Robyn SB-520 (858 PLL) no 7.8 reading and overheating capacitor

[Lkaskel]

Hi Gang,
I have an SB-520 on the bench doing an alignment. The radio has been re-capped. In the synthesizer alignment section I made all the way to the last 2 steps (the 7.8Mhz adjustment). I got no reading on the freq counter at TP-9 and C101 (closest to the edge of the board) was nuclear hot. I quickly made sure it was in correctly (not reversed) and it was. I shut the radio off to keep from any damage. Any thoughts why there would be no 7.8 at TP-9 and C101 is on fire? I did pull a Washington with the 858 board and verified things and I could get a reading at TP-9 and C101 was not hot.

Thanks as always!!!!

 

[M0GVZ]

Capacitor is knackered or something further down the chain is short to ground or in fact both, the former being caused by the latter.

 

[nomadradio]

If C101 is hot, then R113 must be as well. Not much that can cause this fault, other than a bad cap.

73