Skyscraper wrote:

F2bnp wrote:

This is an amazing motherboard. I have a P4P800 SE that is apparently dying, it powers up only when it feels like it and I don't see any cap damage. Tried different RAM/CPU/GPU and PSU, but it is merely random when it powers up.

Any suggestions?

If when it manages to power up it runs more or less OK the problem could be defective caps. Some diying caps don't work when cold, but they do once warmed up after several boot attempts.

A cap can be belly up even when it looks OK. All bloated caps are defective, but not all defective caps are bloated.

You can check for abnormal heated up caps, or remove them and test with an ESR meter to check health.
The bad caps would have a high internal resistance and heat up due to unable to filter any ripple's this causes a heatup.
You can build an own ESR meter if youre skilled enough.

Panasonic FM and FR are also good caps.

vetz wrote:

May I ask what is the big deal with this motherboard?

At my work I'm throwing away loads of Socket 478 systems/boards. Don't see the purpose of keeping more than one or two. Thought they had no sale value.

I think easy dual booting win98/winXP could also be an argument for these (AGP for win98).
Some particular i865 Asus models even allow for a s479 adapter, which you can put a very speedy Pentium M(Dothan) into. Which then also allows for(being a mobile cpu) downclocking(bios) all the way to 100mhz(bus) x6 = 600mhz (for any win98/Dos7 programs that works/better at slower speeds).

F2bnp wrote:

This is an amazing motherboard. I have a P4P800 SE that is apparently dying, it powers up only when it feels like it and I don't see any cap damage. Tried different RAM/CPU/GPU and PSU, but it is merely random when it powers up.

Any suggestions?

I have a similar problem on my P5AD2-E Premium, I'll power it up, but it won't post, but holding the power button till it shuts off, and then powering it back on will work, but it degrades, slowly till it takes several more tries. Finally, it wont come on at all. For some reason, regardless of whether its at the point of taking only one additional power-up or it to work or not coming up, reseating the CPU makes it come back.

I noticed a couple oxidized looking contacts on the CPU, the first couple times this happened. Using DE-OXIT on the CPU contacts causes normal power-on behavior for a much longer period of time then without.

Heh, I was practising web archaeology when I found this interesting article at Xbit-Labs.

They were tinkering with an ASUS P4P800 mobo like the one in this thread and laid a temp sensor on one of the unsunk VRM mosfets:

Then run a Preshott 3200 MHz at full steam, and recorded these interesting mosfet temperatures:

132.8 degrees C

I'd dare to say that ghetto-modding heatsinks for them was most definitely a cool (pun intended) idea 😀 .

excellent job on the recap!
I envy that you can order easily quality caps.... 🤣

I may well be linking you to the orthodox church patriarch or something because I can't understand a word 🤣 , but I'm told this is a caps source in Greece:

http://gr.rsdelivers.com/

TELVM wrote:

I may well be linking you to the orthodox church patriarch or something because I can't understand a word 🤣 , but I'm told this is a caps source in Greece:

http://gr.rsdelivers.com/

wow, apparently it works...? there are rates for the Greek Postal Service
shame that they force you to get 5 caps minimum and in most cases it's 10 or 25... and apparently stock is in the UK... don't know what this is all about... meh
but thanks, it seems that with little searching this can work!

keropi wrote:

... shame that they force you to get 5 caps minimum and in most cases it's 10 or 25...

If you search carefully you can almost always find a cap from one of the four magnificents with the specs you need sold individually.

... and apparently stock is in the UK ...

Same here with Farnell, nevertheless the caps arrive in just a couple days.

... it seems that with little searching this can work!

Be advised not every cap series works for every application. For mobo VRMout we want extremely low ESR caps. For PSU output filtering we want relatively low ESR, but not as low as for mobo VRMout. For big PSU input caps ESR ain't critical.