[ICOM] IC-207H blown UHF module--Questions

[Mike Clarson]

I have an IC-207H with a blown UHF power module. Been using the radio for A
few years on 2 meters but finally got around to opening the radio up. Trying
to figure out what happened. 

On 2 meters, the radio, if running into a bad antenna would sometimes lock
up on transmit. Wonder if this happened on UHF and cooked the module. 

On removing the UHF module, the module heat sink surface is discolored
around the output pin for 1/4 inch. Also, there was no thermal grease on the
modules--is this normal?

On to checking the PIN diodes--first check indicates they have to be checked
out of circuit--either that or they are bad. 

Of course its one of the more expensive modules--about $100. 

If anyone has gone through this, any hints or experience would be
appreciated. Thanks in advance. --Mike, WV2ZOW