I have a peavey vk 212 amp, now the standard pedal to the amp to boost and change channel was working fine untill about 6 months. I started to get intermitent problems with the channel not changing and sometimes the boost pedal working and sometimes it wasnt. I thought nothing of it and asumed it must have been a fault with the pedal, i bought a new pedal yesterday, tried it and it doesnt work either. If i hit the channel/loop switch it doesnt do anything at all, if i hit the boost switch then the green LED lights up but it doesnt boost the sound at all.

Anyone know how i can try to fix this please?

I had the same problem, I even had a big gig once where at a certain moment I could change channel, man that suckd.
I never really solved it though, I sold the amp the day after the concert, my band was starting to get my and we couldn't really afford shit like that.
I dpn't think it had anything to do with the amp though, I sold the footswitch to a guy with a 6505 looking for a switch, he had the same problem with the switch.
well ive replaced the switch with a brand new one and i still have the same problem
Maybe there is something wrong with the insert jack that the footswitch plugs into.

You could also try cleaning the jack with contract cleaner in the event that it is dirty.

You could post in the VK thread and see if anyone has any ideas.

There was a mod to these amps that helped the switch delay problem but it sounds like you have a different problem.