Desktop PC Startup Issue

[thunderchildobs]

I have a start up problem on my 2010 Dell Inspron Vista Desktop.

If I turn on the mains power, then turn on the PC straight away (holding down the on button) , for a split second there is power, the keyboard lights up, the fan on the video card starts up, but not the fans on the power supply, the power shuts down. Keeping On button press down, the power comes on, then goes off, and the cycle keeps repeating.

Now the interesting part, If I turn on the mains power, but not the PC and wait for 20-30 minutes and then turning the PC on, the PC starts / boots normally.
The PC has power during this 20-30minute period, lights on the motherboard are lit up.

I have done the following,
1) Blown a ton of dust out of PC.
2) Replaced the CMOS battery
3) Remove and reinserted all the memory / video cards.

None of this has helped.

Once the PC does start, it works normally.
All the fans work.
There has been no unexpected shutdowns or window crashes.
The PC is regularly on for 6 hours a day, guessing it is not an overheating problem.


Any suggestions?

Thanks

Brendan

[redbeard]

Hi Brendan,

Perhaps a power supply issue.

Power supplies can do weird things. It could also be that you have added things over time to your PC and the power supply is at its limit with the power.

Perhaps when you first turn power on, some devices power up and reduce the initial load so when you then turn on PC, the rest powers up.

How many watts is your power supply and do you power lots of devices including external USB's.

Not exactly sure what you mean by holding the power button down on as normally it's just a quick press and you let go, you should never actually have to hold the power button down.

On all modern PC power supplies, if you hold the power button in for 6 seconds, the power supply will switch off.

Hope that helps.

Cheers,

Damien.

[ZeroID]

Battery is dying, it's 7 years old. Even on Mains at first power up power goes through the battery to the PC and it is not holding charge. Leave it on for a while and the mains props it up enough to let it kick start.
Simple test, Pull the battery out completely and start just on mains power. Should start straight away, confirms battery problem.
Good luck trying to find one after 7 years though.

[LewisM]

Had same with 2 of the wife's laptops - both dead/dieing batteries. Just replace them. Not cheap, and I strongly advise AGAINST non-OEM batteries (after I had 2 "repro" batteries get exceedingly hot to the point I threw them in a bucket of sand for 3 days before disposing of them properly)

I had a good battery in mine, but a faulty power supply, so simply replaced that. I also suggest buying a reputable brand power supply if not the original (I bought 2 multi-PC types, which were not cheap, but lasted 2 years no issue so far)

It's nearly always the battery...

[Merlin66]

I'd also say the battery....
I've had similar problems with my observatory Compaq laptop.....
Just ordered a new battery.

[astro744]

It's a desktop so no battery other than non-rechargeable CR2032 for the CMOS. Most likely PSU. Try a different power port on the PSU for your peripherals else try new PSU. MSY has some cheap ones, maybe others stores too.

[ZeroID]

Ooops, Yeah, sorry. All our stuff at work is laptops, went into fix stuff mode without thinking.

Done a BIOS diagnostic on it ? Tap F12 @ startup.

Normally PSU's just fail outright, the smoke escapes, never been able to put it back in.

[Shano592]

I'll go with a degraded power supply. Maybe as Brent has suggested, some of the smoke has escaped over time.

If it is really 7 years old, then you may just need to source a new PSU - probably with a higher capacity.

[LewisM]

Yeah, well there ya go :) I just read that Kiwi guy and kept it going :P :lol:

[LewisM]

Actually, power supply IN the PC case - had 2 fail (one spectacularly with a loud BANG). They do weird things.

[ZeroID]

The capacitors are normally the things that go in PSU's. that where the smoke is held and is the generator of loud bangs. They dry out over time. Also the same in older UPS hardware btw. Capacitors are very similarly constructed as batteries, two conductors separated by a dielectric film with a gel electrolyte.
Rectifier diodes are the other culprits, they only have a little bit of smoke.

[ZeroID]

Sorry for misleading ya Lewis :rolleyes: Yeah Right :D :lol:

[sil]

How many other things are plugged into the same mains circuit? I bet over the years you've been accumulating wall warts to power external drives, hubs, charge phones etc. Each circuit is only rated to draw a certain current and you could be straining it. Especially cheap power boards have a tendency to be dodgy with their poor soldered connections.

[acropolite]

If it's a power supply issue (likely) don't waste your money on a new PSU, there are plenty of refurbished Dell desktop boxes on ebay. We bought 5 for work all under $400 for i7 with 8g ram and all with W7 pro licences and W10 upgrade pre-loaded. Also capable of running dual monitors with an additional display port adapter $20 from the same buyer.

http://www.ebay.com.au/itm/Dell-Optiplex-990-i7-2600-3-4Ghz-QC-8Gb-Ram-180Gb-SSD-W10Pro-Desktop-/252775706347?hash=item3ada9b2eeb:g: 12YAAOSwOgdYp3Hd

[BPO]

Sounds like a failing NTC thermistor in the PS.

[thunderchildobs]

Thanks for the suggestions. It was the power supply in the end causing the problems.

[dpastern]

not from my experience - I've seen PSUs decline gradually - still function, but have issues. Some do die straight away though. It's not really that clear cut imho.

OP - my diagnostic guess is the PSU.

What is the current PSU's rating, and how much stuff do you have in the PC? If you've added new graphics cards, more hard drives etc, you may be taxing things from a power perspective.

I'm also pretty damn positive (PDP!) that Dell's PSUs will be crappy cheapo Chinese stuff. Knowing Dell, you probably won't be able to change the PSU lol...

edit: I'll add that I just noticed it was the PSU - glad the issue is fixed. On a side note, a failing PSU may damage the caps on the motherboard - I would recommend a quick visual inspection (with power off and plug disconnected for at least a minute to allow caps to drain) to see if any caps are showing domes. This may help you identify them:

http://apike.ca/content/2012/11/how-find-bad-capacitors-tv.html

once caps start to bulge, the electronics item will eventually fail. You don't wanna be near a cap popping (exploding)!