Died and gone to computer heaven?

[sorcerer]

Got a Toshiba Equium U400 in that's as dead as the proverbial Dodo - no lights, no fan, no drive, no sounds, nothing. Multimeter on the end of the customer's charger shows 19.47 volts and I also tried with two different chargers that I've got here, to no avail.

This laptop utilises a DC jack with a wiring harness that ends in a 4-pin plug, which obviously goes into a corresponding 4-pin socket on the motherboard. I stripped it down to just the motherboard on the bench, connected the power and I can confirm a steady 19.47 volts at the socket on the mobo.

When I've had similar problems in the past, there's usually been some chip on the board or some component that's presumably gone short-circuit because it gets very hot and there's that unmistakable smell that precedes an escape of the magic smoke, but not in this case.

I don't have the skill or the equipment to go any further. I've got 19.47 volts into the mobo but nothing's happening, so what do I tell the client - that it's definitely knackered, or do I suggest they take it elsewhere to someone who can do board-level faults? Or, have I missed something - is there something else I should be trying?

 

[SilverLeaf]

Power button? and, as odd as it sounds, check the BIOS battery.

 

[frostbyte5014]

Check capacitors. Are they swollen or ruptured? Could the the onboard power regulators. Sometimes the regulators are on a small separate board that can be replaced.

 

[sorcerer]

Thanks guys, your suggestions are the first things on my 'to do' list today

 

[Kitten Kong]

How about sending the laptop off to some place like ACI (RMA Updates).

IF there is a chance that the board can be salvaged, they will repair it, for a fixed fee.

Nothing to lose, and only the cost of courier fees to consider if they cant repair it.

 

[sorcerer]

Good idea Nige, might just do that, thanks mate.

Frostbyte and Silverleaf - All caps look to be ok (but who knows for sure) and the CMOS battery is measuring at 2.77V. Trouble is, I don't know what it's meant to be although I'm assuming 3V - can't see any markings because it's covered, as you'll see in the attached picture.

 

[mr m]

Brand new button cell CMOS batteries show around 3.25V. 2.77V is not your problem but it is getting weak.

First off I'd check all external ports (especially the USB ports) for mangled pins. Then I'd strip the laptop mobo of everything that can be disconnected. Don't forget to remove the main battery. Start with the easy to remove stuff first before you totally yank out the mobo. You might get lucky and find a bad stick of RAM or DVD drive

I keep a magnifying glass and a flashlight on the bench. You might find a burned or cracked component.

 

[sorcerer]

Thanks very much mr m, but I've already done all that and no joy.