Death of the DSL40CR..

[Devin]

I'm a newbie, started playing a few years ago and bought a DSL40CR and absolutely love it... Loved it, because it died. I turned it on one afternoon, strummed a few chords and the volume slowly reduced to zero, no popping, no noises, just sounded like you were rolling the volume off until there was nothing on all channels. I did the obvious and unplugged the FX loop and my pedalboard then plugged straight into the front and nothing. I've pulled the chassis, checked the fuses, changed power tubes and still nothing. Unfortunately finding a useful manual has been a choir as I've yet to find one. Any suggestions other than take it to a tech?

A little background, I'm an industrial tech, familiar with electronics, soldering, troubleshooting... Not getting shocked lol. Just wanting to learn enough to rule out the common problems before sending it out for repairs.

 

[PelliX]

new MF'er!

Sorry to hear about the DSL. Do the valves still light up and/or get hot? If you're comfortable with electronics, you could carefully check the voltages on the secondary side of the transformer. Also, let's not rule out the simple; tried a cab? Checked the cable to the speaker inside the combo?

 

[fitz]

I've pulled the chassis, checked the fuses, changed power tubes and still nothing

Just power tubes?
Check Bias?
Did you try changing any pre-amp tubes?

then plugged straight into the front and nothing.

Did you try plugging straight into the loop return?

 

[ThreeChordWonder]

I don't know the DSL but my O50 had a mains fuse "hidden" in the mains input socket. Might be worth checking if you haven't.

 

[JohnH]

A slow volume fade-out would be consistent with a loss of heater supply, maybe to part of the amp, or to all if it, ie, it could be just to the power tubes (no sound at all), or just the preamp valves (guessing you might still get a slight hiss from the power stage).

So, see if any tubes are still glowing.

 

[matttornado]

I had the standby switch go bad on mine. Maybe check to see if it works with your meter just to rule that out? It has push on connections so it should be easy to check.
I found a 3 pack for 12 bucks on Amazon. Easy fix but the switch was a pain in the butt to get out.

 

[Pete Farrington]

see if any tubes are still glowing

Yes, great point, slow clean fade out (not fizzly) can indicate heater power has been lost somewhere, somehow.
There's not a standard level of glow from valves, some may glow a lot, others very little. So if any don't seem to be glowing hardly or at all, a quick gentle touch of the glass envelope is the surest test.
Be careful, the output valve envelopes, EL34 here I think, will run much hotter than on the much smaller ECC83s.

DSL40CR is the new version with EL34 and no schematic in the public domain yet, right?

 

[jeffb]

There are some preamp tubes that don't really light up much- several varieties of New Sensors e.g. . I wouldn't base anything on a visual there (except for if it's white/lost vacuum).

Change with KNOWN good preamp tubes.