Hi…I was playing jamming and suddenly I lost all audio coming through my power station. When I disengage I have full volume. Help!
check the mains fuse. if it’s blown replace it. if it blows again it could be bad power tubes or some other fault.
Hi there. The fuse looks good.
if you haven’t already then also check the HT fuse which is on the inside of the amp: https://youtu.be/5Bq1SiU1w6A?si=KG7OlM0CZGoTO4Vq&t=240
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Okay yes the internal fuse is blown. I can replace that but will it blow again? It seems unlikely the power tube would be failing so soon?
Okay I tried replacing the blown interior fuse but I’m still not getting audio when the unit is engaged.
The fuse may have blown again. A fuse is intended to protect internal circuitry. When it blows, it’s telling you it’s trying to do its job.
The internal fuse will usually blow because of a bad power tube. In some cases it may blow because the internal line spike suppressor capacitor took a hit from an AC line surge or spike. The suppressor is the small blue disc capacitor next to the internal fuse clip. Sometimes after a line voltage surge, this cap will pop apart and you’ll be able to see that it is split open.
To find out which is the case, first remove the power tubes and then replace the fuse again. Now power it up once and turn it off. You can do this with the cover off and looking at the fuse. If it’s the suppressor, the fuse will flash with no power tubes installed. If the fuse remained intact, you have a bad power tube.
If its the suppressor, we need to determine whether you want to proceed further or have it serviced professionally. This would be a simple matter of removing and replacing the suppressor.
Dave
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Okay so I removed the power tubes and when turning on the unit, the power tube remains intact. So it’s one of the power tubes?
Could you please clarify your newest post?
Thanks.
Yes sorry I meant the fuse stays intact when I turn the unit on with the power tubes removed.
Yes, that means one of the power tubes is bad.
You can get those from Fryette or order directly here:
Okay thank you. Can I just buy these and plug them in? Or is there servicing that needs to be done?
Just plug them in and let them warm up a bit.
Hi there. So I’ve replaced both power tubes and I still have no sound when the unit is engaged.
Did you check to make sure the internal fuse is good after installing the new tubes?
I can double check tonight but I checked it yesterday and both fuses were still intact.
If you are checking visually, and it doesn’t look obviously blown, it could still be open from a previous attempt.
Hi there. Okay so I just replaced both fuses even though they were both still intact and I’m still having the same issue. The new tubes are both glowing so they are working as far as I can tell. And audio still works when the unit is bypassed. Just not when engaged. Is it possible a component is fried?
It might be a bad preamp tube. Do you have a spare 12AX7 laying around, or an amp you can steal one from? I would try that.
Also, do you have anything in the loop?
If so, disconnect that temporarily.
If not, put a jumper cable from the Send to the Return and let me know what happens.
Dave
Hi…yah I did have some pedals in the FX loop but I’ve removed them. I can try the jumper and I’ll try the preamp tube tonight. Thank you.