Ok, I'll try to find a fan tomorrow and try it out.
BUT I did come across this (you may have seen the comment on my yt video about someone suggesting it was a switch regulator heating up)- http://acapella.harmony-central.com/showthread.php?2619108-Bugera-Channel-Switching-Fix
It seems like their problem is overheating aswell, and even though the guy on youtube said it only caused problems when the footswitch was connected, I think this may still solve my problem. Dunno yet though. I'll try and isolate the problem to it either being a heat problem or not, and if it is, I'll go this route and see what comes of it (unless anyone on here has any other ideas.)
BUT I did come across this (you may have seen the comment on my yt video about someone suggesting it was a switch regulator heating up)- http://acapella.harmony-central.com/showthread.php?2619108-Bugera-Channel-Switching-Fix
It seems like their problem is overheating aswell, and even though the guy on youtube said it only caused problems when the footswitch was connected, I think this may still solve my problem. Dunno yet though. I'll try and isolate the problem to it either being a heat problem or not, and if it is, I'll go this route and see what comes of it (unless anyone on here has any other ideas.)