When to know a board is dead

[enigmatic]

as you might have seen my many threads about my laptop, well heres another

im just wondering how do you know when a board is completly dead, like no way back for it at all as i've been reading a few post of boards about ppls problems with thier laptops and the fact that their power circuits have died.

once that circuit dies it is dead forever?

[arneson]

Re: When to know a board is dead

I say, first, is a replacement available?
At what cost? How much could you make in one hours work.
How many hours have you spent screwing with the issue? research,dissasembly,head scratching?
Is there sentimental value to this item? ie, how much do you love it, hate it?
I have a hard time spending even modest amounts of money on old laps when new ones are so increadably cheap.

But I still do.

[Rainbow]

Re: When to know a board is dead

I consider board dead when the chipset is dead - either visibly (a hole burnt in the middle) or "only" shorted - either partially (powers up but goes really really hot immediately and does not work, of course) - or completely (does not power up because of PSU protection, powering from "soft" supply reveals if it's chipset or not). Yes, chipset can be replaced too - but the tools are expensive.
Also heavy PCB damage is lethal - such as MOSFETs burnt through PCB, deep and wide scratches and cracks.

[enigmatic]

Re: When to know a board is dead

well there are a few chips that i've been told are FET that the solder joins seem burned and these are directly linked to the power circuit? the board shows power light and battery light constantly on even without battery, and when battery is inserted it flashes to show charging but its actually not.

hmmm interesting stuff, dont actually think the board is completly dead so off to get the chips out and replaced i guess, but how do i find out whats causing them to fail, can i run any kind of test to ensure once replaced they wont die again?