On Jan 14, 5:20*am, John Rumm wrote:
On 14/01/2012 03:32, NT wrote:



On Jan 14, 12:21 am, *wrote:
In , John
*writes

I was toying with doing a wiki article on component level repair of
electronic stuff, since there seems to be so much otherwise decent kit
that dies these days for silly reasons like failing capacitors etc.

A few random thoughts - more to follow

Repair would entail correct diagnosis of the fault

exactly, and thats where ukdiy often falls down, and beginners cant
generally do it on their own.

I don't think that anyone is suggesting detailed fault finding
techniques for digital electronics.

any fault finding for any electronics would be a move forward for the
beginner

(which while not actually a massively difficult task with the right
equipment, its very easy to find yourself twiddling knobs on several
hundred grands worth of it in the process, which tends to put much of it
beyond most folks DIY budgets)

At the simplest level, a hell of allot of kit can be saved just by
spotting the caps that are bulging and spewing electrolyte all over the
place. If you want to get a bit deeper, then you can do plenty with a
multimeter, and even relatively specialist bits of kits like LCR
component analysers or ESR meters are not that expensive.

(I don't agree that ukdiy falls down on diagnosis either particularly *-
we have some very good engineers here with plenty of experience in
relevant fields. That does not mean that all contributions or all advice
will be spot on, but its no reason to write it off either)

A problem I see here too often is a series of people simply taking
wild guesses. Its an approach that simply doesnt work often when
you're faced with an electronic system using 100s of parts.

For beginners to electronic repair I'd suggest
1. getting a multimeter
2. understanding that both power and signals flow through the circuit
stage by stage
3. Using the meter to spot where power or signal fails to be there,
thus narrowing the fault down to a specific small area of circuit.,
usually. I say usually as eg CRT TV PSUs can be extremely interlinked
with other parts of the tv.


NT

plated through holes, once the component lead is removed, if you then
reapply solder to the joint and can clean the hole out better with a
solder sucker

you can, but I've never seen teh point. Just heat the hole and push
the component lead through.

That works for many boards, but not all. In some cases a typical iron
delicate enough for the size of task can't supply the heat on a
multilayer board. That's where the hot air systems work well, either to
temper an area of board to give the iron a chance, or more typically on
their own just to reflow the obscured hole so it can be sucked clean.