Syncrowave 350 high no frequency in start or continuous scratch starts fine

[95ram12v]

Turned my Syncrowave 350 on today and when going to strike and arc I have gas flow but no high frequency. When checking settings on the machine, there is no high frequency in either start or continuous mode. occasionally when pressing the pedal or switching the output control to panel there will be a brief buzz from the high frequency contacts, but then it stops. The spark gaps are set to .008". It will scratch start on DCEN and it welded SS perfect. I located the three relays located behind board 052-790 on the left side of the machine looking down from the top. When the pedal is pressed the center relay cycles, the bottom one does not move, and I can't tell if the top one is moving as the body is red. There does not appear to be anything burnt on any of the circuit boards. The high frequency switch on the front panel checks fine with a multi-meter. My machines SN is JJ407296. Any insight into what to check next is greatly appreciated. open circuit voltage as shown on the front panel is ~60-70V when the pedal is pressed.

Thanks,

Ethan

[1997CST]

Here's a start.

[MasterKwan]

About the only reason I've been sort of hankering for an old machine like this is that I can fix it at home...