A1200 IDE issue - burned my CF (literally)

[Amiga1992]

I have a friend's A1200 that was behaving erratically and I had pinned the problem down to the IDE being funny. Since it had a CF-IDE adapter there, and the card was read fine on my computer, I guessed the CF-IDE adapter or the IDE cable were faulty, which is usually the problem I expect when this happens.

So not having any other adapter around, I grabbed my main Amiga's CF-IDE adapter and its card (), popped it in the A1200, and nothing.
Put it back on my A600, and IDE LED is stuck, nothing happens. Panic mode on.

I take out the card, and it literally smells burned if I put my nose on the CD connector

So this A1200 is burning cards, now , I don't know how to proceed, or what could have happened here. I never encountered this problem before

My friend said he was having issues, and he changed the PSU and it seemed to be working again, but the internal drive wouldn't work. The accelerator seemed to be missing too, but my tests show it seems to be working.

The machine was recapped last March by Retropassion, so it can't be that.

Any idea what could be happening here? is there any chance the A1200 IDE is reversed to an A600 and I plugged it backwards? (don't think so). Could a faulty PSU have blown something that is now creating overvoltage on the IDE port? Is the CF-IDE adapter now also compromised or is it safe to still use?

I'm afraid of this 1200 now.

Regular reminder to back up your drives, I didn't have a recent backup of that card, so I lost a bunch of shit (but not too much)

[Amiga1992]

I just probed the power pins on the IDE header, and they read 4.90V
So I am very confused.

Wait, pin 44 reads 4.90V too. So maybe R971 blew
[edit] R971 measures 4.7 so I guess not. back to: confused.

[supaduper]

The Gayle chip handles IDE so check pins 13 and 14 ( _IDE_CS(1).._IDE_CS(2)), check you are getting a signal for primary drive active, I just had a dead IDE on a A600 and the Gayle chip had fried

[Amiga1992]

Originally Posted by supaduper

The Gayle chip handles IDE so check pins 13 and 14 ( _IDE_CS(1).._IDE_CS(2)), check you are getting a signal for primary drive active, I just had a dead IDE on a A600 and the Gayle chip had fried

Does that require me having a scope? Because I don't have one. I just have a multimeter.

Even if that was the problem, a dead Gary, why would it fry my CF? That seems weird. I never had an Amiga fry a CF

[supaduper]

I mention Gayle ( you said Gary) because you said the A1200 IDE does not work, you can check that there is a signal there with just a cheapo logic analyser that will show if there is a signal present, Amiga`s are weird they can fry anything PMSL, does the Gayle chip get hot ?

here is a video of me checking the CS signal on an A600 gayle, ignore the video quality my camera is C**p

https://mega.nz/file/ExR0AazK#M9NAZ1...7UaSygGxyG2oNg

[Amiga1992]

Originally Posted by supaduper

I mention Gayle ( you said Gary)

Sorry! My brain is a mush. I spent too much time trying to work on an A500 before this :P

you can check that there is a signal there with just a cheapo logic analyser that will show if there is a signal present

I will get one (I don't have one) and check. However that won't tell me if there's overvoltage. Could it fry the analyzer?

thanks so much bud (also hope you're well, it's been forever )

[Amiga1992]

Originally Posted by supaduper

I mention Gayle ( you said Gary) because you said the A1200 IDE does not work, you can check that there is a signal there with just a cheapo logic analyser that will show if there is a signal present, Amiga`s are weird they can fry anything PMSL, does the Gayle chip get hot ?

I got my logic analyzer! But where do I plug it? 5V?
I really have no idea what I'm supposed to do with this .
Am I supposed to have something in the IDE port? It burned the previous card, I don't really want to plug anything to it and risk burning it.

[supaduper]

You can get the 5v from the floppy port it is the left most pin, to check if you have IDE signals working go to the Gayle chip(U5) and probe pin 13 (_IDE_CS(1) ) and see if you have a pulse signal on power up

[Amiga1992]

Originally Posted by supaduper

You can get the 5v from the floppy port it is the left most pin, to check if you have IDE signals working go to the Gayle chip(U5) and probe pin 13 (_IDE_CS(1) ) and see if you have a pulse signal on power up

OK thanks boss, I will try this on the weekend!
I'm also waiting on some diagroms

[Amiga1992]

Originally Posted by supaduper

You can get the 5v from the floppy port it is the left most pin, to check if you have IDE signals working go to the Gayle chip(U5) and probe pin 13 (_IDE_CS(1) ) and see if you have a pulse signal on power up

I just tried this and I have no idea what I am looking for. Results:

On powerup, probing pin 13 on Gayle, makes the analyzer show HI, a click/beeping sound and the round light blinking ("Logic 1 with negative single pulses"). When the Kickstart screen shows, the light stops blinking, the beep becomes constant (instead of interrupted), and the HI light remains on ("Logic 1, no pulse activity").

Now what?
Gayle does not get hot.

[supaduper]

So that looks like you have the IDE_CS signal present on GAYLE so that is good and gayle does not get hot anyway , now go to the IDE 44 pin header and see that the IDE_CS signal is geting to pin 37 on the IDE header if it is then obvs you need more diagnosis

[Amiga1992]

Originally Posted by supaduper

So that looks like you have the IDE_CS signal present on GAYLE so that is good and gayle does not get hot anyway , now go to the IDE 44 pin header and see that the IDE_CS signal is geting to pin 37 on the IDE header if it is then obvs you need more diagnosis

I tried with the multimeter and there is a connection, did not try with the logic probe.

I'm stumped. I don't feel like burning another CF and /or adapter, maybe it was just the adapter being bad? I really don't know. But this worked for a while...
I'm waiting on some Diagroms, would that maybe shed some more light? This is very strange. The machine is otherwise operating normally as far as I could test.

[edit] I also noticed a homemade-looking fix underneath the mothearboard, C222 has been replaced by a thru-hole ceramic capacitor, not sure if this is related, because that seems to go to the video decoder chip. Here's a pic:

[supaduper]

Yes wait till you get the diagroms and do a full scan with it, also yes it could have just been a bad CF adapter and also I have known CF cards to go bad too so I would just get hold of a new CF adapter or try a old 2 1/2 inch harddrive if you have one lying around,
should not matter about that ceramic capacitor but just check it with a mulitimeter to see it has not shorted

[Amiga1992]

Originally Posted by supaduper

try a old 2 1/2 inch harddrive if you have one lying around,
should not matter about that ceramic capacitor but just check it with a mulitimeter to see it has not shorted

I do have a 2.5"drive around, but I fear burning it too. Possible?
Meanwhile, I should get another CF adapter and card indeed. I have an SD adapter but I don't want to possibly waste it.

I checked the cap and it isn't shorted.

[Amiga1992]

Originally Posted by supaduper

Yes wait till you get the diagroms and do a full scan with it, also yes it could have just been a bad CF adapter and also I have known CF cards to go bad too so I would just get hold of a new CF adapter or try a old 2 1/2 inch harddrive if you have one lying around,

Welp I got diagroms, I did a full scan and there are no problems. but the Gayle test will not do anything without anything attached to it, and I thought I had an old 2.5" drive around, but I don't.

I guess it's time I buy another CF adapter and CF card and see if it blows up again. This is so weird. Could a bad power supply had blown up the CF/CF adapter? Because there was a bad power supply involved before.

[Amiga1992]

Well it seems I'm dealing with a pyromaniac A1200 here

I got a new CF adapter and card, and it all worked great! I was really chuffed. Then I went to build it completely, putting the floppy drive back in, and I try to boot it up and nothing was happening and then I smell/see smoke and want to die... turn it off ASAP and realize it's the floppy drive power cable's 5V cable. But how??? It cannot be plugged backwards, and all the voltages are read correctly, after the fact I read them again and they are fine (12.06V and 4.85V), and the machine seems to be happy working as it should, except that now I dont know what happened to the floppy drive.

Any ideas here? I never seen a floppy power cable burn up.

[jotd]

check if there's a short in the floppy cable maybe.easy to do with a multimeter in ohm mode

[Amiga1992]

Originally Posted by jotd

check if there's a short in the floppy cable maybe.easy to do with a multimeter in ohm mode

Well the cable is now all well burned so I wouldn't trust a reading. For what it's worth, it's not shorted now still, and neither is the power connector at the floppy drive

[supaduper]

Well it was Halloween yesterday , perhaps your A1200 is possessed lol

Joking apart you are having some grief with that miggy

[Jope]

Do you still have the plastic between the motherboard and the bottom shield? Is everything clear between the floppy drive and bottom shield when assembling the machine?