[1000mp] 75/80M Problem

[Bill Hellman]

Help!
I have an intermittent problem with my FT-1000MP on the 75/80 meter band.
After about 15 minutes of operating it stops transmitting but continues to receive. It affects 
SSB and CW.  If I turn the radio off for 15 minutes or more, it restores and I can transmit on 75/80 
for another 15 minutes. It appears that a component is heating up and opening. But, what component? 
I reseated every connector I had access to, hoping it would be as simple a fix as that. 
All other bands are normal. Any ideas or suggestions are welcome before I ship it off for repair.

Bill Hellman, NA2M