Apple IIc woes -- HELP!

[jimr@eicon.com (Jim Royal)]

I'm hoping this message has finally reached the newsgroup.  My last two 
messages were apparently seen only by INFO-APPLE subscribers.

My Apple IIc was damaged during an electrical storm.  It seems a spike on 
the telephone line fried both my external modem and the IIc modem port.  I 
discovered the damage to the port only after purchasing a new modem.  The 
DTR line appears to work normally, but the machine locks up when I try to 
send a single character.

On the advice of a friend, I replaced one of the two 6551 chips on the IIc's 
motherboard. These chips are responsible for Port 1 and Port 2 serial I/O.

The transplant was successful, but the problem didn't go away.  According to 
the Apple IIc Technical Reference Manual, there are two other chips in the 
IIc responsible for serial I/O -- one for incoming signals, the other for 
outgoing signals.  Should I replace both?  What else could I do?  I don't 
want to replace parts at random.

Needless to say, I dismissed a motherboard swap from Apple Computer as a 
hideously expensive proposition.

Any suggestions?

 Jim Royal
 jimr@eicon.com