VOGONS


First post, by Turbo ->

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I'm trying to repair Diamond Monster 3D (3Dfx Voodoo 1) PCI card. There are two SMD capacitors that need replacement (C55, C119). Does anyone have an idea what value should the capacitors be?

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Reply 1 of 4, by Doornkaat

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There are at least five revisions of that card. What revision do you have?
Judging from the PCB photo you posted C55 should be identical to C69. C119 should be equal to C117.
If you have a multimeter you can desolder those and find out yourself.
If I was to take a guess I'd say 2.2nF 16V.

Good luck! 😀

Reply 2 of 4, by Turbo ->

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It is a "B" revison, at least that is what is written on the card. If I desolder the nearby capacitor I will most probably destroy it, since I don't have a hot air desolding station, just plain soldering station. I don't know if it is the best idea to measure capacitance on circuit. C69 on circuit is 128uF, and C117 is 240uF which I belive it is way too much and should be desoldered for the correct measurement.

Reply 3 of 4, by derSammler

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Chances are that these are for decoupling only and their value is more or less unimportant. I have a Voodoo2 that had one capacitor torn off and I just soldered in the first one that fitted in size. The card works to this day without any issues.

Reply 4 of 4, by SSTV2

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Yep, those are simple bypass caps, you can easily tell that, because they are connected in parralell pairs, one (darker) must be 100nF, second (lighter) should be 10nF. Their absense is not critical for card's operation, but for a proper power itegrity/stability, bypass caps are a must.