asus p4c800 filter cap recapping question

[ChaosLegionnaire]

just bought a replacement mobo for my msi 875p neo2-p that died and refused to return to life even after recapping the ost rlx crapacitors in the vrm.

unfortunately, this asus p4c800 i bought is also affected by the capacitor plague... it has the following caps on board:-

4 x 1200uF 16V 0.022 Ohms 2150mA Nippon Chemicon KZE 10mm(Ø) x 25mm(H) @ CPU VRM In Area
8 x 1500uF 6.3V 0.021 Ohms 1650mA OST RLX 8mm(Ø) x 20mm(H) @ CPU VRM Out Area
17 x 1000uF 6.3V 0.072 Ohms 760mA OST RLS 8mm(Ø) x 12mm(H) @ NB Area and AGP/PCI Slot Areas
6 x 100uF 16V 115mA OST RLG 5mm(Ø) x 11mm(H) @ Onboard Sound Chip Area and Fan Headers

thus, to prevent history from repeating itself, i shall be rid of all the ost crap that caused me to lose one of my fav boards.

interestingly, the p4c800 is exhibiting the same symptoms as my msi 875p neo2-p before it (im referring to the msi) died...

1. wont power on sometimes. as if no power connected. psu is a branded known good working enermax liberty 500w. therefore, its not the psu. so my guess its the ost crap breaking the power on trigger with too much ripple below the required voltage to signal #pwron or #pwrgood

2. when system boots, it keeps saying either "cmos error defaults loaded" as if i cleared the cmos which i did not do or "new cpu installed" when i did not change the cpu while the system is off. it also powers up with an anomalous vcore reading that is too low or high though fortunately not high enuff to kill the cpu. im guessing the ost crap is producing too much ripple again causing glitches in the logic id circuit of the cpuid & vid and also possibly corrupting the bios image as its being copied into ram for fast booting.

3. the system clock is frozen in time at the time the mains power is shut off. cmos battery voltage has been checked out and is fine. battery terminal contacts underneath the board have been probed with a multimeter and the contact is good. so once again its most likely the ost crap not being able to buffer anything from the cmos battery or producing too much ripple or inadequate power causing the system clock timer to become bugged and not ticking properly.

so my whining aside, i've found the following jap caps (no racism or pun intended) to replace the ost crapacitors:-

1500uF 16V 0.013 Ohms 2550mA Panasonic FJ 10mm(Ø) x 20mm(H) @ CPU VRM In Area (i know kze is a good cap that doesnt fail but its esr is a little too high for my taste. i think fj is a good upgrade.)

1500uF 6.3V 0.016-0.019 Ohms 1870-1950mA Sanyo WG 8mm(Ø) x 20mm(H) @ CPU VRM Out Area

1000uF 6.3V 0.030 Ohms 1140mA Suncon WG 8mm(Ø) x 11.5mm(H) @ NB Area and AGP/PCI Slot Areas

1000uF 6.3V 0.030 Ohms 1140mA Nichicon HM 8mm(Ø) x 11.5mm(H) @ NB Area and AGP/PCI Slot Areas

however, im not able to find a cap to replace the 100uF 16V 115mA OST RLG @ the fan headers and sound chip area. hopefully, its not really necessary to recap those i think?

so my question is this: is it okay to replace the 72 milliohm ost rls filter cap with a very much lower 30 milliohm low esr cap simply for filtering purposes? will it be too low an esr and affect the circuit and/or how it filters ripple?

btw i intend to use a radeon 9800 pro with this board and its known to be a heavy guzzler of 3.3v power. so i was thinking i need good caps to support the 3.3v guzzling 9800 pro thus the decision to go with low esr, high ripple caps. keke~

thanks~

[delaware74b]

Re: asus p4c800 filter cap recapping question

The KZE's are fine, I have not seen a failure with those from UCC.

The OST's need to be replaced, with the exception of the 5x11mm ones. I haven't seen a problem with leaving the smaller ones. I don't replace these unless I continue to have problems after a re-cap. I suspect the OST's in the CPU vrm section to be the culprit.


Does this Asus board have a jumper to clear the RTC and CMOS? (it resets the clock and the CMOS back to factory defaults

I would highly recommend you fully check the power supply, especially the +5VSB. These power supplies have a history on this site for failing to start. See this link:

https://www.badcaps.net/forum/showth...x+liberty+500w

I think you should try a known working, good quality power supply before tearing into a recap of the motherboard. You stated you are haveing a similar problem after changing mobo's. IMO, that leaves the power supply as an issue.

[ChaosLegionnaire]

Re: asus p4c800 filter cap recapping question

yes the board has a clear rtc jumper.

however, now the board simply cannot power on anymore. very rarely, i see it starting and then stopping in a few seconds. changed to an fsp amacrox and still same dice. for some reason, it cannot stay powered on for more than 1-2 seconds... i have tested both enermax and fsp psus on my athlon 64 system which uses a power guzzling 6800 ultra and they both work without problem.

so since im sure its not the psu, can badcaps in the +5VSB line cause a board to not start or intermittently fail to stay powered on?

[ChaosLegionnaire]

Re: asus p4c800 filter cap recapping question

lol just left the bare board aside for a couple of hours and then tried again. this time it managed to boot without problem. so slowly added the cpu, ram and video card back. then the dvd drive.

hmm so it seems on a cold boot, the board cant take so many components together being powered on. have to slowly add them back one at a time to get it to power on.

interestingly, the msi 875p that died would also come back to life intermittently if left aside for a while until it died permanently...

damn really hope all this glitchiness is caused by the ost crapacitors. will have some time over the weekend to recap all 29 capacitors which shud take me several hours.

[delaware74b]

Re: asus p4c800 filter cap recapping question

interestingly, the p4c800 is exhibiting the same symptoms as my msi 875p neo2-p before it (im referring to the msi) died...

Straight out of your first post. I'm not trying to sound like an a**, but I really think you should do the following:

1- check your power supply, or replace it with a known good model. I think this is half your problem. Bad caps in a power supply will cause the esr to be high (out of spec) until they warm up (heat causes the esr to drop). Bad caps will also cause a power supply to not deliver enough stable power to run a system. Your system should not need more than a 430-watt supply unless you're running 2 hdd's, 2 dvd's, etc.

2- Replace the 8mm diameter OST's on your board. The 5mm ones normally don't cause problems with booting.

[Toasty]

Re: asus p4c800 filter cap recapping question

There is also a thread in here somewhere on recapping these. Kc8adu and willawake did these. I have too and they really perform well. There is also a poly mod for these and a hybrid mod too (mix poly and regular caps). Mine was OC'd 25% and stable for many years.

Follow delaware74b's advice and get a good PSU in there or fix the one you have. A flaky PSU will wreak havoc on -any- system.

T

[ChaosLegionnaire]

Re: asus p4c800 filter cap recapping question

just recapped the vrm caps a few days ago. all the problems that were plaguing the system previously are gone. i just need to find a new soldering iron tip to continue recapping all the 3.3v and 5v filter caps as i exhausted my long life tip recapping 3 motherboards.

[Toasty]

Re: asus p4c800 filter cap recapping question

Sweet!

[ChaosLegionnaire]

Re: asus p4c800 filter cap recapping question

recapped the 17 filter caps 2 weeks ago and been running 12 hours a day without any problems. i also ran all sorts of stress tests without any problems. i can now turn on and off the mains power repeatedly without any cmos errors so i think i now have a perfectly functioning asus board which is a surprise haha~ a perfectly functioning asus board... lol~

[puterhater]

Re: asus p4c800 filter cap recapping question

recapped whole board still no boot

[puterhater]

Re: asus p4c800 filter cap recapping question

sorry that was a test I cant seem to make a new post

[Almighty1]

Re: asus p4c800 filter cap recapping question

I have a question, is the P4C800 and the P4C800-E Deluxe which is labeled P4C800-E actually the same board because I noticed from this image: http://www.tamayatech.com/ProductIma...US-P4C800E.jpg

when I counted, there are only 34 capacitors in total but the first post shows 35? Could it just be the revision of the board?

[momaka]

Re: asus p4c800 filter cap recapping question

when I counted, there are only 34 capacitors in total but the first post shows 35? Could it just be the revision of the board?

Possibly.

You already posted in two other P4C800 threads, though. Don't be digging up all of the ASUS P4C800 threads now!

[Almighty1]

Re: asus p4c800 filter cap recapping question

Possibly.

You already posted in two other P4C800 threads, though. Don't be digging up all of the ASUS P4C800 threads now!

I just remembered the difference between the P4C800 and P4C800E, the later which is what I have. One had the 3Com NIC and one had the Intel NIC. So this is one thread I shouldn't have posted in originally.

[ChaosLegionnaire]

Re: asus p4c800 filter cap recapping question

i'm posting this to celebrate the two and a half year anniversary of fully recapping this board. these past two and a half years, the board has been running 12x7x365 in excellent fashion.

the only two gripes i have are the lack of or poor anti-static protection for the southbridge and the buggy sound drivers on rare occasions distorting the sound when a program requiring sound is run. when it occurs, i have to restart the program to get the proper sound back.

due to the lack of or poor anti-static protection for the SB, whenever i need to connect or disconnect anything to the board, be it the onboard headers/connectors or the back panel connectors, i have to shut down the system and unplug the power cord. the board simply cannot tolerate hotplugging anything without the power cord unplugged.

if i dont follow the above, then the board will lockup at the power off state and refuse to power on. (changing psu has no effect so its not the psu) i have to remove the cmos battery and short the power switch headers on the board with a jumper and leave it overnight. then it will turn on again in the morning. i've had to do this three times already so far to get the board back to life. will have to be very careful in NOT messing with/touching this board when it is in operation...

[Wester547]

Re: asus p4c800 filter cap recapping question

due to the lack of or poor anti-static protection for the SB, whenever i need to connect or disconnect anything to the board, be it the onboard headers/connectors or the back panel connectors, i have to shut down the system and unplug the power cord. the board simply cannot tolerate hotplugging anything without the power cord unplugged.

Intel, in their infinite wisdom and in order to preserve the then high-speed signal integrity of USB 2.0, made certain that the ICH5 southbridge lacked the proper ESD protection. This meant, especially if the front USB ports were used (those that usually aren't "grounded" to anything except "plastic"), that the southbridge would die very often by way of the ESD incurred by hot plugging. ICH4 was affected by this to some extent as well. That's what you're experiencing.

if i dont follow the above, then the board will lockup at the power off state and refuse to power on. (changing psu has no effect so its not the psu)

Good thing it's latching - if it didn't do that, the southbridge would be shorted and fried by now. On the other hand, it must be a pain in the behind to have to turn the system off in order to disconnect or reconnect anything...

[TELVM]

Re: asus p4c800 filter cap recapping question

... specially if the front USB ports were used (those that usually aren't "grounded" to anything except "plastic") ...

-modding to the rescue:

[ChaosLegionnaire]

Re: asus p4c800 filter cap recapping question

lol nice~ i tried that on my board but with mixed/partial results. i also tried attaching the grounding wire to one of the screws on the psu housing. both times i get "cmos settings wrong. defaults loaded" when trying to power on my system after tinkering with it without unplugging the power cord. its as if i tried to clear the cmos which i did not do.

i also get that cmos error albeit sometimes or only rarely on some of my other boards with proper esd protection for the SB when i did not observe proper esd precautions and did not unplug the power cord.

oh well, i suppose that is fair enuff for a ghetto esd protection mod for this ich5 SB board. at least the PW latch did not break when i tried to tinker with the board!

the docs for some esd sensitive devices also state that "even though the esd sensitive device has on-chip protection against accidental esd discharge, proper esd precautions should still be observed when handling the device." so i suppose on-chip esd protection isnt actually 100% foolproof or 100% perfect and u'll still screw up your esd sensitive chips if u act like a bull in a china shop as far as esd precautions are concerned...

[TELVM]

Re: asus p4c800 filter cap recapping question

... tinkering with it without unplugging the power cord ...

^ Not a good idea. Always unplug PSU, then keep the comp start button pressed for at least ten seconds to discharge everything before tinkering.


To properly ground to chassis some frontal USB ports that are "floating" on plastic you need a wire as thick or thicker, and with as shorter a path to chassis as possible, than the USB GND wire that goes to the mobo USB connector. This way we ensure that the little "lightning bolt" of static electricity from your fingers, in its quest to follow the shortest and thickest (= easier) path to ground, will find the extra grounding wire irresistible.

Not 100% foolproof beause a powerful enough ESD discharge might still zap the mobo regardless, but miles better than "floating" ports (where mobo will eat the full ESD discharge).


Of course a properly grounded home electrical installation will help.


I keep running a P4P800 system on a cheap case with plastic bezel and "floating" front USB ports, that froze from time to time when inserting flash drives in the front USB ports. After ghetto-modding this:



There has been no more freezes to date.

[momaka]

Re: asus p4c800 filter cap recapping question

Intel, in their infinite wisdom and in order to preserve the then high-speed signal integrity of USB 2.0, made certain that the ICH5 southbridge lacked the proper ESD protection. This meant, especially if the front USB ports were used (those that usually aren't "grounded" to anything except "plastic"), that the southbridge would die very often by way of the ESD incurred by hot plugging. ICH4 was affected by this to some extent as well. That's what you're experiencing.

^ Good info.

My Dell Optiplex 170L has ICH5, but I've never had those issues. I guess Dell grounded the front USB ports properly. That said, I do also have a GX270 motherboard and front header connector, but no case for it. So I will keep this in mind and make sure to ground everything.

This way we ensure that the little "lightning bolt" of static electricity from your fingers, in its quest to follow the shortest and thickest (= easier) path to ground, will find the extra grounding wire irresistible.

Hehe, that's funny way to say it.
Lightning bolt says: Mmmmmmmmmmmmm that thick wire! -So irresistable!