Need to unplug power, wait, then plug the power cord back in to start the system

[c627627]

Old system with a 380W power supply Antec TruePower TP380 powering an Athlon XP nForce2 Shuttle motherboard AN35N Ultra V1.1.

When I power down the system and if soon thereafter I press the power button, everything is fine and the system powers up again. However, if I don't do anything, the system cannot power ON until I unplug the power cord, wait a few seconds, plug the power cord back in and then it will turn on again. Possible causes? (I already reset motherboard CMOS.)

 

[Bobnova]

It's dead, jim.
Odds are it's fallen prey to Fuhjyyu Death Syndrome, aka Antec Used Junk Capacitors Syndrome.

I'm surprised the PSU (and, really, the stuff plugged into it) has lasted this long.
Look in the fan grill/exhaust grill and see if you can see the output filter caps. I'd put decent money on them being bulged/leaking/dead.

 

[c627627]

Will put in a new PSU, thanks Bones!

 

[Bobnova]

Hopefully it's just the PSU, it's possible that the bad caps have caused motherboard damage.
The fact that it will boot makes me hopeful though.

 

[c627627]

100% fixed with the new PSU, doctor.

Resolved.

 

[Bobnova]

Awesome. Thanks for checking back in. Glad I could help.

 

[RJARRRPCGP]

My 2003 True 430 will do that too if the power went out for a split second and came back.
If there's a power company glitch, that's what occurs.

 

[Bobnova]

My 2003 True 430 will do that too if the power went out for a split second and came back.
If there's a power company glitch, that's what occurs.

It's almost certainly dead too. I'd get rid of it before it kills something.

 

[RJARRRPCGP]

It's almost certainly dead too. I'd get rid of it before it kills something.

No visibly bad caps, that's all I can say right now.

And this will only occur if the power was out long enough for it to turn off then the power suddenly goes back to normal, it seems that it may be triggering protection mode.
It's doing better than that 2005 SmartPower 2.0! I wish I can check the caps for signs of drying out.

-> It appears that a sudden mains drop to <100 V immediately followed by >100 V causes this issue. (poco issue)

 

[Bobnova]

Just look to see if they're Fuhjyyu /JunFu caps. If they are, they're dead

 

[dostov]

I'm quite glad I found this thread. My HTPC has a Fortron built 300w mATX PSU that's exhibiting the same kind of issue. Don't want to turn on when it's been off for a while. Power LED just flashes for a second but the system won't turn on. I have to plug/unplug and try again. Usually turns on after a few attempts and when it does it runs fine.

The PSU is FSP300-60GLS that came in Lian-Li PC-C35: http://www.overclockersclub.com/reviews/lian_li35/4.htm. I've had it for at least 5 years now.

Could this be the same thing? Blown/dying caps?

 

[c627627]

Yes it could be. Replace PSU and you can confirm immediately.

 

[Bobnova]

At best that has meh grade Teapos, which are pretty meh. Especially that old.
The green Teapos are decent, the black and gold? Less so. Worse those may be something even worse that uses the Teapo black+gold color scheme.
In any event, I give it a 98% that it's dead.

 

[RJARRRPCGP]

Don't want to turn on when it's been off for a while. Power LED just flashes for a second but the system won't turn on. I have to plug/unplug and try again. Usually turns on after a few attempts and when it does it runs fine.

Those symptoms are bad. Definitely sounds like bad caps. A light that just flashes and fades sounds real bad.

The issue with my True 430 never occurs when the power company isn't having issues. This also happened within the first year of owning it, IIRC, so that couldn't have been bad caps. It was when there was a glitch in the power grid.
Mine never gave symptoms like yours.

 

[dostov]

I'm gonna try another PSU tomorrow and we'll see. I hope it's not it. I'd rather change the mobo than having to find a decent mATX PSU around here...

 

[Bobnova]

The entire Truepower series used Fuhjyyu caps, the 3 year failure rate was well into the 90% range if I recall correctly.

 

[RJARRRPCGP]

The entire Truepower series used Fuhjyyu caps, the 3 year failure rate was well into the 90% range if I recall correctly.

You're correct about the caps going bad on them guys!

Back in March, 2013, all of the Antec PSUs at WinCycle had bad caps!

My 2003 Antec True 430 seems to be one of the longest lasting ones! (The Asus A7N8X-X still boots fine with that guy!) (Still appears to act the same as it did almost 10 years ago!)
(My Asus A7N8X-X always reports low 3.3 V readings and low 5 V readings.)

My 2005 Smart Power 2.0 500W unfortunately had a bulger.
(And my MSI 845 E Max seemed to act strange sometimes, sometimes, it fails to cold boot and it froze on me at least once when I touched the case, likely a loose connector.)