[ICOM] 75 PRO III Smoked!

[jkolin at optonline.net]

I have a late production unit. It has the newer PA Board using MOSFETS as drivers and finals.

3 Days ago I was checking SWR on a new ant. 2/1. Key down w/100W for about 10 seconds. After a few SWR measurements power dropped to 5 W max. Then I could not go into transmit mode. After about a minute in receive mode, smoke billowed out of the rear panel from the PA compartment.

Removed top covers and found 3 burned SMD resistors. R38, R39 & R40.  4.7 ohm. All 3 are in parallel.

Anyone have problems with this newer PA board? I have not been able to find parts layout drawing that applies to this new PA board.

Thanks for all your thoughts.

Jay....