Mark III problems. Its gone quiet!

[timmyc]

I've got a simulclass Mark III Blue Stripe head. It was working fine the last time I played it. A couple of days later, i turn it on, let it warm up and hit the standby. I can barely hear it, and no matter how high you turn the master( which is normally no higher than 2.5) it doesn't get any louder. Tried different speaker cables. Tried different cabinet. Tried different signal path. Nothing changes. The amp hasn't been moved since it worked last. Any suggestions. By the way, all of the power tubes are glowing the same.
Thanks
TC

 

[JOEY B.]

Remove ANY cables from the effects loop, make sure your guitar cable is a known good one. Have you tried different guitars? An input jack that will not "un-ground" when the plug is inserted will cause a volume issue, as well as a bad V1 or V2 preamp tube. Switch to the rhythm 1 channel and EQ OUT for all your diagnostics at this point. Make sure that your Treble, Bass, and Middle knobs are not ALL set to "0". Good luck.

 

[timmyc]

Yeah i tried different guitars, and tried switching channels. I will look to the tubes next, and possibly remove the input jack to see if something is up with it. Thanks

 

[swbo101]

Check your V1 pre-amp tube..try swapping that out with a brand new one.

 

[timmyc]

Thanks guys, it was a bad V1 tube
East fix, thanks again!