How to determine if Buster is failing

[efrenmgp]

Hello!

I have an A4000T that refuses to "see" a Picasso IV board. It does not show in the early startup and the p4flashupdate program cannot find it either, no matter which slot it is in.

Dragster and I spent several hours testing everything we could think of. We also tried a Deneb card and even when that one is seen by the early startup, the boot animation does not show at all. Both cards (Picasso IV and Deneb) are happily working in an A4000D so we know they are OK, and the Deneb animation plays everytime it is turned on. Also the Picasso IV board was reflashed to the latest 7.5 using the A4000D.

After lots of testing & swapping processor boards, adding and removing additional components such as hard drive, floppy, memory, etc we always got the same results.

We are suspecting the Buster chip may be the one to blame... but we don't know what test to do to know it for sure (maybe we already proved it?)

Does anyone has had a similar experience? Is there some diagnostics software that can be used? Any advice and/or shared experience will be most welcome

Thanks!
efrenmgp

[matthey]

I have a similar problem on a 4000T. All the boards show up on power up but the boards will disappear on a reboot after the machine is warm enough. I replaced the Buster 9 with a Buster 11 and replaced the power supply but it does the same thing. I did notice that my Buster socket is warped. It bulges in the middle of 3 sides. I plan on getting a new one soldered in and the caps done (minor leaking just starting) to see if it fixes it but haven't got around to it yet. The 4000T (and 4000) look like the Buster socket is cheaper than the 3000(T) sockets.

[efrenmgp]

I did notice that my Buster socket is warped. It bulges in the middle of 3 sides. I plan on getting a new one soldered in and the caps done (minor leaking just starting) to see if it fixes it but haven't got around to it yet. The 4000T (and 4000) look like the Buster socket is cheaper than the 3000(T) sockets.

The one I have here has the Buster soldered and we were considering getting a socket so we could switch busters and test... but it would be an expensive test

About caps, we didn't consider that because everything looks completely clean but those are not too expensive and I guess it's better to change them sooner than later anyway.

Regards,
efrenmgp

[Jose]

I had that happen with my PIV with all latest chips/firmware and with an A4000T too, but it was the other way around. The 4000T would see the card, my 4000D would not. I tried everything and pretty frustrating it is swaping cards all around. I wasn't even gonna bother but decided to get another daughterboard for the A4000D that was going cheap on eBay. It worked! Even regretted after buying it thinking it would make no difference but that was it. I'd say change the caps but it might not do any difference. Maybe it's just some electrical compatibility with some boards, the daughterboard that was failing was in pristine condition, looked all new and shinny, much better than the one that worked! It even worked flawlessly with an A4091 and a Cybervision64 at the same time, and we all know those are pretty demanding of the ZIII bus.
I did notice that they had different chips on them (daughterboards on A4000D have 2 chips), so maybe try identifying the equivalent chips on the A4000T (if they exist) and replace them, if changing caps doesn't work.

[efrenmgp]

I did notice that they had different chips on them (daughterboards on A4000D have 2 chips), so maybe try identifying the equivalent chips on the A4000T (if they exist) and replace them, if changing caps doesn't work.

Thanks Jose! I'll take a look at those chips and see if I can find their counterparts on the A4000T. But depending on how small they are maybe I won't dare changing them myself :eek:

Regards,
efrenmgp

[Dragster]

Hmmm I wonder if there's any software tool to perform the buster chip test... wondering if the good old advanced amiga analyzer could do the job...

[matthey]

Hmmm I wonder if there's any software tool to perform the buster chip test... wondering if the good old advanced amiga analyzer could do the job...

I've used the Amiga Analyzer from Australia and it didn't have a Buster test. I don't know anything that does.

I forgot to mentioned that my 4000T is unusual in that it has a socket for the Buster. It's an early revision motherboard that's yellow instead of green. Most have soldered Buster 11. The grounding points and connections to the motherboard should be cleaned if not already. Maybe this could be a grounding problem? Some of the 4000T main power connectors to the motherboard have arced and have black carbon. It might be worth pulling the power connector and looking. Mine had minor arcing carbon. I replaced the AT power supply with one from newegg but it didn't fix the Zorro slot problems. Problems like these probably aren't always the same.

[efrenmgp]

The grounding points and connections to the motherboard should be cleaned if not already. Maybe this could be a grounding problem? Some of the 4000T main power connectors to the motherboard have arched and have black carbon. It might be worth pulling the power connector and looking. Mine had minor arching carbon. I replaced the AT power supply with one from newegg but it didn't fix the Zorro slot problems. Problems like these probably aren't always the same.

Hello matthey!

We did check the power connectors and they are all nice and clean, however we didn't verify voltages... I'll do that and see if everything is as it should be. (I kind of hope it isn't) :laugh1:

Thanks!
efrenmgp