IIci dead Nubus slots

[beachycove]

I posted about this a few years back, but rather than resurrect a very old thread which didn't go very far, I will begin anew.

I received a IIci several years ago that came with dead Nubus slots. As it did not work, it got shelved for another day. Well, the day came last week, as I have been recapping some of my older machines of late, and thought that I would give this one a try and see if new capacitors fixed the problem. Alas, recapping the board did not fix the problem. The board has been thoroughly cleaned and has been dried.

The IIci's Nubus slots are getting power (a light on an ethernet card shows that), but no Nubus cards work and none are reported by utilities to be present in the slots. Drivers are present in software (7.1). I have confirmed this in another Iici.

The defective machine otherwise boots and seems to run just fine, oddly enough.

What is the most likely cause? I am assuming the big Nubus controller chip just south of the Nubus slots, or else one of the Bus Transceivers, making it unfeasible for me to try to repair the board (better soldering equipment required!). Could it be something simpler, and so repairable, or am I best to cut my losses and part out the machine? It has a working PS, a decent case, etc.

 

[olePigeon]

Did you also replace the large 470uf and 220uf polar capacitors?

 

[beachycove]

Yes.

 

[uniserver]

^ Yes, change the fat ones? Also check for corrosion bridges (I use a dental pick) on the IC's. the leeky cap ooze can cause some headaches.

I mean if its not that , then its quite possible a handler at one time, might have Discharged their static energy into a Nubus card and somehow blew the Nubus controller.

I've personally (ESD'd) blown the PCI controller in a south bridge of a 299.00 you are outta your mind dell specials, when installing a NIC Back some years ago.

it was a bad day, I ended up installing some ASUS something for the customer and OC'd the CELERON from the dead dell board to like 1.5ghz with a monster cooler… it acutely turned out quite nice.

 

[uniserver]

I have a IIci i got from captinbob, (the same guy that just sold a SE/30 for $710.00 on epay)

You can buy it from me if you want it, it's got a cache card in it from mcdermd, works good.

 

[beachycove]

check for corrosion bridges (I use a dental pick) on the IC's

There is a little corrosion here and there, but not much. I saw your mention of a dental pick in another thread, and so had already scraped at it with a pocket knife and then cleaned it up with alcohol, but you think that it might be worth going at it a little more thoroughly? I have seen similar things on a lot of old boards and this is the only one that doesn't work. But you know this stuff way better than me.

Is there is some chemical that would tackle corrosion (with a good wash afterward), or is a mechanical tool the only way to go?

 

[uniserver]

I'v found the best way is to take your time and scrape with a dental pick…

Unfortunately with these old Logic Boards you can get rather time invested,

To avoid depression I always avoid looking at the clock before/during/after I do a re-cap.

 

[tecneeq]

Don't be depressed, other people create models out of toothpicks. That is wasted time and depressing. Resurrecting a 68k Mac is not. |)

 

[James1095]

The light on the card tells you that there is power to the slot, but there are multiple power rails of different voltages, one or more could still be dead.