Yamaha M-2 speaker relays

[jhal]

My M-2's speaker relays are both in need of replacement. I have been using the "B" output, but it is acting up as well now. Both channels can cut out or sound "muddy" at times. Pushing the speaker switch several times usually fixed it until the next power up, until recently. I hope it's only the relay(s). Of course, I will check for cold solder joints while I am in there.

Don't worry, I know what I am doing. :headscrat

I want to order new ones. Can anyone that has experience repairing this amp please tell me the part number from Mouser, Digikey, or any of the other big electronics parts suppliers? :scratch2:

Pretty please!

Thanks, John.

 

[brutal]

I'll be watching the thread with you.

I Can't help you on the relays just yet, but I may soon be undertaking them in my quest to finalize the repairs on my busted (bought busted) M-2. The dead R channel has been fixed with temp parts but the Left spk-a output is still silent. The new parts just came in today from Mouser, but I won't get to it until this weekend, and even then around the Sat aft work schedule.

Once I get the R channel completed, I'll probably have to tear into the speaker relay board.

Sorry to be of little help at the moment, but if you don't get an answer and want to wait until I tear into mine to determine the possibility of getting the proper relay, I might be able to help out later.

 

[jhal]

Thanks, in the meantime I will look at the service manual to see if it is any help. I just hate to tear into the amp and have it sit for a week (with no main system) while I wait for parts.

A tempermental amp is better then no amp.

 

[brutal]

I installed most of the new parts tonight and she's still singing like the fat lady. If I can get motivated tomorrow morning, I may tear into the speaker relays. The A side relay def doesn't sound as strong as the B side. Looks like the rear panel has to come off and a little desoldering is needed. No matter, now that I've got it working, I'll be tearing out the crap binding posts someone installed on one side and replacing them all with something worthy.

The SM only lists to the relay board

Stay tuned.

 

[jhal]

I found the number for the relays in the service manual, in the last page of the parts list.

Relays "RY601" and "RY602".

Part # MSJ12 D2-0

I will see if I can find a suitable match. Maybe Yamaha still stocks it?

 

[avionic]

"RY601" and "RY602".

Is the schematic designation ie, Relay 601 and 602. The actual part # should be printed on the relays plastic case. I'm guessing, but probably something like " HL2-P-DC12V ". You will have to verify your particular application.

 

[jhal]

Yes, ry601 and ry602 denotes the schematic location. The number MSJ12 D2-0 is what is on the parts list for those two relays.

 

[brutal]

http://www.audiokarma.org/forums/showpost.php?p=3057083&postcount=16

Yamaha M-2 speaker relay (for the search bots)

Marked:

TYPE MSJU
12VDC

DEC
142 JAPAN

 

[jhal]

Thank you! I just saw the latest updates to that thread as well.

 

[Phaseone]

You can also try a points file, used when cars had points, and a bit of copper antiseize, used for high heat bolt applications. Just like cleaning switches with Deoxit. More than likely, the contacts are coated, so don't file them too much. Or 400 to 600 emery cloth will do.

 

[JBL GUY]

There are actually tools made specifically for this task...

The GC 0.120" Wide Fineline burnishing tool consist of stainless steel strips, micro-scored to an ultra-fine surface. They remove oxide and corrosion on relay and switch contact points made of platinum, paladium, molydenum, gold tungsten and silver. The fineline tool is recommended for use on small and miniature components.

I used tools like these in the "Old" days when I used to work on mechanical pinball machines. Just a big wooden box full of relays...

And even using a strip of heavy weight printer paper soaked with DeOxide will do a good job.

It can take some work...But for relays that are hard to source.

 

[avionic]

http://www.sears.com/shc/s/p_10153_12605_00994107000P?keyword=ignition+file
Probably just a temporary fix depending on the condition of the contacts.Especially if they are burnt or badly pitted.

 

[JBL GUY]

http://www.sears.com/shc/s/p_10153_12605_00994107000P?keyword=ignition+file
Probably just a temporary fix depending on the condition of the cotacts.Especially if they are burnt or badly pitted.

Yep with out a doubt if they are in bad shape.

The point I was making is that in the end you want to end up with a smoothly polished contact surface...Burnish away the pits and burns if possible then use the paper and DeOxite to remove and material left on the contact surface.

If I had a dollar for every set of relay contacts that I saved I would not have to worry about the price of vintage audio gear.