Epox EP-8RDA+

[Doc]

Re: Epox EP-8RDA+

In the process of taking a close look at all the caps on the board to make the list above I ran across a capacitor that I could hardly read. Turns out it was baked so bad that it was almost black. Against the advice I got from you guys, I replaced it with another of the caps from the old K6 board and Viola! Perfect working computer (so far).

I'm installing windows xp media center on it right now so we'll see if I screwed anything up. USB doesn't seem to be working, may be a driver issue.

There are still 4 Noticeably bad caps left on the board that I need to replace (the 2200uf 10v GSCs). I'm going to try to find those locally so I dont have to spend as much on shipping as the caps.

I feel pretty good about actually being able to repair a motherboard though, even if I did go the Po-Boy route and haven't spent a dime on it so far. Couldnt have done it without this site though. =)

Doc

[davmax]

Re: Epox EP-8RDA+

Thats encouraging progress. Those 2200u caps are at the input to the VRM, failure could suggest higher than normal ripple from power supply. Have you checked the PS yet?

[Doc]

Re: Epox EP-8RDA+

Its running on a different PS from when it went bad. I will be looking into the PS sometime soon though to do a checkup.

Doc

Also, I'm not positive, but I think I've determined the cap that causes the hang at C1 while trying to post. If anyone's interested in this feel free to contact me.

[Doc]

Re: Epox EP-8RDA+

Gotta love it.

Sorry for the troubles. We can issue you rma repair,
Your RMA number is 3060123982

Please return your motherboard only to:

Epox International Inc.
Attn. RMA Department (with your RMA number outside the box) without rma number outside box our department will refuse the package.
531 E. Jamie Ave
La Habra, CA 90631

Instruction:
1. Please ship motherboard only and please pack well to prevent shipping damage.
2. Please include a note with your return mailing address, description of problem and the best number to contact you.
Without these information's your rma maybe delayed.
3. Please ship with UPS, Fedex, or USPS with tracking number.
4. Processing time is about 1 week, and board will be returned via UPS Ground.

[Per Hansson]

Re: Epox EP-8RDA+

Doc; please post a pic of that cap you talk about...

I only changed the "big" caps on my Epox board... It's working fine but I might think twice about selling it if the smaller caps go bad too...

[Newbie2]

Re: Epox EP-8RDA+

Doc is in the USA, he should get caps from Topcat.

[davmax]

Re: Epox EP-8RDA+

Re the toasted cap. Have you checked the supply voltages in the hardware monitor section of the bios? The cap may have overloaded a voltage regulator.

[Doc]

Re: Epox EP-8RDA+

All the voltages, before, and after the half-assed recap I did were very close to where they were supposed to be.

[Doc]

Re: Epox EP-8RDA+

Doc; please post a pic of that cap you talk about...

I only changed the "big" caps on my Epox board... It's working fine but I might think twice about selling it if the smaller caps go bad too...

The cap that finally did the trick was a 1000uf 6.3v cap. I marked it best I could in this picture.



It looks like even in this picture it's a bit of a darker color than its sisters. This isnt an actual picture of my board, but I bet you this guys' has been cooking too.

[PeteS in CA]

Re: Epox EP-8RDA+

The reason it could post 5 times in a row and then later not at all is because when the caps become warmer they actually work better ...

When lytics are hot, their capacitance is much higher, and their impedance is lower. For example, a 1000uF, 50V FM I've been torturing:

At 77C case - 961uF, 11.6 milliohms;

At 21C case - 879uF, 16.1 milliohms.

[Per Hansson]

Re: Epox EP-8RDA+

Cool Petes, I guess that test prooves that it is not really that important what farad rating the replacement cap has, as long as it's not crazily off. Since the circuit is prolly designed with quite a bit of tolerance in mind..

That is contrary to what most people say I mean...

And Dood; thnx, I thought you meant the smaller 470uF and below caps... I have already changed all big caps on my Epox, i.e. 1000uF and up... (since they where all bulging LOL)

[PeteS in CA]

Re: Epox EP-8RDA+

Lytics are +/-20% components - that is the significance of the "(M)" on Nichicon HN(M), etc. Cores used for filter inductors are usually +/-20% or +/-30% tolerance parts. So, yeah, compensation in regulators is designed to accomodate these loose tolerances.