Yamaha C4 repair advice needed re: MM phono section

[texanater]

Hey All,

I just got a yamaha C4 and absolutely love it. The MM phono section isn't functioning. There's no bottom end, the volume is very low and its sounds muffled. There are three phono inputs (2 MM and 1 MC) and I think its the selector switch that selects which phono input, not the switch that chooses between aux, tape, tuner and phono. I've hit it pretty hard with radio shack contact cleaner and that brought back the right channel but the left channel is still all but dead.

Is there any benefit in getting the name brand deoxit rather than just the radio shack contact cleaner?

Further, is there anyone in the Los Angeles region that is highly recommended for this kind of repair?

Also, are there any recommendations for parts replacement such as bulbs and on/off switches?

Lastly, I also have a yamaha M4. I'm a bit new to the vintage gear hobby, I understand that the caps usually go bad after a couple decades. When do you know you need to replace them. It sounds fine now so should I follow "if it aint broke" or should the amp be serviced for good measure?

Lastly lastly, my dad came out for Christmas and liked the C4/M4 combo so much he bought a pair for himself. Anythoughts about a Houston area tech who could service his as needed?

Thanks so much for your thoughts!!!

Nate

 

[avionic]

Deox-it is by far 200% better product than the radioshak brand contact cleaner.The phono will be at a lower output than a tape deck or CD player we are talking microvolts versus volts. The C-4/M-4 combo is excellent . Most of your C-4 issues can be cleaned up with a proper treatment of Deox-it.. As for caps in the M-4 as well as C-4 there are no doubt some that are probably in need of replacement ..that gear is going on 30 years old.

 

[texanater]

aim high

active duty USAF here as well as prior Army. Thanks for your thoughts. The dogma of "if it aint broke" has served me well. What can I expect from the cap replacement and is it user level? I'm fairly handy with a soldering iron, but never attempted this particular maneuver. What caps in particular would you replace and is this an opportunity for upgrade? If so do you have suggestions? Sorry for the newbie questions as I am pretty new to this vintage stuff but I'm really enjoying it so far.

Nate

 

[avionic]

Generally I look the unit over and look for signs of leakage or excessive heating of the caps.Caps generally run cool to the touch..If it is hot theres a problem.If the plastic label sleeve has shrunk down on the cap its gotten to hot.If the cap has a noticeable bulge it is probably toast.Capacitors are cheap ..The Panasonic line FC series are a excellent replacement choice.

 

[avionic]

http://www.audiokarma.org/forums/showpost.php?p=1273240&postcount=3
Maybe of some use for the M-4...Your Welcome..

 

[texanater]

Fyi

I hit the C4 with deoxit and its back to life and sounds great. Good stuff!!!! I plugged in my Linn Majik just for shiggles and the yamaha blew it out of the water.

 

[avionic]

Awesome...C-4 is my favorite pre-amp...:thmbsp:

 

[brutal]

"If it ain't broke..."

true, but some preventive measures can alleviate additional parts breakage and for those unobtainium items, the end of life for the piece.

I've been finding a lot of 30 year old Yami with corrosive glue eating up components and always inspect for that. It's not MY climate either, these come form all over and I live at about 13% avg humidity...

BTW, C-4 is an AWESOME pre.