Asus P4P800 SE dead

[goodpsusearch]

I found this board without backplate, cmos battery and jumpers and I am starting to believe there was a good reason for that.

I replaced the jumpers, cleaned out the dust and tried to see if it boots.

When I start it without a cpu there is a sound coming from inside of the psu and the 3.3V drops to 3.24V.

If I place a CPU the voltages are ok but there is no beep/post/voice message from line out.

I noticed that the south-bridge gets very hot after some time...

Do you think the mobo is gone?

edit: The Power Supply is 100% ok.

[retiredcaps]

Re: Asus P4P800 SE dead

If I place a CPU the voltages are ok but there is no beep/post/voice message from line out.

I noticed that the south-bridge gets very hot after some time...

Welcome to the club.

https://www.badcaps.net/forum/showthread.php?t=16928

Do you have 3.3V DC on the PS_ON and reset pins?

If your board is like mine, it has OST caps. Members here with more experience than I say OST can fail without bloating.

[Toasty]

Re: Asus P4P800 SE dead

>>I noticed that the south-bridge gets very hot after some time...<<

What is "some time" ??

>>Do you think the mobo is gone?<<

If "very hot" means "you can fry an egg on it" then yes.

Any board discoloration around the VRM regulator FETs?

Toast

[PCBONEZ]

Re: Asus P4P800 SE dead

Do you think the mobo is gone?

No telling.
There are OST all over it.
.

[brethin]

Re: Asus P4P800 SE dead

Make sure you have a good CMOS battery installed.

[goodpsusearch]

Re: Asus P4P800 SE dead

>>I noticed that the south-bridge gets very hot after some time...<<

What is "some time" ??

>>Do you think the mobo is gone?<<

If "very hot" means "you can fry an egg on it" then yes.

Toast

I have 2 boards with the same south-bridge, Asus P4P800 and a Gigabyte GA-8IPE1000 Pro2. After ~20 seconds the Asus south-bridge is starting to get so hot you can't keep your finger on for more than 3 seconds, while Gigabyte's is hardly warm.

Any board discoloration around the VRM regulator FETs?

No.

Make sure you have a good CMOS battery installed.

The battery is ok.

No telling.
There are OST all over it.
.

Welcome to the club.

https://www.badcaps.net/forum/showthread.php?t=16928

Do you have 3.3V DC on the PS_ON and reset pins?

If your board is like mine, it has OST caps. Members here with more experience than I say OST can fail without bloating.

3.34V --> reset pin

3.47V --> PS_ON

I tested every cap on that mobo in circuit with the esr micro and I got reasonable values. Of course I am aware that this is not a safe way to test caps, but I would expect of it at least to boot (and not try to turn the south-bridge into a barbecue :P)

[Toasty]

Re: Asus P4P800 SE dead

You cant test VRM high/low caps in circuit. They're all in parallel so 10 bad caps together will look good.

IIRC a SB that hot, that fast, means it's toast. No pun intended.

[brethin]

Re: Asus P4P800 SE dead

Make sure you have a good CMOS battery installed.

The reason I said this is because the picture shows the board without one yet has jumpers. You said when you got it it had no battery or jumpers so I was just double checking you put a good battery in.

Also make sure you have a fan attached to the cpu fan header. Does it spin up?

Does the green led on the motherboard light up when powerded on?

Dont forget to connect 4 pin power connector as well as the 20 pin.

Try both a agp and pci video card.

My next suggestion is to replace the cmos since it is socketed. You could try reflashing the same one if you have the means. Make sure you flash it with the latest update.

If you have a post card use it, if not get one they are like $5 and are very handy.

The southbridge looks a bit discolored around the edges but that could just be my eyes or the picture.

[goodpsusearch]

Re: Asus P4P800 SE dead

Also make sure you have a fan attached to the cpu fan header. Does it spin up?

Yes, the fan moves normally.

Does the green led on the motherboard light up when powerded on?

The green led lights up when 5vsb is on.

Dont forget to connect 4 pin power connector as well as the 20 pin.

Try both a agp and pci video card.

I don't have a pci video card.

My next suggestion is to replace the cmos since it is socketed. You could try reflashing the same one if you have the means. Make sure you flash it with the latest update.

If you have a post card use it, if not get one they are like $5 and are very handy.

The southbridge looks a bit discolored around the edges but that could just be my eyes or the picture.

I have neither the equipment to flash the bios chip nor any post card...

[brethin]

Re: Asus P4P800 SE dead

For sure get a post card, they cost less than $5 on Ebay. Find a pci video card to test with it doesn't have to be a uber card again about $5 to $10 on Ebay. You can force flash the bios chip on another board if you dont have a programmer as long as it uses the same socket for its cmos using the hotswap method. If your not interested in spending any real time on the board tell me now because I have alot more things you can do if you want to find the problem but cant tell you exactly what it is yet and dont want to waste your time.

If you deside to toss it or sell it I would be interested in it let me know what you want for it.

[goodpsusearch]

Re: Asus P4P800 SE dead

For sure get a post card, they cost less than $5 on Ebay. Find a pci video card to test with it doesn't have to be a uber card again about $5 to $10 on Ebay. You can force flash the bios chip on another board if you dont have a programmer as long as it uses the same socket for its cmos using the hotswap method. If your not interested in spending any real time on the board tell me now because I have alot more things you can do if you want to find the problem but cant tell you exactly what it is yet and dont want to waste your time.

Thank you for the help.

I am wondering if I could find such a card here. From what I have read it is useful for troubleshooting.

The fact that the south-bridge gets warmer than normal, makes me not very willing to spend much time on it.

You cant test VRM high/low caps in circuit. They're all in parallel so 10 bad caps together will look good.

I know that there could be some bad caps in parallel with good ones giving an acceptable total reading, but I doupt this could make the mobo not beep/post at all.

If you deside to toss it or sell it I would be interested in it let me know what you want for it.

I live in Greece, so I don't know if it is worth the effort (packaging, shipping, shipping costs and maybe customs) to get a (possibly) dead mobo.

I never toss bad mbs anyway. I keep them for parts. Sometimes I try again when I get new equipment / ideas / free time



Btw the tiny caps are Ltec, everything else is OST including the VRM caps and hopefully there are 4 x 1200uF 16V Chemicon KZE. Those are the only ones that can be used for recapping.

[PCBONEZ]

Re: Asus P4P800 SE dead

Swap out the OST and see what happens.
ESPECIALLY the ones in Vcore.
You can't measure those in circuit and one bad one there can kill the whole board by not letting the CPU start.
.

[brethin]

Re: Asus P4P800 SE dead

I know these ASUS P4 series boards well and have revived many from the dead that others have given up on. They are not troubleshooter friendly but cant be fixed most of the time.

Your board should have 4 16v 1200uf and 6 6.3v 1500uf caps in the VRM they used several different ones when they produced these boards, OST Chemicon KZE Chemicon KZG etc. Just replace all 10 if your going to do any cap replacements before you replace anything else on the board.

I normaly dont do this just yet (I check a few more things first) but do end up doing it after all is said and done so if you want to spend the time and cost for those 10 caps now go right ahead but I cant promise it will fix it.

[PCBONEZ]

Re: Asus P4P800 SE dead

The 1200uF 16v in the photo are KZE. - Those should be fine.
The rest of the board including the Vcore caps looks like mostly OST.
His in-circuit check says they are okay but you can't check Vcore in-circuit.
.

[brethin]

Re: Asus P4P800 SE dead

From my experience with these ASUS P4 series its best to replace all 10 in the VRM. The 4 16v 1200uf often fail or fall short on these boards and show no signs no matter what brand they are. Most of the time they are KZE but I have seen others including Rubycon go bad here and show no physical signs of failure. Heat is bad in this section of the board unless you use extra cooling over the VRM. Thats why ASUS started using heatsinks in the VRM on the P5 series. The exception to this rule in the P4 series is the P4C800 boards as they moved them all to the side to keep them cooler but it places them all under the PSU and if the PSU has no intake fan then it results in the same problem.

[goodpsusearch]

Re: Asus P4P800 SE dead

I am going to order caps...

[goodpsusearch]

Re: Asus P4P800 SE dead

Your board should have 4 16v 1200uf and 6 6.3v 1500uf caps in the VRM they used several different ones when they produced these boards, OST Chemicon KZE Chemicon KZG etc. Just replace all 10 if your going to do any cap replacements before you replace anything else on the board.

My board has 4x16V 1200uF KZE and 7x1500uF 6.3V OST RLZ 8mm caps.

What caps would be suitable to replace the RLZ?

[kc8adu]

Re: Asus P4P800 SE dead

really hot sb=dead board.warm ok.too hot to keep your finger on bad.

[Toasty]

Re: Asus P4P800 SE dead

Thanks for the confirmation kc!

@goodpsusearch - Since you insist on this foolishness....

>>What caps would be suitable to replace the RLZ?<<

Poly's or Nichicon HZ or Ruby MCZ. That's vCore.

Toast


Oh, and FYI regarding -
>>I know that there could be some bad caps in parallel with good ones giving an acceptable total reading, but I doupt this could make the mobo not beep/post at all.<<

If they are shorted, it won't.

.

[PCBONEZ]

Re: Asus P4P800 SE dead

.

.
115C = 239F and it's in spec.
If you can hold your finger on that then more power to ya.
.