Nvidia geforce 4 ti4600 repair

[opualuan]

I am working through issues on one of these ti4600 mac cards. It boots, but rarely gets to a mac desktop. The one time it was stable enough, I switched to 256 colors and had a lot of randomized noise on the screen. Only the dvi port works, nothing out adc.

There are a few missing caps as well as a 5-pin component marked “cer” (voltage regulator?) wired to a sil166ct4 (dvi driver?). I can’t find component values list for this card or even a datasheet for the silicon image part to troubleshoot. Any ideas or experience anyone can lend?

 

[GRudolf94]

Your obliterated U817 is probably a 74**1G08 AND gate. Need to see exactly where would the caps you're missing go to hazard a guess.

 

[Phipli]

Truth be told, it looks like U817 was never fitted, and you're just missing R306?

Edit - looking again, the U817 pads look torn up. It's confusing, given the R306 pads look used. How could both be fitted? They occupy the same space?

One must sit on the other. Anyhow... you're missing two components it seems (and 5 pads that will make the repair a little more tricky).

 

[CircuitBored]

This is the clearest photo of my Ti 4600 that I had to hand. Hopefully it's of some small use. I can at least confirm that there should indeed be another TSOP-5 at U817.

If needed, I can take some better quality macro photos. The image above was taken in 2015 on a contemporary smartphone.

 

[macuserman]

I have a dead, TI 4600 mac edition, believe it suffered from the typical fate of having the crappy OEM fan fail and then cooked itself. No visible damage though, if you want it for reference or to steal parts off of, I'll be willing to let it go relatively cheap, I intended to try to fix it but that is unlikely to happen these days.

 

[alectrona2988]

Dang, at least I'm not alone. Several years ago I once had a Ti4600 that I got from a local city dump and that died within minutes because the fan locked up. Wish I held onto it, now they're absolutely painful to get ahold of now because people sell them for absolutely unreasonable prices!

 

[GRudolf94]

Edit - looking again, the U817 pads look torn up. It's confusing, given the R306 pads look used. How could both be fitted? They occupy the same space?

Both sets of pads received solder paste, but only U817 got fitted, squishing the paste on R306. When the board got reflowed, the paste on the R306 pads conformed to the body of U817.

 

[opualuan]

Thanks all for your tips. grudolf94 I looked up a component reference and it seems likely this is a TI variant of the gate you mentioned. Sot23 or sc70?

 

[GRudolf94]

Thanks all for your tips. grudolf94 I looked up a component reference and it seems likely this is a TI variant of the gate you mentioned. Sot23 or sc70?

That's too small to be SOT-23, so I'd be inclined to say SC-70/SOT-353 or whatever. You'll still need to do a bit of bodging as the pads are gone.