FIXED A CARVIN MTS3200 COMBO...

[BAD RONBO, KiLLeR DWaRfS]

just repaired a 1996 carvin mts 3200 combo for an automotive customer of mine. he hadn't used it in three years as it made no sound, and when it was working, it had scratchy pots. i told him to leave it with me and i'd investigate . upon start up it almost took my head off it was so loud ! i thought he was lying to me until i took it apart and there was no sound. i sensed no heat coming from the 6L6's which should be frying eggs at this point. i grabbed hold of the tubes, and to my amazement, were luke warm to the touch, as i should have left turkey skin on the tubes from my hands,but the heaters were all working .

i decided to do a wiggle test after downloading the schematic from the carvin site,on the components in case of a loose solder joint before pulling all the tubes out to do a signal trace on my scope. as i touched the top of various parts, i came across a 350 ohm 10 watt cement resistor on the power supply. as i touched it the tubes came alive. one of its leads was broken on the non-trace side of the circuit board where it passed thru to the trace side. it could not be repaired as this was the flat metal stand off leg type and not the axial thin wire. i did a search for this component, but could not find one. i contacted carvin and they were very helpful in finding me a part number and sent one out to me. when i received it, i noticed the overall width of the leg stance was less than the original stance. as the legs could not be bent to accomodate without fear of breaking them, i decided to drill new holes thru the circuit board inside of the originals, and soldered the new part in. amp now works fine.

the pots were sprayed thru the casing hole with radio shack pot cleaner/lube. worked them for a bit, and now they are silent. he came over my house and shred my les paul thru it and was very happy with the results. i told him not to pack pedals and things in the back of the combo as he might rip a speaker cone.

total charge with the resistor, replacement set screw for a knob, one knob, the spray cleaner and labor was a hundred bucks.