[TUHS] PDP11/34 boot problems, here i am again :)

[Gooijen H]

"asbesto" wrote:
> 1) a 74LS175 chip named E15 on our schematic diagram, that seem
>    phisically BROKEN on an edge (there is a fessure on the plastic
>    DIP package). i can't change it now because i don't have a 
>    soldering station here to do a nice job, but looking the chip i
>    think it may work...

I never remove IC's in *one* go. The chances that you damage the
multi-layer board beyond repair are real. This is what I do.
I use a dremel tool (small motor with sharp rotating blade) to
cut the pins of the IC one by one.
Don't use a cutting tool to cut the pins because the side force
might push the remainder of the pin through the solder joint
thus damaging the board.
After you have cut all the pins the IC just falls of the board.
Now, you can use a fine hot soldering iron and remove the pins
one by one use a pair of squeezers.

  good luck with your repairs,

- Henk.