Mesa Boogie MARK III

[angelothewolf]

Hi there, im with a mark III on the bench

it came with a 10A fuse on the socket for start.

One of the 6L6 tubes (V7) are glowing blue when standby switch on, and start to glowing red, and red, and red!

on Pin 3 i got 405 Vdc.
on pin 4 430 Vdc.
on pin 5 (bias supply), i got -22Vdc on V7 and -56Vdc on V6

now when engage standby on, bias voltage on V7 pin 5 goes sudently to +3Vdc ( bias V on V6 remains on -56V). So, im needing a little help with this one, the tubes are not the problem!

thanks!

[g1]

The coupling cap between the phase splitter and the grid of V7 may be leaky.

[angelothewolf]

The coupling cap between the phase splitter and the grid of V7 may be leaky.

... and that was the problem

i was getting a wrong mesure on that one... pffsss what an idiot.

thanks man!!