My beloved 2270 has a slight poping/static sound out of one channel. Not very noticable and very intermittent but it is there. Going to drag it out of its wood case and do the deoxit on the volume pot and other ones Any ideas if something else may be failing?

What sucks is going through all that and not being sure if it is really fixed or not.

The input differential pair transistors in the power amplifier seem to be troublesome in this generation of Marantz gear. Match a new set and replace them.

Thanks for the reply, Echowars.

I have never tried this before. I had one side replaced, so I am assuming that the Motorola ones are the originals. SJ2517 & 18 would need to be ordered. Looks like they just screw in. Would anything else need to be done besides bias and DC offset adjust?

Wrong end of the amp. The differential pair transistors are the small ones at the input, not the large ones at the output. ;)

Ah, I slooowly learning new things around my machine. They all look original to me. If I do this on my own, I'd replace them all. Same question though, do they just screw in, and adjust bias, DC offset?

On that note. What is the correct way to remove the amp board from the power transistor heat sink.

Ah, I slooowly learning new things around my machine. They all look original to me. If I do this on my own, I'd replace them all. Same question though, do they just screw in, and adjust bias, DC offset?:no:

Wrong end of the amp. The differential pair transistors are the small ones at the input, not the large ones at the output.
Read and heed..:D

Learned a little here, at least I knew what the transisitors were. Just picked the wrong ones. Not so bad for one who knew absolutley nothing about stereos, except how to listen, not so long ago.....

And I havent' had one electrocute me yet....

So far the problem seems to be the 2 L R mono buttons. Wiggling them seemed make them act the way they did from time to time. Odd, since I never use those controls. Bit of cleaning seems to have cured the problem... for now.

I"m sure Echowars is right if the problem persists. At least I'll have an idea whats up.

Switches should probably all be thoroughly cleaned with DeOxit before you really consider any radical electrical fixes.

Switches should probably all be thoroughly cleaned with DeOxit before you really consider any radical electrical fixes.




This is so true. I fixed my friends stereo that had a channel slipping in and out. Took the face and bottom off, Deoxit, followed by Faderlube. Still works great. He thinks I know a lot about stereos. I addmitted I really don't know jack.