Need Randall RT 50 schematic

[Dehn]

Hello All,

I'm working on a Randall RT 50 with no sound from the overdrive channel.
The Clean channel works fine, all tubes have been deemed good and all high voltages are on the tubes.
Anyone have this schematic?

Regards
Dehn

[Jazz P Bass]

Schematic: http://www.echostar.pl/~zelman/RG50TCSchemat.pdf

[Dehn]

Thanks Jazz P Bass, for replying to my request for a RT50 schematic, the RG50 schematic is quite different then the RT50.
I phoned Randall and they said they didn't have the schematic, as Korg was the builder designer?.
I talked to Korg who said "We don't provide service info to unauthorized service people"
Anyone have this?

Many thanks

[Enzo]

OK, so all tube heaters are lit? Both sides on the dual triodes? And ALL pins 1 and 6 have B+? ANy of those look really high? And look at pins 3 and 8 for cathode voltage, any sitting at zero?

Apply a steady signal at the input, look at each plate. Signal at all? Make sure to toggle channel;s back and forth in case. There could be a cathode follower stage, be aware of that.

Listen for background sounds, on the dead channel is ther background hum or hiss? And if so, do the volume and tone controls affect that sound?

[glebert]

Maybe a channel switching problem like a relay not switching?

[Dehn]

Thanks Enzo fopr replying, this amp has signal all over the place, all tubes are lit.
the "clean channel" works fine, its the "lead channel" has no sound.
Both channels are really the same components just re configured with a lot of relay switches and such.
The amp owner decided to return the amp to the store, they'd said its most likely a bad tube which of course it is not.
Thanks again Enzo.

Dehn.