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Post by Mark and his Maz on Jul 13, 2014 6:12:10 GMT -7
Hi guys,
feeling a bit low here...switched the maz on today, flicked it off standby and then nothing...no sound at all. Hv taken everything out of the chain. Guitar straight into amp. The speaker is definitely working as I played my Orange head through it and it was fine.
hv recently chanced the preamp valves and the power valves.
don't hv a spare 5ar4 laying around but do you guys think it could be the rectifier valve? Looking at the valve itself it's glowing though...would have thought if this valve was going it would still make some sound?
would I be right in saying that if the amp lights up and the valves glow then it's not a fuse problem?
Would greatly appreciate any advice - not having a Z to play sucks!
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Post by headshrinker (Marc) on Jul 13, 2014 6:36:38 GMT -7
Could still be the rectifier even if it lights up. Fuses can look good even when they aren't. Best to meter them. If the phase inverter went you would also get nothing. I would start putting the old tubes back in working from the power tubes. Put the pair of them back in, see what happens. Then the phase inverter. Then I would go to V1 and work toward the phase inverter.
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Post by Jaguarguy (Mike) on Jul 13, 2014 6:46:13 GMT -7
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Post by Mark and his Maz on Jul 13, 2014 8:29:40 GMT -7
Right, will have to arm myself with a new 5ar4 and some new 750 ma fuses. The fuse in the amp appears to be ok though!
This is going to sound a super dumb question but I've never had to change a fuse in any of my amps before - are all fuses a standard dimension? The 750ma fuses I hv found on Amazon appear to be microwave fuses?
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Post by BritInvasion on Jul 13, 2014 8:46:46 GMT -7
Right, will have to arm myself with a new 5ar4 and some new 750 ma fuses. The fuse in the amp appears to be ok though! This is going to sound a super dumb question but I've never had to change a fuse in any of my amps before - are all fuses a standard dimension? The 750ma fuses I hv found on Amazon appear to be microwave fuses? 3AG Slo-Blo
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Post by Jaguarguy (Mike) on Jul 13, 2014 8:53:31 GMT -7
Right, will have to arm myself with a new 5ar4 and some new 750 ma fuses. The fuse in the amp appears to be ok though! This is going to sound a super dumb question but I've never had to change a fuse in any of my amps before - are all fuses a standard dimension? The 750ma fuses I hv found on Amazon appear to be microwave fuses? 3AG Slo-Blo Not sure if the same fuse is used overseas. Might want to check with John Preist at Peach Guitars for which fuse to use. Even if fuse looks ok they can be bad. Cheap to replace so I'd start with new fuse.
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Post by BritInvasion on Jul 13, 2014 8:58:33 GMT -7
Not sure if the same fuse is used overseas. Might want to check with John Preist at Peach Guitars for which fuse to use. Even if fuse looks ok they can be bad. Cheap to replace so I'd start with new fuse. Good catch , I didn't notice the OP's location when I responded. Could be a 5x20mm over there.
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Post by Eddie on Jul 13, 2014 10:58:02 GMT -7
Does the Non-reverb model have two fuses? My MAZ reverb does. What you are describing sounds like a fuse to me, as well. I have had to replace one or the other of mine a couple of times. The pilot light and tubes will still glow even if one of those fuses is blown, but you won't get any sound from the amp.
Hope a new fuse fixes you up. Good news is that if it is a fuse, fuses are cheap!
Let us know when you are back up and running, Eddie
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Post by Eddie on Jul 13, 2014 11:02:00 GMT -7
- just checked mine (again, I have a verb model) one fuse is a 2 amp and the other is a 1/2 amp
edit: checked the manual for the newer models and it looks like there is just one fuse holder on the back. Who knew? Anyway, that U.S. number is: Fuse Type: T 1.5 Amp 250v
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Post by Mark and his Maz on Jul 13, 2014 15:05:47 GMT -7
Good shout, prob best to check with the guys at Peach to be sure I get the right fuses.
Is there any reason a fuse might go? Is there any way to pre empt these things in the future?
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Post by zpilot on Jul 13, 2014 22:57:10 GMT -7
Usually a fuse will go when a tube shorts. That's a good thing because it protects the rest of the amp. Military grade tubes are more robust and less susceptible to shorting. American versions will have JAN in their labeling which stands for 'Joint Army Navy'. There are also Russian military surplus tubes available; mostly EL84 types. Your tube vendor will have information on these. Also, just be careful how you handle the amp while the tubes are still hot. That's when they are most easily damaged.
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Post by Jaguarguy (Mike) on Jul 14, 2014 5:52:05 GMT -7
I had one go the other day just after the amp came back from Doc's for a check-up. He said that sometimes there might be a small power surge that can blow the fuse. My amp was like yours - things lit up but no sound. i replaced both fuses (less than a buck a piece). Dropped them in - voila sound! Other biggest explanation of no sound is blown rectifier. So have a spare on hand just in case.
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Post by Mark and his Maz on Jul 15, 2014 7:36:44 GMT -7
Not only have Peach provided me the fuse info (1 amp slow blow) but they have sent me a couple as well
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Post by Jaguarguy (Mike) on Jul 15, 2014 7:39:41 GMT -7
John is a great guy servicing a great manufacturer making great products! How can you not love these guys???
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Post by Mark and his Maz on Jul 15, 2014 8:05:56 GMT -7
Yeah, Peach have fast become my favourite shop.
Regarding my Maz, I now just have to wait for my rectifier valve and hopefully my amp will then be back up and running!
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Post by Mark and his Maz on Jul 16, 2014 11:18:01 GMT -7
Mike, when you say your amp was like mine and everything lit up, do you mean the rectifier tube as well as the light on the front of the amp?
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Post by Jaguarguy (Mike) on Jul 16, 2014 14:11:12 GMT -7
Yes - everything appeared lit.
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Post by Mark and his Maz on Jul 16, 2014 14:37:02 GMT -7
Ok cool. Thanks for clarifying.
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Post by Mark and his Maz on Jul 23, 2014 12:30:52 GMT -7
So, I changed the rectifier valve and fuse....and still nothing. Then, I changed the PI valve and voila! My Maz is working again! Thanks for everyone's advice and patience. So happy to have my Maz back
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Post by benttop (Steve) on Jul 23, 2014 17:10:30 GMT -7
It is usually a tube - not always, but usually.
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