NAD Mesa MK2C+ Help….Hum and then blown fuse

Hi

So I recently bought a MK2C+ Combo. It’s a 60w non simul, graphic model. I am in the UK and the amp was posted to me.

The packaging was good and no structural damage.

I noticed the seller had removed the 2 power valves and left them in bottom of the amp.

I reinstated these and checked all other valves were seated correctly. I powered up and left in standby for a few minutes to let the voltages settle. Turned all volumes down and powered up. There was a massive hum, with out guitar even plugged in. Then I switched off and rechecked all valves seated. This time turned on without the guitar even plugged in. Again a very loud hum and I began to turn the knobs, halfway through, no power so either mains of amplifier fuse blown.

My dilemma is to either return the amp or try to source a decent amp tech, which is not easy where i live. I am prepared to do the latter, but only if it’s not a major issue.

Any insight appreciated

You could try powering the amp up with the power tubes removed and see if the amp stays on..This will rule out any problems with the tubes themselves.
Also check the voltage selector switch on the back to make sure it's at 240v for the UK.

Monkey,
I’m no amp tech, but I have played tubes amps for a long time. There are lots of reasons amps will hum loudly and then fry a fuse. Most of the time, I’ve found it’s bad power tubes. I’d recommend verifying all the settings are correct first…make sure you’ve set the transformer to the correct wall voltage first, then make sure you’re plugged into the correct impedance for your speaker. Next, make sure you have a good set of power tubes. If it’s still acting up, “tube roll” the 12AX7s. If you aren’t familiar, that means swapping each preamp tube one by one. If these simple steps don’t work, take it to your local Boogie tech.
Hope this helps,
Brad