Working with tsop flash

[Steve Gehlbach]

Kevin O'Connor wrote:

> 
> Has anyone had any experience with removing a surface mounted flash TSOP
> part, and replacing it with a ZIF socket? 
> 

I am an experienced solderer but with a bad case of middle age eyes.  I 
do have good equipment, a zoom microscope, hot air solder/desolder tool, 
Metcal soldering iron.  Here is a link about replacing the TSOP with a 
ZIF, by Andrew "bunny" Huang of Xbox fame: 
http://www.xenatera.com/bunnie/proj/anatak/xboxmod.html.

I tried this, and it worked (for a while), but here are the problems. 
The TSOP chip itself is so delicate, all you have to do is drop it on 
the carpet, and it will bend the pins.  This requires a few minutes 
under the microscope to straighten them out.  Getting it to make contact 
in the programmer requires patience, one little pin out of place, and it 
won't program.

Removing the TSOP is the easy part.  The ZIF socket is very difficult to 
solder in, because you don't have good access to the pins, they are 
under it.  And the socket material melts at solder temperature (or just 
above) so it is easy to melt the socket with the solder tool as you 
solder it in. Further, unless you use glue, the ONLY thing holding the 
socket on the board are the surface mount traces, which are tiny.  After 
a few insertions, the mechanical forces tend to lift traces.  I 
eventually pulled up a couple of traces from the forces of removing and 
inserting the chip in the socket.  The only way I saved the board was by 
unsoldering the socket, soldering in the chip, and running a couple of 
bridge wires to patch the broken traces.

Others may have had better luck, but this was my experience.

-Steve