Author Topic: Computer not starting up after blackout. (Read 5566 times)

chuchuboi · « **on:** October 27, 2009, 05:39:49 PM »

after a blackout, computer doesn't start up.

i tried diff outlets on my apc surge arrest,
i tried diff main power outlets,
i tried leaving it plugged in for a few hours and then start,

but in end still nothing.

this happened previously before, and i thought it was dead so i called APC to file a claim. the guy told me to try diff outlets on the bar and i did. the result was, the computer worked on other ones. so they said the bar was faulty and sent me a new one. now the same thing happens and even if i try the diff outlets, nothing happens.

i had a few prior problems with the computer before, such as cmos screen poping up, but that happened once and like a few months ago. then there was a few times where it would goto the windows screen, but not load the desktop. i restarted it a few times and it followed through and worked. that also occured like a few months ago and never again.

i own a p4 2.8, 1gb ram, gfx5500, 300gb hd. its about 6yrs old.

i searched the forum and looked for possible solutions, but none of the cases matches mine perfectly so here i am posting.

Computer_Commando · « **Reply #1 on:** October 27, 2009, 05:58:47 PM »

Remove the APC and plug directly into the wall receptacle.

chuchuboi · « **Reply #2 on:** October 27, 2009, 06:08:54 PM »

i tried that also. this nothing.

however, i do hear a small buzz/whistle noise when its plugged into an outlet, apc or wall. i figured it was a "charge" but ya.

stiill won't start.

Karnac · « **Reply #3 on:** October 27, 2009, 06:11:38 PM »

Any lights, fans starting up, HD startup, beeps?

chuchuboi · « **Reply #4 on:** October 27, 2009, 06:12:34 PM »

nothing starts up. no lights or beeps. the only sound is from when i plug it into an outlet, its like a buzz/humming noise, very faint

Karnac · « **Reply #5 on:** October 27, 2009, 06:15:18 PM »

See if you can borrow a power supply of = or > wattage and swap it in and see it it fires up........

Computer_Commando · « **Reply #6 on:** October 27, 2009, 06:16:08 PM »

Computer was plugged into the apc surge arrester and computer was on or off when you lost power? It's beginning to looks like the power supply (psu) is damaged.

chuchuboi · « **Reply #7 on:** October 27, 2009, 06:20:02 PM »

i was using the cpu when the power went out. it was only for like 5secs and came back on. but when i tried restarting, it dint' work. its always plugged into the apc. i tested the outlets with other stuff like light,monitor and speakers and all works fine.

my friend suggested i check if the motherboard light is on, and it is.

as for spare power supply, i won't be able to get one until maybe tomorrow, and might even need to buy a new one if anything. just wanted to confirm its the problem before spending.

Computer_Commando · « **Reply #8 on:** October 27, 2009, 06:25:51 PM »

It's not confirmed unless you can verify the buzzing is from the psu. If motherboard light is on, then part of the psu is still functional. Do you have a voltmeter and do you know how to use it?

chuchuboi · « **Reply #9 on:** October 27, 2009, 06:26:33 PM »

i have one, but not 100% confidant on how it works.

Computer_Commando · « **Reply #10 on:** October 27, 2009, 06:30:51 PM »

Quote from: chuchuboi on October 27, 2009, 06:26:33 PM

i have one, but not 100% confidant on how it works.

That doesn't do you much good.

ATX Pinout
6-year old computer is probably ATX-P4-Type.

You need to know more about the computer before you buy an new one.
Post back with Computer Make and Model Number.

chuchuboi · « **Reply #11 on:** October 27, 2009, 06:38:40 PM »

the computer was a prebuilt one, no name brand. i just remember it was a p4 2.6 or 2.8.

as for the power type, it has 2 thing connecting to the mb. 1 is a square plug and the other is 20pins. same colors as the one you gave the link to.

Computer_Commando · « **Reply #12 on:** October 27, 2009, 06:52:45 PM »

Lay the computer on it's side and remove the side panel.
You test the psu voltages with everything plugged together and on. Voltmeter probes go into the back of the plugs. Set voltmeter on DC, put probe of black lead into any Black wire and leave it there for all tests. Probe each pin that has a voltage (plus or minus) with the red lead and record the voltages. Skip pins-8 and 14.
Be careful not to short probe ends together when they are contacting voltages.

Notice the color codes:
Org=+3.3V
Red=+5V
Yel=+12V
Blk=Gnd

It appears that the +5V is OK (MB light is on), but one or more of the others (+12, +3.3) is out

chuchuboi · « **Reply #13 on:** October 27, 2009, 07:13:41 PM »

Be careful not to short probe ends together when they are contacting voltages.

what does that mean?

so i keep everything plugged. then i put the black tip into any of the black wires coming out of the 20pin plug, and then test the rest with the red wire to check the vols, excluding 8 and 14?

chuchuboi · « **Reply #14 on:** October 27, 2009, 07:17:44 PM »

when you say DC which one?

on my voltmeter, it has

DCV 10, 50, 250, 500
DC Ma .5, 50, 250

Karnac · « **Reply #15 on:** October 27, 2009, 08:51:33 PM »

Troubleshooting Computer Power

chuchuboi · « **Reply #16 on:** October 28, 2009, 10:35:03 AM »

ok so i tested the connectors and everything is 0 except for the standby power one (purple).

on the chart, its suppose to be +5, but i am getting +8.

I assume then that the power supply is dead and needs to be replaceD?

Computer_Commando · « **Reply #17 on:** October 28, 2009, 12:43:52 PM »

Remove power cord from wall. Remove all connectors from motherboard and drives. You can leave psu mounted in case. Get a paper clip and short the Green wire with one of the grounds (14 to 15 or 14 to 13). Connect power cord to wall. This should turn the power supply on.

This tests the power supply with no loads. If something else is shorted the psu would not turn on, so it could be good and something else is bad. It's unlikely, but it only takes 10 minutes.

chuchuboi · « **Reply #18 on:** January 13, 2010, 09:54:12 PM »

Sorry for late reply, was on vacation.

APC denied my claim so the *censored* with them.

Last week i bought a cheap refur cpu for my dad and i ended up ripping apart the old p3 he had. i took out his old psu and tried it on my p4.

his p3 had a 300w psu.

my p4 is using a 400w and also a atx12v wire.

i unplugged all components from both cpus and just connected the psu to motherboards.

test 1: put 300w psu into p4(broken cpu). starts up.
test 2: put 400w psu into p3(working cpu). starts up.
test 3: put 400w psu back into the p4(broken cpu). no start up.

my friend told me to use the 300w, but im scared since it doesn't have a atx12v wire, it mite screw things up. and i checked online for pricing and a new psu isn't too expensive... should i just buy a new one?

or is there some other problem i am not aware off?

patio · « **Reply #19 on:** January 14, 2010, 08:33:12 AM »

Get a new PSU...

chuchuboi · « **Reply #20 on:** January 14, 2010, 01:06:14 PM »

if thinking of getting another 2 sticks of ram for my cpu. a lil xmas present for myself..

with a new 450psu, and 2more sticks of ram, should i look into ram cooling or stick another fan into the cpu?

Quantos · « **Reply #21 on:** January 14, 2010, 06:06:43 PM »

Whenever the power goes off there is usually a surge experienced when the power starts to run through the lines again. Depending on the surge protector/UPS involved they CAN pass through. I would suggest taking the PC into a local shop and get them to test the components.

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Author Topic: Computer not starting up after blackout. (Read 5566 times)

chuchuboi

Computer_Commando

chuchuboi

Karnac

chuchuboi

Karnac

Computer_Commando

chuchuboi

Computer_Commando

chuchuboi

Computer_Commando

chuchuboi

Computer_Commando

chuchuboi

chuchuboi

Karnac

chuchuboi

Computer_Commando

chuchuboi

patio

chuchuboi

Quantos