Hello all
I have just started playing again after almost 20 years of not touching any of my guitars. I've been playing mainly my Eko acoustic, but today decided to try my Fender Jag-Stang through my old, but virtually unused Park Marshall G10R amp, which I'm unable to get to work. When I plug the amp in to the mains power socket the red power light comes on but there's no feedback noise or any noise whatsoever, even with the volume turned to maximum. Likewise when I connect it by jack cable to my guitar. I have checked the open back of the amp and both the red and white cables are plugged in to their respective sockets correctly and there's no visible signs of wiring damage. In fact, the amp looks brand new.
Any ideas about this?
Many thanks
Cleen the pots, the input jack and headphone jack with electrical cleaning spray.

Check dc voltage the on the secondary side of the transfromer / rectifier.

If this is OK track the signal though the circuit with an oscilloscope.

If it's not been used for 20 years then I would suspect that a component is knackered

If you don't understand this get someone who does to look at for you - you don't want to get electrocuted.