Where now?

[Bo Nalls]

Daughter brought her dead PC home over Xmas for dad (me) to fix. She said that "it just stopped working" and sure enough, when plugged in, absolutly nothing. First check the fuse - no fault there. Thinking that the power supply had died I grabbed one that came out of my own machine last month when I upgraded and swapped it for her 'dead' one. Power on and still nothing.

Hmm, let's try another power supply. Still nothing. OK, maybe the mb has died? Grab the one that came out of my system last month, swap it for her old one and still nothing!

So, having taken known working components from my old system (power supply, mb, RAM, graphics card) the PC still fails to do anything. No lights, noise, fan - all dead as a dodo.

This only leaves the power button in the case and, as I don't have a spare one, I'm now stuck. I did have a look at the power/reset connectors/cables/buttons and all looks visually OK but without a meter in the house I'm unable to fully check. Before I invest 25 beer tokens on a new case can anyone think of something obvious that I've missed.

[BigEndBob]

Seems like the 'obsolesence time bomb chip' has kicked in.
Give up now and save the frustration.

I had similiar, replaced every component twice over from other computers i knew had worked well in past.
No combination of power supply,ram,hard drive,motherboard or cpu would work.
Ended throwing the whole lot away and started a new.
Might be able to recover data from the hard drive.

Could try bridging the two pins the start button is connected to.
That would illiminate the button.

[green granite]

Sounds as though it is the power button, as BigEndBob says short out the contacts and see what happens. (a paper clip can be used to insert into the plug that goes onto the switch but wrap tape around it to prevent shorts.)

[rans6andrew]

I understand that the power switch is no more than a shorting link. You could try tracing where the wires that go to the switch arrive at the psu and just link (short with a paper clip?) them together. Do this close enough to be sure that there is no possibility of there being a fault between the point that you link and the actual psu. I also understand that there is only a few volts on these contacts so you don't need to worry about serious insulation here, just tape it up to stop it touching anything.

Rans6.....

[Bo Nalls]

Ok, so I tried shorting the power button with nil effect. I then put back the power button connectors onto the mb and all now works correctly :confused: I don't know what I've done, apart from disturb lots of cables/connectors, but who cares, it's working.

Thanks for your help folks.

[seacue]

Maybe a bad solder joint for board-mounted part of the connector??? Wiggle things. Maybe it will quit again.

Almost 40 years ago I built a computer as a hobby project. It ran the PDP-8 instruction set. The only reasonably-priced core memory stack I found was surplus from an IBM-1620. When unsoldering the remains of the cables which had been cut, I discovered that three of the wires were just stuck in terminals and had never been soldered. It became obvious why the unit had reached the surplus market :)

[Nightrider]

Check the mains cable from the wall to the power supply. Had this 2 times in my live....

[Aerouk]

Happened to my laptop last year, tried everything (incl replacing hardware in the system) and nothing worked.

Called it quits and sent it off for recycling.

[Bo Nalls]

Ok, the plot thickens. I've worked out that whenever the front USB ports are connected to the mb the system refuses to boot. Remove cable & it boots OK. However, it now seems that all USB outputs from the original & replacement mb are now dead! I assume that the front USB has shorted and fried some components on both mb's. So it seems I'm left with 2 boards, both working OK except for no USB outputs! I could go and buy another mb/cpu but I'm thinking instead about using a PCI extension card with USB outputs. The question is though, will this still route through the mb USB circuits. For about £10-15 unit cost I suppose it's woth a punt.

Oh, how I hate PCs!

[stickyb]

are you sure the usb is u/s? it couild be a short in the usb connectors in the case drasgging down the psu and therefore stopping the whole thing powering up. Check if he usb will work wihout using the cables to connect to the front of the case.

[frostbite]

Also, check to make sure that no part of the case is touching the underside of the mb.

Some cases were provided with spacers where this was a known problem.

[mad_jock]

Have you tried reblowing the BIOS? Or pulling its Battery for half an hour.

Its always worth a punt in these situations.

I suspect you might have a rogue usb device which is doing things.

It might also be worth a punt to try and boot from a live OS linux stick. Then at least you know its hardware and not a software issue

[Saab Dastard]

I could go and buy another mb/cpu but I'm thinking instead about using a PCI extension card with USB outputs. The question is though, will this still route through the mb USB circuits. For about £10-15 unit cost I suppose it's woth a punt.

No, it is independent of the physical USB wiring in the mobo.

Providing of course that you don't connect the internal USB output on the PCI card (if present) to the case USB ports!!

SD

[seacue]

Doesn't a "live Linux stick" require a working USB socket? If so, that wouldn't work if the USB is sick. OTOH, a live Linux CD should be useful. Knoppix??

seacue

[mad_jock]

Thats why it shows its a hardware problem not a OS.

Have to agree it sounds like the sockets are shot. Now it just depends if thats fryed something or just corrupted the BIOS.

The pci card sounds like an option though. If the BIOS is corrupted you might still have issues.

[Bo Nalls]

Thanks for the ideas folks. Things are on a general hold now until tomorrow when the local PC shop opens. I'm going to give the USB card a go to see what happens.

stickyb

are you sure the usb is u/s? it couild be a short in the usb connectors in the case drasgging down the psu and therefore stopping the whole thing powering up. Check if he usb will work wihout using the cables to connect to the front of the case.

Done all that. PC fails to boot with the USB cable attached but boots ok when disconnected. However, all of the on-board USB ports seem to have died now?

frostbite


Also, check to make sure that no part of the case is touching the underside of the mb.



All spacers fitted but worth a double check.

mad_jock

Have you tried reblowing the BIOS? Or pulling its Battery for half an hour.


No, but i'll give it a go tonight.


It might also be worth a punt to try and boot from a live OS linux stick


Not familiar with Linux, nor indeed do I have the s/w.

I'll report back later with any results

[mad_jock]

don't worry about the linux then.

Make sure you don't have the connectors attached when you reblow it

[green granite]

Too much swapping things about, put back to the original configuration then put the wires back in the CORRECT places, I suspect you have a connector either misplaced or misplugged.

[Bo Nalls]

New PCI 6 port USB card installed, front USB ports disconnected from mb and all working well :ok: Thanks for all your help folks, time to give the PC back to my daughter now and settle back and await her next crisis.