[RetroGuy]

My problem is actually similar to the following:
http://forums.techguy.org/hardware/7...lickering.html
This thread however had no responses.

I know a little more about my problem and hope it can be solved here.. Sorry for making this post so long, but this problem is a real bugger and I'm giving all the info I can.

The problem: When the computer doesn't start
When I plug in the computer, pressing the power button does nothing. This problem is aggravated in winters (weird but true) and when the D-Link ethernet card is plugged in (whichever slot).

When it does start:
In summers, I leave it powered for sometimes, say 20 min.
Gradually the power light on cabinet starts blinking rapidly (on pressing the power button).. a little later the HDD lights also start blinking. The CPU fan turns in jerks and in sync with these lights. A little later, the computer boots normally and works fine after that.
Also, operating it increases the temperature, and subsequently the computer can be made to start without problems.. till it cools down or I disconnect mains.

How I have to start it when it doesn't:
In winters, the above procedure doesn't work. Then I can try one of two things (I usually avoid turning the comp at all, use my laptop instead, since I don't like either method)
I can point a hairdryer from a safe distance at the motherboard, and keep the power button pressed. It starts in a little while.
OR, this is possibly a worse method.. I keep the power button pressed and disconnect mains. After a few seconds the computer powers on momentarily (as if some capacitor is discharging). If I reconnect mains at exactly this time, computer powers on.
Of course I only tried these a few times.. Don't want to short anything with the surges, or toast anything with the hairdryer :-)

What I've found out so far:
I have tried searching the web multiple times for a fix. Others who have had this problem have been told to change their SMPS / PSU - which has worked for some. I haven't tried this yet. Others have been told that their motherboard's VRM (Voltage Regulator Module) is blown and they should change the motherboard.

If anyone knows where the problem really is, please let me know if it can be fixed and how (without changing the motherboard that is!)

Since the computer works perfectly other than this problem, I don't want to change it. If things can be made to work by changing some capacitor (I am guessing one of those is causing the problem) or by changing the PSU, it would be great.

My computer is over 5 years old, a P-4 2.4 GHz that was assembled with an Intel motherboard (D845GEBV2). Everything else on the motherboard works fine, the buses, ports etc..

I have a little soldering experience, a soldering iron, and a multimeter. I'm going to open the cabinet and take voltage readings from the PSU if no suggestions come on this thread..

[Jack Hackett]

Have you replaced the BIOS battery? after 5 years its is most likely dead or nearly dead by now. Get your multimeter on it and check it's voltage (my money is on this)
Have you tested the CPU fan to see if it spins up OK, test on another PC if you have one?
Have you tried booting up to just the POST with NO drives connected with power?
Tried another PSU? Does this PSU work OK in another PC?

[RetroGuy]

I tested the BIOS battery; it gives 3.05 V and so is fine. Anyway the battery is only 1-2 years old, I had replaced the original then.

The CPU fan works just fine once the computer does start up. Anyway I can't test it as I don't have another desktop.

As for testing the computer without load, I had tried that initially when I discovered that the computer boots up when the Ethernet card is not inserted in (any) PCI slot. I tried what you suggested again today; no HDDs, no drives, just the mainboard and CPU 3.3V connections in. No luck.

I think your lead on PSU is good- I opened it up and one of the capacitors has a convex surface, and so is probably blown. I'll try and find pinouts and see if the voltages are right when loaded. Will be right back with reports I wonder though why the Ethernet card is aggravating the problem if the PSU is the culprit here..

I read on some other forum another guy's post in which he had the same problem, changed the PSU only to have the computer work just once and never again. He changed the motherboard assuming that the VRM was blown. Is that possible in my case? Why does the computer operate perfectly fine once it starts if the VRM is gone?

Anyway thanks for the response. I'm working on the PSU thing and will let you know what turns out.

Update: I've tested it with a different PSU. Same problem still there. It seems the motherboard is the culprit. Is anyone familiar with this problem?