Bad Caps Or Stability Problem

[krazykev64]

does anyone know if the board model has suffered from bad caps. the board is an AOPEN MX46 533GN (skt 478). my problem is that the system is very unstable. i have tried windows 2000 pro and server, xp pro and home and also 2003 server std and enterprise. no matter what operating system i try the system is alway unstable. i have run memtest and pc check on the system and it always passes. there is no signs of any bad caps or damage on the board and the PSU is ok. could it be heat related or another problem. maybe i should consign the board to where it came from (the local tip) incase you are wondering i have a brother who works in a recycling centre and he collects computer parts for me. i have had some fantastic parts and built some very good systems from the parts which has made me a lot of money. this board was very good when i first had it (2 years ago) but it has been a pig for the last 6 months

[PCBONEZ]

Re: Bad Caps Or Stability Problem

It would help if you tell us what the caps on it are.

I haven't seen a lot of Aopen boards.
The ones I have seen had a mix of good and bad brands.
They tend to use a lot of G-Luxon outside of the VRM which isn't the greatest idea they even had.

I've forgotten who, but one of the members here is into Aopen boards so maybe he'll trip in eventually.

.

[Harvey]

Re: Bad Caps Or Stability Problem

I've had a MX46 in before now that needed a recap. I can't remember what caps it had fitted as standard, but they where failing and causing instability.

A quick recap sorted it out.

[krazykev64]

Re: Bad Caps Or Stability Problem

I've had a MX46 in before now that needed a recap. I can't remember what caps it had fitted as standard, but they where failing and causing instability.

A quick recap sorted it out.

was there any visible signs of failing caps as my board looks perfect. not sure on what the caps are as its still in the case

[PCBONEZ]

Re: Bad Caps Or Stability Problem

They usually aren't good one day and bloated the next.
There's a time in between where they are marginal and that might be a day or it might be 2 years.
When they are marginal the system will be unstable.

You have a board form a brand with a history of using cheap caps, a board with an apparent history of bad caps, and it's unstable.

I'd say it's time to belly up to the soldering table.
.

[Phenos]

Re: Bad Caps Or Stability Problem

I have recapped lots of Aopen boards. (AK73 and AK77 boards)
The crappy Lelon caps sometimes go bad and blow up from the underside with their vents still flat or bulged a little.

[krazykev64]

Re: Bad Caps Or Stability Problem

i have now removed the board for a closer look and i still cannot see any damage of any kind. there are a few rubycon caps on the board but not in the area of the CPU. i have taken a photo of the caps around the CPU to see if you can ID them. dont worry about the white mark on the lowest cap as its only a bit of heatsink compound off the CPU

[gdement]

Re: Bad Caps Or Stability Problem

Those look like good caps actually.
You have Panasonics at Vcore and Nippon KZE's for the VRM input.
Neither of those fail very often.
There's a G-Luxon over by the USB port but I don't think that's a stressed cap.
The problem probably isn't the caps, at least not those.
What do you have over by the RAM?

[370forlife]

Re: Bad Caps Or Stability Problem

Didn't KZE's from this era have a problem with heat, and go bad under very little heat?

[PCBONEZ]

Re: Bad Caps Or Stability Problem

Nope. - That was KZG and presumably KZJ. - And they are still a problem.
KZE are a much older series. I'm pretty sure they are different electrolytes.
Saw an ad (new product announcement deal) for KZG and KZJ that was hootin' and holarin' about their 'new' electrolyte.
KZE was already an old series by then.

[PCBONEZ]

Re: Bad Caps Or Stability Problem

With reservation I agree with gdement.
With reservation because only 3 KZE is a slight bit light duty for a P4 VRM 'in'. (If there were 4 or 5 that would give me a warmer fuzzy.)
That and I can't see what series the Panasonics are. With only 6 and with KZE on the other side I hope they are FJ series.

Are you sure this wasn't previously recapped?
.

[krazykev64]

Re: Bad Caps Or Stability Problem

there are some black rubycons by the ram slots and a few smaller black caps that i cannot see any marking on. if it not the caps causing the problem them what is? i have enclosed 2 pics of the caps by the ram slots. maybe someone knows what the smaller caps are. to my knowledge this board has not been recapped. my brother gave it to me. he picked it up from the local refuse tip a couple of years back but has been ok up until recently.

[Phenos]

Re: Bad Caps Or Stability Problem

In what way is the system unstable?
I remember i had one Aopen board with freezing keyboard / mouse PS2 and USB ports esp when plugging in. Sounds and content on websites like gif images where still active, replaced the small caps for the ports and the system was back to normal operation.

Aopen used multiple brands of caps, The boards with KZE's and Panny's rarely have problems with the caps because those are good brands.
Other boards were populated with good Rubycon YXG caps and 3 crappy Lelon input caps ruined the stability.

(English is not my native language)

[PCBONEZ]

Re: Bad Caps Or Stability Problem

Those little black ones with the GL are G-Luxon.
- At least that's what I've concluded by seeing them use interchangeably with caps actually marked G-Luxon on different [but same model] boards.
I think they sometimes resort to "GL" instead of writing out their whole name.

Not good to see G-Luxon.
They are junk like the Lelon.

I have some brand new boards with some of those GL on them.
I've been meaning to pull some and check the ESR for cross-reference purposes when I have time.
.

[bgavin]

Re: Bad Caps Or Stability Problem

A tired out Windows installation can certainly be unstable.

Most in my experience are simply slow... I often thought Microsoft embedded a NOP counter loop in the kernel. Every day after installation, the OS adds +1 to the counter loop which inserts a delay after every instruction. This would account for Windows getting slower, the longer it is installed.



In my commercial experience, a fresh XP/SP2 or SP3 installation is never unstable. The introduction of 3rd party software into the kernel ("do you want to reboot now?") can be the introduction of instability.

[krazykev64]

Re: Bad Caps Or Stability Problem

a fresh install makes little difference. the pc is unstable from the start simple as that. it is a pain in the neck. now where did i put my bloody big hammer LOL

[bgavin]

Re: Bad Caps Or Stability Problem

I see no mention of using a different power supply..

[krazykev64]

Re: Bad Caps Or Stability Problem

i have tested it and it passed. it was tested using a proper psu tester. i could try another psu to be on the safe side but i dont think it will be any different

[bgavin]

Re: Bad Caps Or Stability Problem

I'm not aware of a proper PSU tester other than a scope and DVM.

The board is unstable with a variety of fresh operating systems, so it ain't software. A power supply swap will determine Yes or No, then the scope will show Why.

[PCBONEZ]

Re: Bad Caps Or Stability Problem

I'm not aware of a proper PSU tester other than a scope and DVM.

Oh they have one.
But I think it costs like $30,000.