On Sun, 30 Jan 2011 06:22:59 +0000, Fred wrote:

T i m wrote in
:

Cheers, T i m


Get a competent technician to take the laptop apart and resolder all the
connections between the power jack and the circuit board it is SUPPOSED
to be soldered to.

We only have access to an aging ex BT trained Electronics Service Tech
here g and he carefully removed the old and replaced with new the
power socket. FWIW the original socket was showing no signs of damage
whatsoever and all 8 of it's pins were still nicely soldered to the
board.

They get a hairline crack in the solder because
that's the only thing holding the connector to the board.

Understood and board cracks were seen many a time on Plessy made
modules that made up the std 300 Baud BT PSTN modem sub modules back
in the day (Modulator unit, demodulator unit, filter unit, control
unit and PSU unit etc). GEC, STC and Marconi generally used fibreglass
boards so were much stronger so less prone to cracking.

These cracks
can be so thin you need a jeweler's loupe to see them, if you find them
at all.

Understood and that's exactly what I was viewing them through (I used
am illuminated magnifier when I was de soldering and cleaning).

Resoldering the connector to the board fixes the problem.

Not in this case though I'm afraid but also has for me on many
occasion (there were 5 different sockets in the last batch I ordered).

The competent technician will, of course, load test her AC power supply
before tearing into the computer, bending and pulling hard on the plug at
the computer end to make sure the wires inside the plug and cable have
not been broken, another common source of intermittent power,

Yup and done.

say it was powering the computer so that's probably not the problem.

Not in this case I don't think and another (supposedly working) PUS
was substituted with no change in the symptoms).

There is a switch telling the computer the power supply is plugged in on
many models moved by the power supply plug and that switch's connections
may be intermittent.

Again, looked for but none found (and if it were within the DC socket,
would have been replaced with the socket).

FWIW it is understood that there were two laptops on a sideboard and
laddos Mum picked up hers and thinking the were free of each other,
'pulled his laptop along a bit'. If that were true (and I have no
reason to think otherwise) I am inclined to thing the most likely
thing that could have happened would be the unusual temporary
disconnection of one of the connections causing a spike or some such
because the plug / socket combo were slightly loose (after two years
or very regular use and daily movement). But they were only slightly
loose (I use and have seen much worse myself) so I'm not sure.

We will see (hopefully).

Cheers, T i m