[OLD PEDAL REPAIR] Guyatone PS-004 Flanger not working

[Mark Hammer]

Doesn't have to be a GR.  Could be any 2SK30.  Could also be a J113.

[Scruffie]

There's a problem with the MN3101, pins 2 & 4 should be approx half supply.

[Fender3D]

....
Anything obviously weird?

IC1 pin7 should be near half Vcc, might be C13 leaking.
IC2 pin 2 and 6 should be near half Vcc and pin4 should be lower than 8.8V.
Mark suggested TL062 in IC3 position, NOT IC1...

Voltage at IC2 pin4 comes from IC4 (MN3101), as Scruffie suggested, check it...

As Mark said, don't rush looking for FET replacement, just short its outer pins....