[RESOLVED] PSU/Power Switch?

skippie

skippie

Junior Mumbler
#1
Im trying to fix a power problem on an emachine T3828. Yes, I know the best thing to do would be to just set it on fire and buy a new computer but it is not mine.

It had a Bestec 250w PSU. I know about the issues with this brand and how when they go, they can take the motherboard with them. But I'll worry about that when I hopefully get the computer to turn on. I replaced it with a 300w I took from another box, which was working, still is, I paperclip tested it and it powers up the computer I took it from. When I put in the emachine, the standby power LED on the board comes on but it wont power up, nada. Im thinking power switch, but it doesnt look like fun to get to it. I exposed it to the point where I could reach the piece that that the switch pushes in and it seems to be physically acting fine. If anyone has any suggestions other than dropping the whole thing from the 10th floor into a wood chipper, that would be great. Thanks!
 
grover

grover

Ex pert
#2
Are they both ATX power supplies? Were the PSU and power connections the only ones you changed? I'd check the connection on the power switch leads and make that that's not the culprit, and double-check to make sure the other connectors are fully seated.

After that, wood chipper might be the best idea...
 
skippie

skippie

Junior Mumbler
#3
Its a Power Man FSP250-60GTA ATX P4 250W. All the the connections are seated good, didnt change any thing else.

Now wheres that chipper...
 
skippie

skippie

Junior Mumbler
#4
Both connections to the board are snug, see pics. Anyone know the least painful way to get to the power switch on this machine? Doesnt look easy.
 

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DanceMan

DanceMan

Procrastinating Member
#5
It would seem you want to bypass the front panel switch by getting at the appropriate pins on the ATX psu connector. If that was your intent, I'd try pushing a slim but stiff wire with bared ends down into the 20/24-pin connector beside the existing wire. You already know that's the green and any black from your paperclip test.

But if you suspect the front panel switch has gone south, you'd want to get at the front panel connections. Does this board use one big multiconnector with no pins identified in any manual or more conventional labelled pins intended for small individual connectors?
 
DanceMan

DanceMan

Procrastinating Member
#7
Probably those. Trace the wires back and if they go to the power on switch and the led's, those are the ones I meant. If the front panel power on switch has become defective, you could tell by pulling off the connector and momentarily touching the two pins on the motherboard with a jumper (if it fits -- it does on a regular non-oem board) or a screwdriver, being careful not to touch any other pins. You would know which pins by following the wires from the power on switch. If that does not start the psu then the problem is likely in the motherboard.

By the way the FSP in that Powerman psu model number means it was made by FSP. It should be an inexpensive but reputable psu.
 
skippie

skippie

Junior Mumbler
#8
In the 299 photo, the connector facing the camera is a 4 pin. One of them is empty and the other 3 are occupied by one of the white wires, the black and green wire. Behind it on the right is a 2 pin with the red and a white. Behind it on the left are two unjumpered pins. All 3 pairs disappear into to the riveted case behind the power switch. Which 2 pins should I jumper?
 
DanceMan

DanceMan

Procrastinating Member
#9
I would pull off the front plastic bezel to identify them, assuming that you can't find a manual for the board or computer that tells you.
 
Technoplume

Technoplume

Member
#10
Do not put a jumper on the 2 pin, this will make a constant current on the powering logic module. And it'S not desing to do that, Just use something metal to short the 2 pin to power the board. Once it start remove it. I use a screw driver for that. what you could do also is use the reset switch has a power switch since there both the same. Has a temp solution. If the board does not power, disconnect all drives and option cable like extra USB etc. If it still does not boot, you could try a new cpu if you have one available. But At that point you get few solution. 1 the cpu is dead, 2 the mobo is dead. Witch lead the good PSU protection circuit to not power up because the circuit does not close on the mobo or cpu, OR it short circuit some were.
 
skippie

skippie

Junior Mumbler
#12
What I said in #8 was wrong, facing the camera, thats two (2) pin connectors not a single (4) pin conector. I removed all 3 connectors to jumper the pins and low and behold they're marked on the other side. gr & wh is the power LED, r & wh is the HDD LED and wh & bl is the power switch. I jumpered the pins for the power switch and nada. Power to PSU, standby power LED on.

@Technoplume, if that doesnt rule out your suggestion, I dont know which pin is #2
 
Technoplume

Technoplume

Member
#13
Hummm, I think it'S dead Jim, But I have seen 1 PSU in my PC year that had Surge protection. The way to reset the fuse was build in the 220/120 volt selector. Unplug it and just switch it to 220 and back to 120. Try Again !

Last would be usual that you probably did, Unplug all dvd, HD, remover add in card etc. Put the minimum hardware in it. Drop to 1 Ram module, and try to boot. Again if there is nothing, it does not look good.

IDK if this still applies to new CPU. But remove it from the MOBO if u can and take a sniff at it, if it smell like burn wire, it might have overheated and is defective.

I don't think I can help you more on this after all those test.
 

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