Circuit board is missing a part

[Parlaan]

I picked up a graphics card. I have one just like it. The one I bought wasn't working properly, so I started examining it. It is missing a IC.

How can I find out what this is so I can replace it ?

[jsog]

Re: Circuit board is missing a part

It's a surface-mount capacitor. The problem is that there's no value code on it. If you can find the value, maybe by unsoldering the working one and measuring it, then it's easy enough to find a replacement. A through-hole ceramic cap could be soldered to the surface-mount pads, too.

The broken cap might not be the only problem with the board.

[momaka]

Re: Circuit board is missing a part

Yup, that's a surface mount ceramic capacitor. You can tell by the "C" prefix in its label, C864 (C is for capacitor, L is induction, R is resistor, Q is transistor, D is diode, IC or U is integrated circuit).

Where can you get one?? - from other junk electronics. That's where I get mine. All you need to do is just match the physical size of the replacement capacitor to that of the old one and it should work fine. I've done it successfully a few times now.

[ipman]

Re: Circuit board is missing a part

Looks like a ceramic decoupling capacitor. It's near an IC? Trace the continuity of the pad to the IC's legs to be sure.

[Agent24]

Re: Circuit board is missing a part

Where can you get one?? - from other junk electronics. That's where I get mine. All you need to do is just match the physical size of the replacement capacitor to that of the old one and it should work fine. I've done it successfully a few times now.

Heh, I've done that too, with a hard drive.

Funny thing though it worked just fine with the capacitors missing and also with the new ones I scavenged off a dead hard drive of similar model...

although with new ones on, it makes me feel better

[momaka]

Re: Circuit board is missing a part

Heh, I've done that too, with a hard drive.

Funny thing though it worked just fine with the capacitors missing and also with the new ones I scavenged off a dead hard drive of similar model...

although with new ones on, it makes me feel better

Well, in one of my cases, the missing capacitor was part of the negative charge pump on the T-Con of a LCD monitor. There's no way the circuit would have worked without that ceramic cap, even though it was just a tiny "sand grain". The original cap was shorted. I changed it and brought a nice 19" HP wide screen back to life (I have a thread here about it somewhere too).