tallman5353
New Member
Hi there,
Recently picked up a nice matching akai system from a garage sale, the amp being the AM-M939
Unfortunately upon firing it up the right channel appeared to be barely working, crackling some music at times.
I took the cover off and did some diagnostic, no outstanding dry joints, all caps and transistors don't appear burnt out. I've cleaned all of the pots and switches for balance, volume, tone etc with deoxit.
I did swap the output transistors from each channel to the other, the problem persists still on the R.
I also tested the idle current, the left channel measures correct at 20mv, however the right is a flat 0v. Adjusting the VR pot does nothing.
Anyone have advice? I had a peek at the service manual schematic, but it is a bit of a maze to me.
Thanks in advance.
Recently picked up a nice matching akai system from a garage sale, the amp being the AM-M939
Unfortunately upon firing it up the right channel appeared to be barely working, crackling some music at times.
I took the cover off and did some diagnostic, no outstanding dry joints, all caps and transistors don't appear burnt out. I've cleaned all of the pots and switches for balance, volume, tone etc with deoxit.
I did swap the output transistors from each channel to the other, the problem persists still on the R.
I also tested the idle current, the left channel measures correct at 20mv, however the right is a flat 0v. Adjusting the VR pot does nothing.
Anyone have advice? I had a peek at the service manual schematic, but it is a bit of a maze to me.
Thanks in advance.