Members Tommy Horrible Posted July 8, 2011 Members Share Posted July 8, 2011 So my Mark IVB short head just stopped making sound. I have no idea what is wrong with it. I replaced every tube with brand new mesa tubes and the problem still persists? Any ideas? The damn thing has 1000 knobs and switches and I'm not sure what could be wrong? Link to comment Share on other sites More sharing options...
Members sleewell Posted July 8, 2011 Members Share Posted July 8, 2011 mr. horrible, sir, is it plugged in? Link to comment Share on other sites More sharing options...
Members Tommy Horrible Posted July 8, 2011 Author Members Share Posted July 8, 2011 mr. horrible, sir, is it plugged in? Yes, LOL Link to comment Share on other sites More sharing options...
Members Sixtonoize Posted July 8, 2011 Members Share Posted July 8, 2011 Recording (silent) mode enabled? Push the Master Volume knob back in. Link to comment Share on other sites More sharing options...
Members Rampage Posted July 8, 2011 Members Share Posted July 8, 2011 1. Does the fuse still test good on a multimeter?2. Are you sure that the amp is plugged into the cabinet properly and the guitar into the amp properly? Cables working properly?3. Do you have the silent recording pulled (Output Level control)? Link to comment Share on other sites More sharing options...
Members ~Abstract~ Posted July 8, 2011 Members Share Posted July 8, 2011 Yes, LOL Ok...I'm going to have you turn it off, then wait a little bit and turn it back on. Let me know when you have completed this. Link to comment Share on other sites More sharing options...
Members Tommy Horrible Posted July 8, 2011 Author Members Share Posted July 8, 2011 Ok...I'm going to have you turn it off, then wait a little bit and turn it back on. Let me know when you have completed this. 1. Yes, the fuse seems fine. But I don't know how to test it with a multi meter. 2. Yes, it's plugged into the cab properly, there is actually some sound comming out, but just the back ground hiss of the amp running if I crank everything to 10. 3. Nope silent recording isn't pulled out, but doing that makes the background hiss of the amp running go away with everything cranked. Tell me if you guys see anything wierd in this picture. Link to comment Share on other sites More sharing options...
Members primeholy Posted July 8, 2011 Members Share Posted July 8, 2011 Was it doing the exact same before you changed out tubes? Link to comment Share on other sites More sharing options...
Members ~Abstract~ Posted July 8, 2011 Members Share Posted July 8, 2011 Change speaker and instrument cables...for like items, don't swap. Link to comment Share on other sites More sharing options...
Members Rampage Posted July 8, 2011 Members Share Posted July 8, 2011 I assume it does the same thing on each of the three channels? Have you tried plugging your guitar straight into the effects return to see if it produces sound? Have you cleaned the effects loop jacks? I haven't had an issue on any of my MKIVs with the loop, but one of my 5150s needed the loop cleaned. Link to comment Share on other sites More sharing options...
Members Tommy Horrible Posted July 8, 2011 Author Members Share Posted July 8, 2011 Also, when I was just messing around with I for a very brief second was getting some very low level guitar signal comming through the lead chanel that was barely there and sounded clean with the amp cranked way up. Then when I unplugged from my tuner and plugged directly into the amp to make sure nothing else was going wrong with the signal chain the signal was gone. Also, I have my TSL plugged in right next to the Mark IV into a seperate cab and the guitar and chord work perfectly with that amp. Link to comment Share on other sites More sharing options...
Members Tommy Horrible Posted July 8, 2011 Author Members Share Posted July 8, 2011 Was it doing the exact same before you changed out tubes? Yes. That's why I figured it was a tube problem and bought all brand new mesa tubes. It turns out, it wasn't. Link to comment Share on other sites More sharing options...
Members guitarbilly74 Posted July 8, 2011 Members Share Posted July 8, 2011 what about the speaker cable? Link to comment Share on other sites More sharing options...
Members Tommy Horrible Posted July 8, 2011 Author Members Share Posted July 8, 2011 I assume it does the same thing on each of the three channels? Have you tried plugging your guitar straight into the effects return to see if it produces sound? Have you cleaned the effects loop jacks? I haven't had an issue on any of my MKIVs with the loop, but one of my 5150s needed the loop cleaned. Yup, same thing with all 3 channels. I'll check plugging it into the effects return BRB. Link to comment Share on other sites More sharing options...
Members Rampage Posted July 8, 2011 Members Share Posted July 8, 2011 I can't quite tell from the picture (crappy monitor, equally crappy eyes), but is the amp set on External Switching? I accidentally put mine on External Switching (instead of Footswitch) once and all I got was a very quiet clean tone on each and every channel, no matter the volume settings. Link to comment Share on other sites More sharing options...
Members primeholy Posted July 8, 2011 Members Share Posted July 8, 2011 I can't quite tell from the picture (crappy monitor, equally crappy eyes), but is the amp set on External Switching? I accidentally put mine on External Switching (instead of Footswitch) once and all I got was a very quiet clean tone on each and every channel, no matter the volume settings. There you go! I think I had that happen before. Link to comment Share on other sites More sharing options...
Members Rampage Posted July 8, 2011 Members Share Posted July 8, 2011 There you go! I think I had that happen before. It happened right after I brought it home from the shop for a repair. One of those, "aw man, what now" feelings. I was pleasantly surprised by my stupidity that day. Link to comment Share on other sites More sharing options...
Members Tommy Horrible Posted July 8, 2011 Author Members Share Posted July 8, 2011 I assume it does the same thing on each of the three channels? Have you tried plugging your guitar straight into the effects return to see if it produces sound? Have you cleaned the effects loop jacks? I haven't had an issue on any of my MKIVs with the loop, but one of my 5150s needed the loop cleaned. Ok, plugged into the effects return and I got sound out of it, on all three channels, wierd, but the tone didn't sound right, it was really clean on all three channels. Link to comment Share on other sites More sharing options...
Members Rampage Posted July 8, 2011 Members Share Posted July 8, 2011 Ok, plugged into the effects return and I got sound out of it, on all three channels, wierd, but the tone didn't sound right, it was really clean on all three channels. Yeah, it should be very clean. I should have mentioned that. When you plug into the return, you are bypassing the preamp and going straight to the power amp. What that tells me is that your power section is fine, so your problem is somewhere in the preamp. The last thing I would try is unplugging the reverb tank RCA cable that connects it to the chassis, turning the reverb control to zero, turning the recording out control to zero, turning the slave out control to zero and trying the amp without EQ. Just try to narrow everything down. You may even want to try it running a cable between the effects loop output and input to see if that does anything. Link to comment Share on other sites More sharing options...
Members Tommy Horrible Posted July 8, 2011 Author Members Share Posted July 8, 2011 I can't quite tell from the picture (crappy monitor, equally crappy eyes), but is the amp set on External Switching? I accidentally put mine on External Switching (instead of Footswitch) once and all I got was a very quiet clean tone on each and every channel, no matter the volume settings. Nope, it was set to lead in that picture, just make sure I put every knob on the front of the amp to 10 and rolled around from R1-->R2----> lead, still no sound but background hiss, unless I plug into the effects return. Link to comment Share on other sites More sharing options...
Members Tommy Horrible Posted July 8, 2011 Author Members Share Posted July 8, 2011 Yeah, it should be very clean. I should have mentioned that. When you plug into the return, you are bypassing the preamp and going straight to the power amp. What that tells me is that your power section is fine, so your problem is somewhere in the preamp.The last thing I would try is unplugging the reverb tank RCA cable that connects it to the chassis, turning the reverb control to zero, turning the recording out control to zero, turning the slave out control to zero and trying the amp without EQ. Just try to narrow everything down. You may even want to try it running a cable between the effects loop output and input to see if that does anything. Ok, did all this, still nothing when I plug into the input on the front, all though it did get slightly louder when I had my guitar plugged into the effects return and the effects send plugged into the front instruement jack. Link to comment Share on other sites More sharing options...
Members primeholy Posted July 9, 2011 Members Share Posted July 9, 2011 Ok, did all this, still nothing when I plug into the input on the front, all though it did get slightly louder when I had my guitar plugged into the effects return and the effects send plugged into the front instruement jack. What he meant there was to run a patch cable from the effects send, to the return, and plug your guitar to the normal input of the amp on front. Link to comment Share on other sites More sharing options...
Members Holy-diver Posted July 9, 2011 Members Share Posted July 9, 2011 Call mesa tomorrow. Link to comment Share on other sites More sharing options...
Members Tommy Horrible Posted July 9, 2011 Author Members Share Posted July 9, 2011 What he meant there was to run a patch cable from the effects send, to the return, and plug your guitar to the normal input of the amp on front. Oh, no sound when I do that. Link to comment Share on other sites More sharing options...
Members charveldan Posted July 9, 2011 Members Share Posted July 9, 2011 Oh, no sound when I do that.Wondering if the amp has internal fuses? I assume you checked all the other fuses by replacing them? Link to comment Share on other sites More sharing options...
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