Mark V Problem

[EdwardC]

Hello,

So my Mark V was turned off for about three weeks. I turned it on today to practice and everything was fine, went out of the room came back and the lights were off on the foot switch and front panel of the amp. I tried to turn it back on but the lights will not turn on neither on the foot switch or front panel. So I verified the outlets and my Furman and everything is good on the power outlet and the Furman. I checked the fuse and it looks fine. The tubes look like they turn on but they seem to not be getting full power. The fan on the back I also can not hear it turning on. Has this happened to anyone here? The amp is close to 1.5 years old.

 

[jaslan]

http://forum.grailtone.com/viewtopic.php?f=33&t=70633&start=15#p486618
Check out this thread. It sounds like the same problem. If it is, it will, unfortunately, have to go to a repairman.

 

[Nicklotsaguitars]

I put my amp away away over the Christmas period. And experienced similar when I did switch it on again. Just momentarily flicked off then back on again.
Hasn't done it since, had about 14 hours use since

 

[EdwardC]

Just to update the situation. I talked to the guys at Mesa Boogie, obviously excellent customer service, and they seemed to already know that the amp needs a diode update. I will have to send the amp to them for the repair given there's no certified technician close to my location. It is under warranty. So for any of you guys that may experience this in the future, know that you will most likely need to replace the diodes. When I am done with the whole thing I'll try to post it here so you guys can have a time frame. I bought the amp July 15 2015 and it had not shown any symptoms.

Thanks for your help.

 

[Nicklotsaguitars]

Worrying. I bought my amp April 2015. It was made August 2014.

 

[domct203]

Worrying. I bought my amp April 2015. It was made August 2014.

Call Mesa and give them the serial number, they can let you know if the amp is suspect so you can get this fixed before it lets you down at a gig.

Dom

 

[Nicklotsaguitars]

Good advice Dom. Thank you.
Though a call from here will likely get on for the same cost as a new set of valves. Think I'll email em.
Thanks again mate

 

[jaslan]

Mine has been rock solid so far since the diodes were replaced.

 

[TomGuitar]

Hello,

So my Mark V was turned off for about three weeks. I turned it on today to practice and everything was fine, went out of the room came back and the lights were off on the foot switch and front panel of the amp. I tried to turn it back on but the lights will not turn on neither on the foot switch or front panel. So I verified the outlets and my Furman and everything is good on the power outlet and the Furman. I checked the fuse and it looks fine. The tubes look like they turn on but they seem to not be getting full power. The fan on the back I also can not hear it turning on. Has this happened to anyone here? The amp is close to 1.5 years old.

I have repaired on mkV with that symptom. It turned out to be one rectifier diode 1n4007 in the 12v voltage department that had broke down. No 12v voltage, no relay active, no life in the amp. Easy fixed though.

 

[IronSean]

I also have a diode in the Rectifier circuit go down and need replacing under Warranty.