Amiga 4000d - Zorro Issue Advice

[Lamaman71]

Hi Folks,

Picked up a 4000d - main board works great, passes every test ive thrown at it. Very clean, minor battery damage.

Plug in the daughterboard - no issues until I plug in a Z3 IDE card or a Z2 SCSI card and the machine starts to exhibit issues.

Z2 and Z3 cards are recognized without problems in early boot and subsequently in SYSINFO.

Best example is using the Z3 IDE card with an IDE HDD (this applies to any HDD). The machine boots from the Z3 IDE card no problems at all. However, within a few minutes the Amiga starts to throw up bad block errors all over the place.

The drives Ive used all work fine on the internal IDE - so these arnt genuine HDD errors.

If I reboot, the machine will usually refuse to boot at all, or will GURU. However, turn it off, walk away and reboot 10 minutes later, the machine is back to normal. For a few minutes anyway. Rinse and repeat.

I wonder if anyone might have seen this behavior before? I wonder if its heat related - perhaps exposing a bad solder joint or failure in an IC?

[jbenam]

I had a bad Buster which gave me weird issues (mainly gurus) when using Zorro-related features.

Try with another Buster - if that fails, try replacing U714 (and maybe U701 as well? Can’t remember if that is Zorro related).

If that also fails, you might have a faulty 74Fxxx or micro solder cracks somewhere along the Buster lines.

To discount thermal issues, slap a giant fan over your Amiga motherboard and see if the timing changes (e.g.: issue happens after 20 minutes using a fan instead of 10). You can also do the opposite. Heat up the motherboard with a hairdryer and see if that triggers the error immediately. If both of these two things don’t make a difference, then it’s not a thermal issue. Might still be a partially faulty IC somewhere, though.

Good luck!

[cv643d]

Maybe you need the latest revision of Buster?

[Akiko]

I don't have exactly the same issue as you but similar, my A4000T recognises both ZII, ZIII in the early boot menu, but ZIII cards don't work, Deneb is not detected by Poseidon, ZIII graphics cards crash after driver initialisation, and the Elbox Fata ATA 4000 card puts the machine into a never ending boot loop.. All cards that can be put into ZII mode then work fine.

I haven't gotten around to getting mine serviced yet, but I was told by a good hardware repair engineer that it's most likely either faulty Buffer chip IC's, the Buster, or trace.

If you Google Zorro issues there seems to plenty of examples with varying possible underlining issues, it might be advisable to have someone look at it if you aren't experienced with repairs like me.

[Lamaman71]

Thanks folks. Buffer chips and a new Buster 11 on order. If, after that little lot, its not fixed Ill be looking for some professional help!

[Akiko]

Do please let us all know how you get on, sadly these types of threads more often than not have no final outcome.

[Lamaman71]

Will do. I have a word document Ive been maintaining as Ive made changes or adjustments - so Ill upload it later on as well. Between the Buffers, GAL's and Buster I hope one of those things will resolve it - everything is waiting on delivery though, so may be a while.

[Lamaman71]

Hi - sorry, yes, complete recap. PSU checked, its the original - voltages all look fine.

[nogginthenog]

Could it be something as simple as a MaxTransfer issue? What Kickstart are you running?

[Lamaman71]

3.2.2 kickstart

I’d have thought a max TRX issue would manifest itself from the outset rather than just progressively get work over the duration the Amiga is left switched on?