HD147: Problem with sudden volume changes

[BM_Fan]

Hey everyone,

 

I am hailing from northern germany (near Hamburg or Kiel). Recently I bought a HD147 second hand after I looked for a modelling solid state amp with many possibilities of sound.

 

Unfortunately, after a few hours of playing it turned out that there is the following problem:

 

While playing the volume changes suddenly. It seems to be related with changing channels (meaning the four channels A, B, C and D). F. e. when I turn the amp on and just start playing with the last used channel I can play for quite a while. But when I change channels (f. e. from B to A), after a short time the volume decreases significantly and stays like that. To get back to the old volume level another channel change helps for a few seconds or a minute (f. e. going back to B and again back to A) but the volume drop happens over and over again.

 

What I already tried:

- different cab, different speaker and instrument cables

- not using effects loop (normally I love to use a looper pedal in it), turning effects loop off via FBV Shortboard MKII

- not using FBV Shortboard MKII

- Guitar works well with other amps

- different location (f. e. concerning electricity supply)

 

So I think it is really a technical problem of the amp. I also read some hints concerning volume issues with HD147, like the following:

- volume and other potis could move at higher volumes: on my HD147 they don't move so easily, the problem also appears at lower volumes. Also I turned all potis except master volume to max.

- I read a post where someone described corrosion and similiar in the electrics of many HD147. I opened it today (I have close to no clue about electricity, technics and stuff) but all connections, cables and platines which I could see looked good to me.

- overheating: in my band rehearsal room I also had a complete volume fade for a few seconds, volume coming back by its own. I don't knwo if it's the same problem or someting else. Of course the volume was much louder and the amp pretty warm (not hot). But the main problem appears also at home when the amp is cold.

 

My last idea would be to look for a skilled local technician who can help me but that wouldn't be that easy to find... do you have any ohter idea?

 

I would appreciate any ideas and help. If you got some technical advice, please write it for idiots so I can comprehend.

 

Thanks in advance.

[psarkissian]

Take it to the nearest authorized Line 6 service center in your area.

Looks like the closest one to Hamburg is PMS Electronics in Minden.

 

https://line6.com/find/service_center/

 

They should check it out. They have experience with our product.