OTHER REPAIR TECHNIQUES
The following are valuable aids in troubleshooting and in verifying the stability of the amp
and it’s parts.
• A plug must be inserted into INPUT 1 in order to connect the first stage's output into the
second stage. With nothing plugged into the #1 jack and with VOLUME 1 turned on, the
switch contacts are free to vibrate and may start a resonant feedback at high settings. But
this is no problem because if INPUT I is not being used, its volume control should be
turned off and when a plug is inserted in the jack, all vibrating will stop instantly.
• Look carefully at all the connections around the tube sockets, then look at all the
connections of parts and wires to the boards jacks and controls. Give each one a little pull
test with pliers while the amp is running. Knock the chassis several times with a small
hammer, it should be quiet and stable and able to withstand great amounts of shock and
vibration; it has been built tough and carefully.
• An arced out circuit board can be repaired by scraping away all carbon traces and
replacing any arced high voltage stripes with wires leading directly to the tube socket
pins. Remove all carbon from arced tube socket, or replace socket.
• Sugar residue or beer, etc. on the circuit boards must be removed to allow stable
operation.
• A 10-24 tap can be useful for straightening out damaged threads in the chassis if a
mounting screw gets cross threaded.
• When removing the grille board to get access to the speaker, back the 4 black screws
half-way out and grip them like handles to pull off the grille board.
• If speaker mounting screws won't tighten after several replacements, you can rotate the
speaker slightly to expose fresh board underneath. Don't mount a speaker with the frame
contacting any pre-amp tubes or excess feedback will result and the tubes won't unplug.
• Speaker and reverb cables are long enough to allow chassis to sit on top of cabinet to
make work and testing easy.
• Any problem you or your technician are unable to solve may be referred to
MESA/Boogie for assistance over the telephone.
5
To Next Page
Loading...
