Cracked chip on 8.24.GC Nubus card.

[crazyben]

I recently won this in an auction. Seller described as fully working. I plugged to check if it works and it doesn’t. After upon closer inspection I noticed that the there is one cracked chip. Is this common chip that I can replace from another nubus video card?

 

[halkyardo]

That chip looks to be a resistor-capacitor network of some sort rather than a logic IC, probably providing termination for a bus or something rather than a logic function.

It would be trivial to identify a replacement part (or even fabricate an equivalent from scratch), if its properties are known, but a quick search doesn't seem to yield any useful datasheets.

It's quite possible that the card will still function OK in that state, I'd recommend just cautiously trying it out as it is.

 

[crazyben]

I tested the card and it is not working. No video.

 

[Garrett B]

C6 looks a little funky... I'd check it out to make sure it isn't shorted. Wouldn't want to have anything blow up the first time you try things out.

 

[crazyben]

C6 looks a little funky... I'd check it out to make sure it isn't shorted. Wouldn't want to have anything blow up the first time you try things out.

Wow good catch I totally missed. I will replace it right away.

 

[MindWalker]

Quite a bit of mechanical stresses on the board; a hit mark on the oscillator next to the broken chip, one of the RAM chips is wonky (top-right in second photo) and at least two pins slightly bent on the chip marked RNDC (top-left). Shipping damage?

 

[mg.man]

Quite a bit of mechanical stresses on the board

Spotted these as well :

 

[crazyben]

Spotted these as well :
View attachment 73437View attachment 73438

These were all damaged prior to shipping. I fixed the bent legs on chips. And removed the C6 cap and now it works.

 

[mg.man]

...and now it works.

Well done! Congrats.

 

[crazyben]

Well done! Congrats.

Thank you. Now I need to find out why this card is so desirable lol.

 

[Iesca]

If that resistor network IC stops functioning, the ones found in old compact macs were recently reverse engineered, so we know that it can be done if needed (assuming you can't find a donor board).

 

[crazyben]

If that resistor network IC stops functioning, the ones found in old compact macs were recently reverse engineered, so we know that it can be done if needed (assuming you can't find a donor board).

That’s good to hear. Hopefully it will stay put