DT50 Head - Power light turns on briefly, then goes out

[tamino]

Last time I played my DT50 head was about 3-4 years ago. It was working fine then. It's been powered off since then and stored inside my house. It hasn't been disturbed in any way.

 

A couple days ago, I tried to power it up again (in standby mode, of course) and it exhibited the following behavior:

 

- Power light turned on for a brief moment, then quickly faded out.

- None of the white lights on the front panel indicating what channels and modes are selected lit up.

- After a couple minutes, I switched out of standby mode and a bunch of noise came out of the speakers (a single 8 ohm cabinet plugged into one of the 8 ohm outs). I could not hear the sound from my guitar when I strummed it. I also previously verified the guitar and cable are working properly.

 

Other info:
- Both externally accessible fuses were/are good (tube protection + IEC fuse).

- Power tubes were glowing.

- It repeats the same behavior every time I power it on.

 

Anyone have any ideas what could be going wrong? I don't think it's the output transformer (a common issue with these amps, apparently) because the fuses are not blowing.

[Brazzy]

There are 2 more fuses inside the chassis but I never had problems with them to my knowledge. Maybe a bad connection somewhere, sitting over time can cause problems such as a bad capacitor/'s.

 

Maybe you call Line 6. You may have one of the DT's that needed fixing due to manufacturing issues. They might still fix it under warranty. Who knows, you can ask, what's the worst they can say? No?

[JHSTone]

I've had an issue similar to this ever since I got my DT50 212, except, on mine this only happens after I have been playing it for a while. When I turn it off and try to turn it back on the only light regarding topology, class, and pentode/triode that comes on is the class indicator and it goes straight to A/B. I hear the noise floor, but none of the controls are functional and there is no guitar signal. I have been meaning to ask Line6 about this, but I haven't yet. Definitely need to because my warranty is coming to an end, but other than this issue, it has been working fine ever since it had the transformer replaced a few months after I got it!

[MartinDorr]

I had similar behavior on a DT25 and it was the tubes.

Don't know which one(s) because I changed them all, but they where all glowing despite not working.

If you do not have an old or replacement set, it's worth getting a backup anyway.

In my case I could hear a faint guitar signal when I switched to low power mode - I'd guess that means the tubes where not totally broken in my case.

Once you checked all fuses and replaced tubes there is nothing I know of to do but to bring it to the shop unless you know how to dig deeper into amp electronics.

Good luck