On Tue, 25 Nov 2008 10:38:45 +0000, f825_677
wrote:

Archimedes' Lever wrote:
On Mon, 24 Nov 2008 23:01:01 +0000, Eeyore
wrote:


Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:
You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..
If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.
Isn't that a PGA? Hard to cut the pins.
Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

If it is a ceramic package, that is not far from the best way to remove
it.

I would: Heat the PCB up a couple hundred degrees F, then heat the
ceramic chip package body up with a high temp heat gun, while inverted.
A heat gun on the bottom of the board should cause a near instant reflow,
and release of the chip.


And all the other SMT devices will fall off the board as well

WRONG!

A 150 degree F assembly is NOT at solder reflow temperature.

- would right off the board

WRONG! You PRE-heat the PCB. You only heat to reflow temp, the IC
chip you are removing. D'OH!

its a £1050 exchange PCB from Sony, but to buy new is £11,600, the whole mixer at purchase
was just over £300,000 its not a cheap piece of equipment,

Yeah, and you are not very brainy to think that someone would tell you
to reflow the entire board. Learn to read. Then learn how to properly
comprehend what you read.

but then a lot of broadcast kit
is expensive and needs special knowledge to be worked on.

No. It needs a proper technician. Nothing special about that. Just
educated.

I worked at General Instrument. I know about racks that cost $2M each,
and the broadcast industry had to buy our gear.

I saw one of our junior engineers employ your method

No, you didn't. Obviously, since you have a bent ****ing perception of
what "my method" is.

- I prefer my guys to use time and
patience over speed and probable damage.

You're a goddamned presumptuous idiot. The method I described IS how
one removes a part from a board. You need to learn about heat sources
and sinking. In the case I described, the heat is applied to the IC
chip. So, what gets damaged?