Ron wrote in message
...
N_Cook wrote:
Arfa Daily wrote in message
...
"Eeyore" wrote in message
...
whit3rd wrote:
On May 21, 2:59 am, "N_Cook" wrote:
Obviously I've come acros melting/burning, starting from bad
connection
arcing , but not this amount of damage, so am requesting other
opinions.
Burning right thru the pcb for 1/2 inch around the L pin of the IEC,
melting
of the plastic of the IEC above the burning and even the linecord
plug
Yep, ring crack around a power solder connection, generates lots of
heat.
Possible. A victim of lead-free soldering ?
http://en.wikipedia.org/wiki/Tin_pest
Note that pure tin solder degrades below 13C. Yes that's right. And
turns
to dust.
Adding a little copper doesn't stop it but slows it some but not
enough.
The EU Commission should be strung by their necks from lamp-posts for
being a
bunch of technically ignorant ****s. Why do they think lead was used
in
solder in
the first place ? For fun ?
Graham
Just what I've been saying since they first mandated the hateful stuff
....
Arfa
This is a 1998 amplifier, made in China so conventional solder ? does
not
look "volcanic" or tin-pesty dusty grey solder points on the boards.
It probly started off as a hairline crack around one of the soldered
joins, caused by repeated connecting and disconnecting. It started
'fizzling', no one noticed (or cared) until the amp failed to work by
which time there was a socking great hole in the board and a nasty
smell. It`a amazing how long a lot of musicians will put up with faulty
gear, prefering to ignore problems till the item stops working.
Doesn't really need a post mortem.
Ron(UK)
I agree that is the normal etiology and pathology, carrying on the
medico-speak. But this was a socking great burnt patch and billowing smoke
out of the 1/4 inch socket holes, that developed after sound check and
before use proper. Agreed there could have been long term, unnoticed, minor
fizzing but I've never seen this sort of damage in this sort of mains power
line circumstance.