DId my psu just die?

heton · 15 Feb 2020 at 20:05

Hi, I had my phone connected to my PC to add stuff to some folders on phone,when the PC just went off...no bang or nothing.
I checked plug fuse and also took cover off psu to see if it had a fuse...which it did but was ok also.
I will take psu up to brother in law tomorrow to check it but was just wondering is there anything else other than the psu that caused the PC to die?
The psu was a 550w unbranded,I don't have a graphic card installed so a 550w should be big enough?....any suggestions for new psu,if I need one
CJ

Mcnumpty2323 · 15 Feb 2020 at 20:11

Paperclip test the psu
See if the fan spins
Paperclip, bit of wire etc
From green wire pin to black wire pin
On 20/24 pin plug
With all psu cables disconnected
From pc just to be on
The safe side

heton · 15 Feb 2020 at 20:30

Thanks,any black cable? there's a few on that connector

heton · 15 Feb 2020 at 20:47

Ok ,just connected the green to a black and psu fan works....so not psu?,thanks for that tip....hmmm so what next to test?

EsaT · 15 Feb 2020 at 20:56

heton said:
The psu was a 550w unbranded

Then it was more likely about 300W max PSU...
When new and before no doubt crap quality capacitors started degrading.
Those cheapos can be literal fire hazards at their "best".
https://www.theregister.co.uk/2012/11/26/exploding_computer_vs_reg_reader/

You got any picture of its "spec" sticker?

heton said:
Ok ,just connected the green to a black and psu fan works....so not psu?,thanks for that tip....hmmm so what next to test?

PSU stays on only for as long as motherboard tells it to stay powered. (by pulling that same green wire to ground you did)
And with very questionable quality PSU voltages and ripple might be so out of whack that motherboard couldn't anymore work properly anymore.

Certainly wouldn't feel lucky about trying that PSU in PC without some more thorough testing of it, if you give any value to PC parts.

heton · 15 Feb 2020 at 21:50

.....EsaT
hmmm no pic

heton · 15 Feb 2020 at 22:17

heton · 15 Feb 2020 at 22:32

Here's the details on the PSU ....CP4-550W
Model; XEM-FB550WCE

Quartz · 15 Feb 2020 at 23:22

heton said:
CP4-550W

Best guess from Google on that is Jersey Power. IOW a no-name POS that should be replaced ASAP

In the IMG link you need to includer the .jpg.

.

EsaT · 15 Feb 2020 at 23:27

heton said:

Works better when not "hotlinking":
http://www.imagebam.com/image/74eb4b1334185720
That isn't even 300W by any standards.
And in PC tech timeline that's so ancient it's not even from time of Hadrian's Wall, but from time when trilobites were the highest life forms.
Doing even 200W properly would have been questionable.

So would say you're lucky it didn't try to burn down your house.
Because it's 99+% sure it hasn't passed those safety testings and only safety testing was that it didn't burn factory down when test fired.
Any even 10% respectable maker scrapped those designs over 15 years ago and only dishonest makers would have been selling those then.

Pretty good bet it would be in worser end of these:
http://www.jonnyguru.com/blog/2007/09/14/the-bargain-basement-power-supply-roundup/
https://web.archive.org/web/2014090.../modules.php?name=NDReviews&op=Story&reid=123
https://web.archive.org/web/2014102.../modules.php?name=NDReviews&op=Story&reid=324
https://web.archive.org/web/2018101.../modules.php?name=NDReviews&op=Story&reid=335

Don't try to connect that into any PC parts you want to keep in working order.
240V incandescent light bulb is the most sensitive electric thing I would attach to that as test load.
And would want to have fire extinguisher nearby and some metal platform under it when next time connecting it to wall.

Even this branded cheapo would be better.
https://www.overclockers.co.uk/cors...nze-power-supply-cp-9020209-uk-ca-25b-cs.html

Mcnumpty2323 · 15 Feb 2020 at 23:47

heton said:
Ok ,just connected the green to a black and psu fan works....so not psu?,thanks for that tip....hmmm so what next to test?

That test though it's useful
only confirms
The psu isn't dead
Which of course is handy to
Know
As EsaT has said it doesn't test
Quality of power delivery
Once psu is under some load

Quartz · 16 Feb 2020 at 00:56

heton said:
I checked plug fuse and also took cover off psu to see if it had a fuse...which it did but was ok also.

Be VERY VERY careful poking around a PSU. The charge stored in the capacitors can kill you.

Delta3D · 16 Feb 2020 at 01:18

Best bet of testing the PSU is to check the voltages of each pin on the 20/24 connector.

Sometimes a dead PSU can still spin the fan.

If you have a multimeter, test using Volts DC 20, black into a ground pin (doesn't matter which) and red into each of the ports to check they correspond closely to the following values on each pin.

D4Yi_74goPBywuQQElNRMD9ulNcDjX6uXSvAtMizcV15SVBFdxbc_K2VuDA8da__t1faOYdeblWLUmV9Vx4drRdwulyiKwzSQ1W2OA4_YpZ9O0ai9OmV_yLamb9o7Q

If they all seem fine, I'd recommend leaving PSU unplugged from PC, and the CMOS Battery removed for ~12 hours and then put the CMOS Battery back in, wire up PSU and test. Sometimes there can be a residual charge stopping the PC booting weirdly enough. I have seen this happen countless times and simply letting it sit with no power source for 12 hours generally resolves unless the PSU is truly dead.

heton · 16 Feb 2020 at 09:38

Thanks for all the helpful replies, I won't put that old PSU back into computer, even ifs it's not the fault, so will look for a new one on the overclockers site.....under a £100 would be nice.
CJ

heton · 16 Feb 2020 at 11:25

Checked psu 20 pin connector with multimeter, all voltages are ok.
Also change motherboard battery....nothing

Grimley · 16 Feb 2020 at 11:33

You dont have to spend that much:

My basket at Overclockers UK:

1 x Bitfenix Formula Series 550W 80 Plus Gold Power Supply= £66.95

Total: £77.45 (includes shipping: £10.50)

or if you want less unused cables:
My basket at Overclockers UK:

1 x Bitfenix Whisper M Series 550W 80 Plus Gold Modular Power Supply= £82.99

Total: £93.49 (includes shipping: £10.50)

heton · 16 Feb 2020 at 11:38

Thanks ,I'll order one of those .

heton · 16 Feb 2020 at 13:33

Ok,I was lucky to borrow a brand new power supply from a friend...computer still not turning on.

for some reason I unplugged 20 pin connector and put paper clip in green and black, The 4 pin power connector from psu was left connected on board,I then turned power supply switch to on and computers fans started running including cpu fan ,but with 20 pin connected..same fans don't turn on.
Computer on/off doesn't turn fans on/off with 4 pin ps connected.
So the question is..what's next to try.
CJ

pastymuncher · 16 Feb 2020 at 14:30

Your cheap and nasty psu may very well have killed the motherboard and/or other components. Never ever skimp on the psu.

heton · 16 Feb 2020 at 16:44

I think you could be right
pastymuncher....but if you think the one I used is cheap and nasty.....I googled the Justop 500w psu that I got a lend of to try.....it's on Amazon for £19...wtf