Caps on QDI MOBO

[Gianni]

I posted a question here and I'm back with more questions: I received yesterday a PC that began to have problems.
Sometimes it start correctly and most of time it doesn't POST at all; when this happen very often it emits BEEP as RAM was missing.
I tried different memory bank but the MOBO behaviour it is not costant: sometime it BEEPS sometime it stays silent even if CPU FAN is running but very seldom it POST.

I can't identify the BRAND caps around CPU, they are aluminum without sleeve with HD W4 text on top; they look good OK.
There 10 small caps, 1000uF 6.3V, spread on the board, they are green with a gold logo; I suspect these are not good and part of the problem. I can't identify the brand.

There are 2 Fujicon 470uF 10V, they look good.

What I would like to try is to connect good caps in parallel to the 1000uF 6.3V and see if the problem is there.

About PSU: it is an Alied , it has been changed not long ago and it looks still OK but I will test the MOBO with a better PSU.

Here few pics of the MOBO (Kinetiz 7E-A VIA).

Ciao
Gianni

[momaka]

Re: Caps on QDI MOBO

The sleevless caps with HD on top are Nichicon HD. I don't think those had any problems like the HM/HN, so they should be good (but you never know what that Allied PSU could have done to them).

As for the green caps - I've never seen their logo before so I don't really know anything about their quality. They do seem suspicious, though.

You can try and add caps in the empty spots in VRM, but I doubt the problem is with the Nichicon HD caps. I'd say the green caps are crap and need replacing, but like I said, I've never seen them before so I wouldn't know what their quality is like. They are around the ram slots, so that could explain the weird beeping as if memory was not present.

[Gianni]

Re: Caps on QDI MOBO

Hi momaka

I followed your suggestion and this afternoon I replaced the green caps and the 2 Fujicon, here attached some pics.

I replaced the 1000uF 6.3V (green caps) with 1000uF 10V Panasonic FM and since I had not enough pieces I used one 1000µ 16V; for the Fujicon I had not FM caps so I mounted Rubycon YXF caps.
I didn't try to place the caps in parallel because it is not esy to solder them, the solder points are not big.
The logo on green caps is DST , I will test them on Monday in my office.

As I wrote before, I don't know what happen to this PC, probably someone tried to fix it with an hammer... just look to the cabinet pictures attached here.

Right now I'm updating windows and I want to run some test and I hope everything will be all right otherwise next step is to replace all HD caps.

Ciao
Gianni

[momaka]

Re: Caps on QDI MOBO

Maybe the guy didn't use a hammer. Maybe he just hit it very gently, but the case was crap and it just crunched . After all, isn't this the Deer/Allied/L&C case that came with the Allied PSU?
I have a few cases like those as well and they seem to be made of very cheap steel. A beer can is easliy stronger. Hopefully the motherboard hasn't been damaged by that case.

I also did a quick research on the DST caps. Both capacitorlab and this website list them as bad. Same with the Fujicon caps. From what I noticed on different threads here, they seem to be very common for QDI boards too.