Marantz 2275

[Stan Ski]

First post here on this forum. My main hobby is antique tube radios. Was wodering if anyone can help me. Have a Marantz 2275 that i am trying to repair for my son in law. The problem is the left or some times the right channel will disappear. To only way i can get the channel to come back is to turn the volume control way up. This will work sometimes all day but not always. I installed a new set of dial lights and since i had it apart i cleaned all the pots. Also cleaned the relay contacts with very fine sandpaper. After i did this everything was fine but know it is doing the same thing that he was complaining about. Is there any common thing on these stereos that would cause this? Thanks for any help
Stan Ski

 

[onepixel]

Hey Stan,

My 2275 was doing the same thing. Mine was an easy fix. The pre-out and pre-ins were the culprit. Cleaning them and all the pots with DeoxIT fixed it.

Good luck and welcome to AK.

Carl

 

[mea2112]

You may need to clean all the pots a second or third time if they're really dirty or oxidized.

 

[sssmokin99]

As mentioned, the pre-in/out area should be checked, the pot cleaned again, and also check the speaker relay. If it needs to be replaced, see my post relating to a 2250b for the part number- it is the same for both models...

 

[Redboy]

Second the speaker relay notion. They're glitchy little critters sometimes. You could try cleaning the contacts - do some searches for that before you dive in - to see if that helps. Sometimes it'll do the job, but sometimes your best bet is to just replace the durn thing.

 

[hdewees]

There is a service bulletin from Marantz dated 5-14-76 to replace the protection relay. Service bulletin M-2275-4 :

If Speaker Protection Relay (L801) malfunctions it is recommended that L801 be replaced with an improved twin contact relay part numer LY2-0240-090. This improved relay has been incorporated into units with serial number 10951 (USA) 60601 (Canada) , 52001 (Europe) and later.

I think it is an Omron relay but don't hold me to than.

 

[jblmar]

What hdewees said.
The relay was a common problem with the 2250, 2275... from 1975. The 'B' issues replaced the relay and power switch. Both were a real PITA. I remember bringing my 2250 back to Marantz (when they were in Woodside, NY) almost every 2 weeks for channel drop-out problems. Replacing the relay solved the problem.
Replace the relay. That should solve the problem with yours as well.

Ron

 

[Redboy]

Check out this thread for details on Omron relays:

http://audiokarma.org/forums/showthread.php?t=90275

I asked specifically about the relay for the 2275, but never got so far as to actually order one.

 

[Stan Ski]

Had the unit on my bench upside down. Had it playing and started probing around with a small wood dowel. Found that if i moved the wires that connect to the pre in/out terminals it would make the left or right speaker cut out. Cleaned this area. Tryed it again and could not get it to fault. Have had it playing all day now and it sounds great. So i beleive the problem is gone. Thanks for all the help. If you guys ever play with tube radios try the Antique Radio forum (ARF). Great bunch of people there to.
Stan Ski