Troubleshooting a PowerPC card?

[eharmon]

I stuffed a known-working (at least, before now) Apple PowerPC PDS card into my Quadra 650 and it doesn't seem to be working. I've done all the usual:

1) There was slight corrosion on the socket and card, I cleaned with isopropyl and hit it with de-oxit and re-seated everything.
2) I checked the voltages on the rails, they're solid at just over 5v and 12v. I haven't checked -12v but I figured it was unlikely the card uses it.
3) I removed the card and checked the system still boots properly without the card -- starts up every time just fine.
4) I removed the other Nubus cards.
5) I visually inspected the board, I don't see any cracked solder joints or damaged components and, as above, it worked fine pretty recently in another board, as far as I know.
6) I checked for heat, VR1 gets warm (but not crazy hot) which seems expected, and the processor itself seems like it's generating a bit of heat (but nothing crazy -- just slightly above ambient temperature).

But no chime at all. I get a speaker pop as the power comes on and the LEDs light up, but it never seems to go beyond that. No boot, no crash, nothing.

Has anyone experienced these symptoms before? No documentation I can find is useful, it's all basically "reseat the card".

 

[3lectr1cPPC]

Photo of your board?

 

[joshc]

The 601 could be cracked, or the legs of the 601 could have bad solder joints and need reflowing. Unfortunately the 601 is very fragile, and also run very hot, both factors that could cause either a cracked CPU or bad solder joints.

 

[eharmon]

I'll grab a photo with the heat sink removed tomorrow.

CPU looks pristine though to my eyes. No cracks, and the legs look alright.

 

[Phipli]

I'd deoxit the card and slot again and insert remove the card a few times. Also make sure it is absolutely plugged in all the way.

 

[eharmon]

Hit it with another round of de-oxit, still no dice.

I inspected the entire board again, the only concerning thing I see is some cruft around the back of the connector, but the pins and leads themselves don't show any sign of damage.

My only guess before crawling over the board with a scope is a vinegar bath and a second alcohol wash on the connector?

 

[Phipli]

Hit it with another round of de-oxit, still no dice.

I inspected the entire board again, the only concerning thing I see is some cruft around the back of the connector, but the pins and leads themselves don't show any sign of damage.

My only guess before crawling over the board with a scope is a vinegar bath and a second alcohol wash on the connector?

Your 650 isn't overclocked is it?

 

[eharmon]

Nah, I clocked it back down to stock to test this card.

 

[Phipli]

Nah, I clocked it back down to stock to test this card.

Its an 80MHz grade chip anyway, so probably will take a huge overclock if you get it running.

 

[dramirez]

were you able to fix it eharmon?

 

[eharmon]

Not yet. Been distracted with some other things and I need to get the scope on it to see why it's not running. The chips get warm so it's doing something anyway...