amiga testkit either.

Might as well get a diagrom for it, gonna check where I can find one.

[Liqourice]

Got my GVP HD+ to boot as well finally. Not very stable though, get read errors so I guess the drive is starting to give up. Not gonna touch it until I get a 44 pin IDE cable so I can hook up a CF reader to my TF536 and make a backup of everything before it's to late. I've got a complete backup of my old BBS on it that I want to keep.