Vox Night Train NT15C1 turns its self off

[Rei]

Hi everyone.

I have a relatively new Vox Night Train NT15C1 that has not seen a ton of use, But a couple of months ago it started randomly turning itself off.
I turned the amp on for the first time in a while today and it took about 20 min for it to happen again and from then on it takes about 2-3 min after I turn it back on to shut down again.

I noticed that the small fan at the back isn't turning on so it makes me think that this problem is a safety feature built into the amp to keep it from overheating.

Are there any amp techs on here who has experience with the Night Train?

I'm located in Sydney.

Thanks!

[SoulFetish]

Hi everyone.

I have a relatively new Vox Night Train NT15C1 that has not seen a ton of use, But a couple of months ago it started randomly turning itself off.
I turned the amp on for the first time in a while today and it took about 20 min for it to happen again and from then on it takes about 2-3 min after I turn it back on to shut down again.

I noticed that the small fan at the back isn't turning on so it makes me think that this problem is a safety feature built into the amp to keep it from overheating.

Are there any amp techs on here who has experience with the Night Train?

I'm located in Sydney.

Thanks!

If there was any kind of safety feature built into this amp, it would show up on a schematic. Could you track one down and post it?

[Rei]

https://music-electronics-forum.com/...8&d=1528923894

Here is a link to the schematic, Thanks!

[Jazz P Bass]

Be aware that this is certainly Not a 'simple' amplifier circuit.
The Power On is a mastery of confusion in itself.

Please define 'shuts off'.

The total power to the amplifier?
The sound from the speaker?

[nickb]

The fan is fed right off the heater supply so it the first thing to check is power to the transformer primary. So, when it fails, check the ACV across the primary, the pair of thermistors SG1 and SG2, across the power switch and the fuseholder. I expect you'll find low volts on the primary and a lots on one of the others. The one with the big voltage will be the problem one.