Help identifing broken chip on Quadro 1100fx pcb

[MinorTthreat]

Hi! First post here ever!
I need some help. I have a Quadro Fx 1100 AGP and a small part is broken on it. The card is the same core and layout as the 5700 Ultra (NV36 maybe?). It has a small part/chip broken on it, it is on the underside of the card near the DVI out. The part has three legs/pins two on one side and one in the middle of the opposite side. It is surface mount and very small. The only marings are "A7p" with a small "33" turned sideways from the other markings. I have decent solder skills and could fix it but my knowledge of electronic parts is almost nothing... that sounds like a sketchy combination I know, lol! Thanks for any replies!here is a PIC

 

[Mark R]

Probably a 3.3V voltage regulator (SOT23 size) - a standard part available from any electronics supplier for a few cents.

 

[MinorTthreat]

Originally posted by: Mark R
Probably a 3.3V voltage regulator (SOT23 size) - a standard part available from any electronics supplier for a few cents.

Awesome! Thanks so much! I found some at At Mouser.com. Is this what you mean?

 

[TanisHalfElven]

a more deatiled pic. (high res) would help.

 

[TheRyuu]

Originally posted by: tanishalfelven
a more deatiled pic. (high res) would help.

:thumbsup: That pic is way to small to really tell anything.

 

[MinorTthreat]

PIC

PIC2

Sorry the first picture was so small. It took some patience and a magnifying glass to get these picyures. Thanks again for the replies.

 

[Mark R]

OK. We have a positive match.

It's a BAV99 diode pair.

 

[MinorTthreat]

Originally posted by: Mark R
OK. We have a positive match.

It's a BAV99 diode pair.

Thanks! I am looking at THIS PAGE @ MOUSER and I am still a little confused as to which one I should buy or how to tell. Thanks for the help, I am lost!


EDIT: I am thinking THIS ONE since you said pair and this is listed as dual?

 

[Mark R]

Originally posted by: MinorTthreat

Thanks! I am looking at THIS PAGE @ MOUSER and I am still a little confused as to which one I should buy or how to tell. Thanks for the help, I am lost!

Any one of those should do, as the BAV99 is a standard part available from many different manufacturers. They should all have equivalent performance.

It's a bit confusing that Mouser lists the same part multiple times though (e.g. the 512-BAV99 and the 512-BAV99D87Z) - They're the same part; the only difference is that D87Z means that they come from the factory in packs of 10,000 whereas they normally come in packs of 3,000.

 

[MinorTthreat]

So the A7 means it is a Fairchild part then. Is it a very common part? I have tons of old PCI and ISA cards to get parts from but none of the parts that look like that (sot-23) have an A7 on them that I have seen. Is there another way to tell by visual inspection? I can easily order the part but if I take one off an old card I could save some time. Thanks

 

[Mark R]

So the A7 means it is a Fairchild part then.

No. A7 in conjunction with a SOT-23 package means BAV99. This does seem to be a standard marking amonst manufacturers. This intrigued me too - in fact I think the A7p actually means the original is a philips part (the 'p' is philip's code for 'Made in Hong Kong').

Chances are that if it doesn't say A7 it probably isn't the same part - that doesn't mean it definitley won't be compatible, but there seems to be absolutely no logic to the markings.

Before you actually do try and repair the card, do you know why the diodes fried in the first place? Could a malfunction somewhere else have burned it?

 

[MinorTthreat]

It looks like it was broken in half like it was hit or dropped. I couldn't see any burn marks. I ordered a couple from Mouser they are only $.10 but I will still look at my old parts and hope to find one before it gets here.

 

[MinorTthreat]

Thanks a bunch for your help! I tried installing the diode but no luck. Still dead. I tried to unsolder and install another one to see if I had a dry joint or a bad diode and pulled a small piece of the trace with it... I need more practice I guess. Thank again this forum and its members are the best!