Members zeusecho Posted January 30, 2011 Author Members Share Posted January 30, 2011 I had a similar problem with my 4th world country manufactured 5150 clone. It's a Bugera, so I assumed what any reasonable person would assume; the Bugera had finally failed me. I checked tubes, fuses, etc when in the end it was the jackplate on my Marshall 4x12 cab. The mono/stereo switch had gone out. Thanks I know the cab is good as I just wired it myself last month, and it's mono so there's no switch to fail. One of the output jacks on the 5153 though was loose when I bought it (used) which I fixed straight away but maybe someone tried to use the bad jack before I got it and stressed/damaged the OT? Link to comment Share on other sites More sharing options...
Members zeusecho Posted January 30, 2011 Author Members Share Posted January 30, 2011 Check the B+ and heater voltages on the power tubes if you know how to do it without zapping yourself. B+ = 0VAC and 130VDCHeaters = 2.5VAC and 0VDC Link to comment Share on other sites More sharing options...
Members BC Audio Posted January 30, 2011 Members Share Posted January 30, 2011 Thanks dude. I tested all the fuses I can see, like five of them and all good. It is possible for a fuse to test ok, but at working voltage and current it is open (failed). Link to comment Share on other sites More sharing options...
Members Sun Destroyer Posted January 30, 2011 Members Share Posted January 30, 2011 It is possible for a fuse to test ok, but at working voltage and current it is open (failed). ^This. And I'm gonna bet you a new set of tubes will fire that bad dog right back up. Link to comment Share on other sites More sharing options...
Members zeusecho Posted January 30, 2011 Author Members Share Posted January 30, 2011 It is possible for a fuse to test ok, but at working voltage and current it is open (failed). Really I've never seen that? I guess it can't hurt to change them. I suspect the OT though because of the issue with the output jack (although I have played the amp for a few months after is was fixed). Is that unreasonable given the voltage measurements above. Link to comment Share on other sites More sharing options...
Members zeusecho Posted January 30, 2011 Author Members Share Posted January 30, 2011 ^This. And I'm gonna bet you a new set of tubes will fire that bad dog right back up. Hopefully it will. I'm gonna place an order with Laura today. Link to comment Share on other sites More sharing options...
Members Sun Destroyer Posted January 30, 2011 Members Share Posted January 30, 2011 Perfect. Get those Sovtek WXT+'s she recommended too. They are cheap and sound killer in that amp. Link to comment Share on other sites More sharing options...
Members Zozobra Posted January 30, 2011 Members Share Posted January 30, 2011 B+ = 0VAC and 130VDCHeaters = 2.5VAC and 0VDC Okay, that B+ seems awfully low. I'd guess it'd be about 450VDC?Can you do the measurement with the tubes pulled? Also if you can take a reading straight off the rectifier and then after the reservoir cap? Link to comment Share on other sites More sharing options...
Members zeusecho Posted January 30, 2011 Author Members Share Posted January 30, 2011 Thanks for your help EVERYONE! It is fixed!!! It turned out to be a fuse but not really a fuse at the same time. It was the connection to the fuse. The connector looks like it has some corrosion and was a little loose. I cleaned it up with a wire brush and pinched the sockets together to add some pressure on the fuse and it's good as new. I'm surprised that just taking out the fuse and reinstalling it the several times that I did did not fix the issue initially. Peace out...I'm going to play nao! Link to comment Share on other sites More sharing options...
Members zeusecho Posted January 30, 2011 Author Members Share Posted January 30, 2011 Perfect. Get those Sovtek WXT+'s she recommended too. They are cheap and sound killer in that amp. Even though it's fixed, I still may try some other tubes though as I'm not a big fan of JJs. Link to comment Share on other sites More sharing options...
Members Sun Destroyer Posted January 30, 2011 Members Share Posted January 30, 2011 Even though it's fixed, I still may try some other tubes though as I'm not a big fan of JJs. Glad you got your amp working! I agree, I'm not a big fan of JJ 6L6's either. Ruby and Sovtek's do just fine for me. I'm a cheapskate though so take that with a grain of salt. Link to comment Share on other sites More sharing options...
Members MOOMOO Posted January 30, 2011 Members Share Posted January 30, 2011 Are the tubes glowing? If not, I suspect one of the powertubes failed and took out an internal fuse. That would be the first thing to check, at least. One of my tubes does not fire up also, I hope that is all it is, the amp still comes on and plays but I stopped using it when I realized the tube not firing. Hope Phatgirl can get me together this week. Be even better if it's just a bad tube... Link to comment Share on other sites More sharing options...
Members charveldan Posted January 30, 2011 Members Share Posted January 30, 2011 http://www.rig-talk.com/forum/viewtopic.php?f=3&t=87046 Here's one of Eddie's personal amps complete with Sovtex WXT's. Link to comment Share on other sites More sharing options...
Members zeusecho Posted January 31, 2011 Author Members Share Posted January 31, 2011 http://www.rig-talk.com/forum/viewtopic.php?f=3&t=87046 Here's one of Eddie's personal amps complete with Sovtex WXT's. Oh nice, that's a pretty convincing argument to try those tubes. Link to comment Share on other sites More sharing options...
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