Kustom K50 Trem/Vibe not working

[El Músico Loco]

Hi,
I was wondering if anyone has any ideas where to start with the tremolo/vibe section. It is turned on/off by the Intensity knob and switched between trem/vibe by a switch on the speed knob on the front panel. I have checked the switches and they work. I was hoping someone has had this problem and knows a good staring point.
Here is the schematic,
Thanks,
Chris

[52 Bill]

Is the LFO working? Check for a fluctuating voltage at the intensity control. The voltage should change based on the speed control.

[El Músico Loco]

Hi,
I just figured it out. Someone had replaced the intensity pot which has the switch on the back with onw with a n/c switch; instead of opening the path to ground by turning the switch on it was shorting it to ground effectively turning the effect off by turning it on. Happened to have a push/pull cts pot here that will work. All in all the amp sounds great now with the new input fet and the trem/vibe & reverb all running. It is extremely quiet though it still has it's ungrounded, long original cord and I am using a stepdown transformer here in Spain to supply the 120v. Learned a lot with this one.
Thanks for the help
Chris