ECS-K7S5A/ PCCHIPS-M830LR with GLUXON = shite

[MD Willington]

Just last week, December 23, 2004, my K7S5A V1.x died. Upon further investigation I discovered the following:

!! BAD CAPS !!




I received an ECS K7SEM with the same "GLUXON" capacitors in the power section of the mainboard. So far the GLUXON brand capacitors have proven themselves to be hit or miss in quality. Hind sight is 20/20, I should have checked my K7S5A...so my loss is now your gain in knowledge.


As a result the power section of the board destroyed itself, the FET's are destroyed, pieces have literally exploded off of their packages. Catastrophic failure.





This is just a heads up to fellow K7S5A owners. If you mainboard has the GLUXON brand capacitors try to have them replaced by a competent technician.



MD

[larrymoencurly]

I have a K7S5A Pro and a P4S5A2 v. 1.0 with purple Elite brand caps in place of those G Luxons in the power section, but both mobos have lots of green-silver and black-white G Luxons elsewhere. Are these G Luxons prone to failing?

[MD Willington]

The lower value, under 1000 micro farad caps are considered to be okay...1000, 1500, 2200 are usually the junk ones...

Drop by the un-official K7S5A forum...
http://p199.ezboard.com/bk7s5amotherboardforum

MD

[MD Willington]

Got a freebee in the mail, another K7S5A with badcaps and a blon IRL3103S power mosfet...Oh the fun...

MD

[Fatal0E]

on the K7S5A pro, they used OST caps instead, not any better though.

[MD Willington]

Yep, I still have my pro...caps aren't bad...YET

MD

[MD Willington]

Re: ECS-K7S5A/ PCCHIPS-M830LR with GLUXON = shite

Another board in today, version 3...same poopy caps

[Rainbow]

Re: ECS-K7S5A/ PCCHIPS-M830LR with GLUXON = shite

I've repaired two of these damaged K7S5A boards.
The 3 mosfets were bad on both boards, they were so hot that they desoldered themselves from the board The 3 double-diodes were good. Some of the smaller caps around were destroyed from the heat.
There are 3 mosfets in that VRM, each has two small SMD transistors near its gate. Some of these transistors were also bad. The mosfets are connected parallel, only each gate is driven separately through that small SMDs but they're all driven by the same signal.
Repair:
Remove the big caps (and also the smaller ones near ATX connector and the one near KA7500B), remove fried mosfets. Then check if the double-diodes aren't shorted (there is some resistor connected across them, so they don't test like a diode). Then check the small SMD transistors - it can be tricky (and if you leave one bad there, the mosfets might short again). I used "diode test" on a multimeter - checked each direction on each transistor and compared to the other ones, then removed the suspicious ones and checked out of circuit. Replace bad ones, then replace the mosfets (I used better ones from dead Abit KT7A board) and recap.

I've read that some K7S6As fail exactly like this - but I haven't seen it personally yet (I've had only a working one). The circuit is a bit different - all mosfets are driven only by two transistors which are not SMD but TO92 (easier to replace).

[Rainbow]

Re: ECS-K7S5A/ PCCHIPS-M830LR with GLUXON = shite

Some photos - first 4 before repair, last 3 after.

[PeteS in CA]

Re: ECS-K7S5A/ PCCHIPS-M830LR with GLUXON = shite

I noticed you replaced the MOSFETs, too. The center one in the before pic had a piece missing from its case. I also noticed that you used Fairchild in place of IR. Is Fairchild a favorite or what you had available?

[Rainbow]

Re: ECS-K7S5A/ PCCHIPS-M830LR with GLUXON = shite

All three original mosfets were shorted and they desoldered themselves from the board I've downloaded the datasheet and compared the most important parameters (is logic level?, RDS(on), Id) with mosfets found on boards in my junk pile. The ones I used were from dead Abit KT7A board. They're better than original mosfets (lower RDS(on) -> less heat, higher Id). High quality mosfets like these can be expensive and hard-to-find - and I have a lot of irrepairable boards with them

[kc8adu]

Re: ECS-K7S5A/ PCCHIPS-M830LR with GLUXON = shite

i have a drawer full of salvaged mosfets,vrm chips,ect.
i take the junk boards out on the dock and heatgun the underside.
i pick up the parts with hemostats when the solder melts.

[cj_barry]

Re: ECS-K7S5A/ PCCHIPS-M830LR with GLUXON = shite

I just found this board upon searching for where to find replacement caps and the best ways for replacement. I have a ecs k7s5a with the six caps next to the socket dead.
Before I pull the old ones off and replace them with new ones. I was wondering if Nichicon is any good? If it is not, then I'll just go with panasonic. Any suggestions?

[willawake]

Re: ECS-K7S5A/ PCCHIPS-M830LR with GLUXON = shite

nichicon only had problems with a batch of HN and HM series. many people here still trust in nichicon. if you are worried then get panasonic FM.

[MD Willington]

Re: ECS-K7S5A/ PCCHIPS-M830LR with GLUXON = shite

I recapped one recently with some Nichicon PW, running fine as a test terminal.

I also recapped another with some Panasonic FJ's I received from our friends at Soltek, that one is running fine too...

Just don't leave the caps for too long like I did... I miss my K7S5A... lol

MD