Quote from: rens on November 06, 2018, 02:16:59 PMTake a look at the schematic. When measurung DC resistance, any cap can be considered "no connection". There is no DC path between 7 and 8, so you don't have to disconnect it. 700 ohms is fine, the reverb tank seems to be ok.
Reverb: 7-8 measures around 700 ohms when connected, but I guess it has to be disconnected to know for sure?
Quote from: rens on November 06, 2018, 02:16:59 PMMy bad, I overlooked that that junction is also the input of the gain stage around Q4, so this is certainly inconclusive.
Pin 10 does hum, but I could not hear if the hum went into the tank.
Quote from: rens on November 06, 2018, 02:16:59 PMThis means that the reverb pickup and recovery amp(Q16/17) are fine.
Tapping the tank with something does give an echo to the signal, but not the guitar signal.
So there is not that much left, either driver amp TA7200P does not work or there is a broken trace/solder joint around its output/C49/R96.
15VDC at pin 3 are present?
Quote from: rens on November 06, 2018, 02:16:59 PMOk, so you should check the return path of the chorus first. Does touching one of the legs of R31 give any hum? It is the input of Q19, the switching FET. Touching it and switching the chorus or vibrato in and out should make an audible difference.
Chorus: R137 does not give significant hum when touched, some faint crackling can be heard though when touching it.
The connection from R188 to point 20 of the channel 1 PCB looks fine and measures fine.