Computer will POST only after a dozen boot attemps

[Hugo]

Hi! My computer has been acting strange for a few weeks now. My caps look OK but here are the symptoms.

When I push the ON button, it powers up properly: the PSU fan starts, keyboard lights flash, the hard disk makes a sound and the internal speaker makes its normal short beep.

Then........ nothing. The screen stays dark and absolutely nothing happens. The keyboard and the mouse aren't powered (no reaction when I press the caps lock key). No POST, no more hard drive noises. The PSU fan is still running and a few diods are on, but that's all.

I then press the ON button for 5 seconds to turn off the computer, I try again... same thing... again... again... then, after 4 to 12 successive attempts, the computer FINALLY starts booting. Once it's booted, it's absolutely stable. It can run for days without crashing or freezing.

I have a few suspects but I need your opinion.
- Could it be a "bad caps" problem?
- Is the PSU dying?
- Is the large amount of dust killing my computer (the house is dusty because we're renovating)?
- Or maybe the BIOS battery is dying?
- Or it's a problem with loose internal wiring or cards?
- Too many peripherals for my PSU? It that even possible?

The computer is a P4 genuine Intel, 2Ghz. 512Mb memory in one bank. Motherboard is Intel too. I also have a few peripherals installed: Radeon 9200 video card, USB 2.0 4-ports extra card (with 3 devices in: scanner, fax/printer, camera), 2 CD/RW-ROM drives, 1 hard disk (80Gb Maxtor), 1 floppy drive, standard mouse, standard keyboard. I use the internal sound card and network adapter. Oh, and I have one extra case fan, pumping the air out.

Motherboard: Intel D845WNL (Pentium 4)

I can't find any info about the PSU, it looks very ordinary and nothing specific is written on it (no brand or model info).

[cods69]

Re: Computer will POST only after a dozen boot attemps

I'd replace the PSU (with a decent one) first, regardless.
At least you know you have good power to the mobo and other devices then.

[tylerlough]

Re: Computer will POST only after a dozen boot attemps

I'd replace the PSU (with a decent one) first, regardless.
At least you know you have good power to the mobo and other devices then.

It's likely the PSU, starting it many times warms it up and PSUs work better when warm. A good psu is important, think what your pc is with out power; it's a big a$$ paper weight.

[Hugo]

Re: Computer will POST only after a dozen boot attemps

Well I'm happy if the problem isn't capacitor related.

What type of PSU is good for a Intel P4? 400 watts?

I'll change the PSU and the BIOS battery, just in case. Just one stupid question: if I remove the BIOS battery, will the BIOS lose any information?

I've assembled or repaired many computers, but I'm really not an expert on components and electricity.

[tylerlough]

Re: Computer will POST only after a dozen boot attemps

400 watts is overkill, your system only draws from 70-100 watts at full load
look at this but you should read the whole thing too.
http://www.silentpcreview.com/article28-page4.html
And yes you will lose the BIOS settings but not the BIOS info; the settings just go back to default and then you change them back
A power supply has capacitors too and they do go bad but most people just get a new one if they go bad.
a good way to pick a psu is by weight, if it ways 10oz and is 400 watt it is not a good power supply
a 250-350watt one would be fine
other people hear know about what brands are good and what are not
check this out too
http://www.tomshardware.com/2005/07/11/stress_test/

[Chris1992]

Re: Computer will POST only after a dozen boot attemps

If the BIOS battery is removed, you will lose BIOS info. I have a P4 running off 250w.

[willawake]

Re: Computer will POST only after a dozen boot attemps

take a look inside the psu. it may have badcaps there. badcaps on the mobo can do exactly that and badcaps in the psu can give same kind of issues. if the system is still stable the good caps on the mobo are probably filtering the bad power from the psu well.

if you find some bulging/leaking take a pic for us.

if it is lightweight and cheap, would be better to replace it. FSP Group (Fortron) seems to be a favourite here. Also Seasonic, PC Power & Cooling, Zippy, High Power/Chieftec.

the spec quoted on some psus are peak and not sustained. ie you get much less actual wattage than what you paid for.

[Newbie2]

Re: Computer will POST only after a dozen boot attemps

I can't find any info about the PSU, it looks very ordinary and nothing specific is written on it (no brand or model info).

No sticker is on the side of that PSU?

Can you take it out and please if you can post pictures of the insides of the PSU.

[tylerlough]

Re: Computer will POST only after a dozen boot attemps

- Too many peripherals for my PSU? It that even possible?

yes it is possible to over load the 12volt rail, this is were over 75% of the power comes from on the modern system. I'm not sure if the 75% thing is true for stuff older than a P4 system. It dosen't really matter about the total watts, just look at the amp rating for the 12volt+ line it should be more than 8amps just to be safe.
peripherals such as fans and pci cards only draw about one or two watts each so thoses aren't big problem.
Likly root of your problem is a POS PSU or faltly mobo.

[linuxguru]

Re: Computer will POST only after a dozen boot attemps

+5Vsb should be rated for 2A or higher for most Intel P4 boards. I've seen power-on problems similar to what you've described due to an overloaded +5Vsb rail, often due to dried-up electrolytics on the auxiliary power supply in the PSU.

[Hugo]

Re: Computer will POST only after a dozen boot attemps

Yayyy! I've installed a new PSU and the system boots normally now! Even better, there used to be a slight case of interference on the monitor, and now it's gone! This system has always acted kinda strange. It's 2 1/2 years old but I suspect some of the components are older. In the past months this system suffered from a dead monitor, a dead keyboard, 2 dead CD-ROM drives. A serial killer feeding on peripherals.

My new PSU is a 350W Enermax with a lot of cool options. It's got a dual fan, is adjustable, not noisy at all, and has a 3 years warranty. At 70$ it's a very good value.

Now, for the old PSU, I have some more news. I've found the sticker on the back of the unit. It's a "L&C Computer Co., Ltd", model is "DR-A300ATX". YOU SHOULD NEVER BUY ANYTHING COMING FROM THIS CRAPPY COMPANY. This PSU is most certainly the cause for all my problems, from fried peripherals to the latest boot problems.

I've opened the PSU and I've found the ugly part. FIVE CAPACITORS ARE DAMAGED. Three medium size caps are swelled, and discharged from the top. Two huge caps seem to have leaked from the bottom.

Unfortunately I don't have my digital camera right now, but I'll keep the old PSU and post a few photos when I have the time.

Here is the dead capacitors info:

Fuhjyyu 1650uF16V; top bulged and leaked

Fuhjyyu 1000uF10V (2x); top bulged and leaked

CapXon 330uF200V (2x); massive leak suspected from the bottom*
(*or it might be a sealant or an isolation foam, I'm not competent enough to tell the difference)


Thanks all, now my system runs smoothly. Replacing the PSU cost only 70$, an hour trip downtown and 15 minutes of easy work. I'm a happy camper.

[Rainbow]

Re: Computer will POST only after a dozen boot attemps

L&C and DEER are known crap PSU manufacturers.
There's a lot of bad Fuhjyyu caps recently.
The substance around the bottom of the big caps is most likely some kind of glue - it's present in most PSUs.

[Newbie2]

Re: Computer will POST only after a dozen boot attemps

Are you going to recap this L&C (Deer) power supply?

It can be a temporary backup, but chances of the Enermax failing are really, really low. But, I keep any PSU that still works, even these crappy L&C power supplies.

[kc8adu]

Re: Computer will POST only after a dozen boot attemps

i doubt i would bother with recapping that one.
i see far too many catastophic failures with deer units.as i say non passive end of life.

[Hugo]

Re: Computer will POST only after a dozen boot attemps

This PSU is probably worth 15$-17$, I wouldn't bother recapping just for the fun of it. At least I know what failed -- the capacitors. But I'd say this PSU was producing low quality voltage from day one; it just doesn't filter right.

I've just realized how computer shops can come up with "fantastic offers" by using some cheap components where the customers won't look (PSU, USB cards, generic components such as CD-RW players). If you choose an excellent motherboard with the best CPU around, it's almost criminal to install it in a cheap case with a disastrous PSU.

[kc8adu]

Re: Computer will POST only after a dozen boot attemps

a store i work with found out the hard way about these crap psu's
echo star,a-power,powmax,mge,deer they had them all.in a good box with extra fans the apower and mge last 2 months before they get dirty enough to cause the system to become unstable.
like i said earlier 500w my ass.
weighs less than a pound.
psu orders go thru me now.everyone got tired of these things coming back like a boomerang.
gotta take a pic of the heap o junk before they get sent back to evertek.there is at least a dozen from the last month.

[Hugo]

Re: Computer will POST only after a dozen boot attemps

Was Enermax a good choice, then?

The only other option in the hardware shop was a 160$ PSU with a front panel display of the temperature and a knob. Nice, but too expensive for me.

I live in a not-so-big town so the choices are sometimes limited.
But I wouldn't trade the landscape for more computer shops!

[Hugo]

Re: Computer will POST only after a dozen boot attemps

There it is:
http://www.enermax.com.tw/english/pr...y1.asp?PrID=29
It's about the least expensive of their products, but it's got the same quality as the more expensive ones.

Nice little thing. Saved my computer's life.
And it was a pleasure to install.

[Hugo]

Re: Computer will POST only after a dozen boot attemps

For the record, here's a tentative picture of the 3 caps. Unfortunately, the goo over the 2 caps on the left had dried, and it partly went away when I cleaned up the board with a vacuum cleaner.

[tylerlough]

Re: Computer will POST only after a dozen boot attemps

i have a soon to be replaced L&C and I replaced thoses same three caps that were bad and now it is doing ok.
Enermax is a good brand but i've seen some reveiws of them going up like the 4th of July or in your case canada day(I think). That was for the 600watt, people said good things about the 350watt.