Induktionator
Member
- Joined
- Jul 31, 2010
- Messages
- 14
- Reaction score
- 0
After a year of bliss, my Mark V had to go in the shop.
Recently it had been making an intermittent fairly loud 50Hz noise. Fine for hours then RRRR! RRRR! Any channel, any power setting, independent of any volume settings, regardless of if the efect loop or guitar cable plugged in or not. Swapped power tube pairs and inside each pair, no difference. Swapped all the preamp tubes one at a time, still happens. Switching channels sometimes made it stop for a little bit, I think because of the vibration of the relays clicking.
Then I opened it up to have a look if there's something obvious loose or burnt. And found the foil shield (Against radio interference) had shed a bunch of little aluminum boogies inside. One was sitting right on top of the connector for the cable between the main board and the power tubes board, a tiny melted spot underneath it. A couple more harmlessly sitting in the bottom of the chassis.
So if you open your Mark V, inspect the foil shield for any loose bits.
Great, I though, I found something clearly wrong. Played all day with it open, no sudden loud hum. Put it back together the next day, played a bit, then it does it again. I was so disappointed. I guess there's a couple more aluminum bits floating around in there that I didn't see, and moving the amp shifted them, or shifted the one that has been making the problem all along.
Unfortunately swapping the tubes around and opening it up cost me my warranty, but it's already been a year now. I think it's actually a bit of a design flaw, the chassis should ground against the shielding some other way that avoids damaging the foil. Right now I just want it fixed. Someone else can spend their time looking for what's wrong.
If you read on the internet you always read the bad news about a product. I would still recommend the Mark V, it's a great amp. I'm just a bit sad I'll be without it for several weeks. We'll see what the repair finds, maybe I'll give some feedback to Mesa.
Recently it had been making an intermittent fairly loud 50Hz noise. Fine for hours then RRRR! RRRR! Any channel, any power setting, independent of any volume settings, regardless of if the efect loop or guitar cable plugged in or not. Swapped power tube pairs and inside each pair, no difference. Swapped all the preamp tubes one at a time, still happens. Switching channels sometimes made it stop for a little bit, I think because of the vibration of the relays clicking.
Then I opened it up to have a look if there's something obvious loose or burnt. And found the foil shield (Against radio interference) had shed a bunch of little aluminum boogies inside. One was sitting right on top of the connector for the cable between the main board and the power tubes board, a tiny melted spot underneath it. A couple more harmlessly sitting in the bottom of the chassis.
So if you open your Mark V, inspect the foil shield for any loose bits.
Great, I though, I found something clearly wrong. Played all day with it open, no sudden loud hum. Put it back together the next day, played a bit, then it does it again. I was so disappointed. I guess there's a couple more aluminum bits floating around in there that I didn't see, and moving the amp shifted them, or shifted the one that has been making the problem all along.
Unfortunately swapping the tubes around and opening it up cost me my warranty, but it's already been a year now. I think it's actually a bit of a design flaw, the chassis should ground against the shielding some other way that avoids damaging the foil. Right now I just want it fixed. Someone else can spend their time looking for what's wrong.
If you read on the internet you always read the bad news about a product. I would still recommend the Mark V, it's a great amp. I'm just a bit sad I'll be without it for several weeks. We'll see what the repair finds, maybe I'll give some feedback to Mesa.