Hey guys,
I just got a Mesa Boogie Mark III Coliseum 300 Blue Stripe head.
There was a loose capacitor inside the amp.
The picture of the capacitor:
http://i5.photobucket.com/albums/y151/shredentz/capacitor.jpg
Info:
AM, 3300uF, 16V, ROK 8852, AGR 85°C
The board seemed to be fine though...