Fender 1000 Roc Pro. cutting out, Whats Wrong?

[gem1n1]

I have a Fender 1000 roc pro that when played for a while, 30mins, the sound dies but the unit is still on. I am a newbie to this type of thing and think it has a tube. could that be the problem.
Any help would be greatly appreciated:confused:

[Enzo]

There is only one tube in this otherwise solid state amp. The tube itself barely does anything, and even that ONLY on the gain channel. No tube in the clean channel, so if the clean channel is fading out too, then it is not the little tube. But you can look at the tube and see if the heaters fade away.

Plug a spare guitar cord into the FX send jack, and the other end right back into the FX return. Does this restore the sound? If so, the return jack needs service.

Plug into the FX return with the guitar. Does THAT fade away too? Or does it remain while the normal signal path through teh amp fades away?

Make sure R116 and any other large cement resistor has not cracked its solder.