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doh! now what do I do about this relay?

targeteye

targeteye

Super Member
Check out the burnt,, rather melted relay contact arm! Good thing I opened it up to clean the contacts!

Anybody know of a source for a 24VDC protection relay? This is in my 300DC. Cant believe it would even play halfway decent.

Marantz part number is LY20240110, part number is MSJ24D2-0.

on the cover "TYPE MSJU 24VDC" DEC

Steve
 

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That device has seen better days! You might try Mouser Elect. You will need to know coil resistance,mounting style and pin configuration then compare what you have with what you need using data sheets .Unless someone else comes along with a usable replacement part number.:D
 
This is a very special speaker protection relay, as you can see on your picture, it has double contacts for each channel. The outer contacts are for strong current, while the smaller inner contacts are for the tiny currents, that's why they are gold-plated. The gold contacts close a little later to prevent arcing, which would destroy the gold plating very fast.
Your 300DC probably had a fatal breakdown of one amp-channel causing arcing on the relay contact.
I've been searching for those DEC-relays for years, could not find one.
But there are standard relays that will fit on the DEC footprint with minor modifications, here in Germany I can buy them from Finder Omron or Schrack.-

Helmut
 
You shouldn't have too much trouble finding a replacement.
Looks like a standard double poll relay.

@ruesselschorf

I do agree that there has been a problem with that channel.:thmbsp:
 
Last edited:
ruesselschorf said:
This is a very special speaker protection relay, as you can see on your picture, it has double contacts for each channel. The outer contacts are for strong current, while the smaller inner contacts are for the tiny currents, that's why they are gold-plated. The gold contacts close a little later to prevent arcing, which would destroy the gold plating very fast.
Your 300DC probably had a fatal breakdown of one amp-channel causing arcing on the relay contact.
I've been searching for those DEC-relays for years, could not find one.
But there are standard relays that will fit on the DEC footprint with minor modifications, here in Germany I can buy them from Finder Omron or Schrack.-

Helmut
Click to expand...

Heavy Sigh.......I have less troubles finding parts for 50 year old tube stuff. This solid state stuff is getting frustrating!

ruesselschorf,

I see what you are talking about on the smaller inner contacts and the gold plating. I have found a Omron relay that seems to be close. Its looks like I'll have to modifiy the board slightly (pin alignment). However this relay only has 10 amp contacts. This is a 150 watt per channel amp and 10 amps into 8 ohms is only 80 watts. I really need something with a 20 amp contact.

http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=Z977-ND

Any ideas? I someone can provide a part number I would be most appreciative.

Thanks
Steve
 
Musicalme said:
I do agree that there has been a problem with that channel.:thmbsp:
Click to expand...

Yes, one channel suffered a major meltdown. I've already found the correct original Toshiba output transistors to put back for the incorrect substitution someone made with that channel blew. I've also found what I think are good subs for the original driver transistors that went up in smoke also.

Now it looks like I'll need to hunt for a dang relay!

Steve
 
I think DPDT stands for Double Poll Double Tip?

Anyway this would go close

JQX13F24 24VDC H35xL20xW22 mm

You will need to slightly modify the pins on the relay to get it to fit the board.
But go with what EchoWars suggests as it probably a better fit.
 
Interesting, a double pole single throw or as they call it a 2 form A.

and with very strange forked arms...

There doesn't look like there are any contacts lined up under that smaller secondary set of contacts...


I used to work at Magnecraft (a relay manufacturer) before they moved production to Mexico. Making production relay test equipment. Measuring milliohms...
 
targeteye said:
Pics. This appears to be some sort of 4PST relay as ruesselschorf described above.

Steve
Click to expand...

Musicalme said:
I think DPDT stands for Double Poll Double Tip?

Anyway this would go close

JQX13F24 24VDC H35xL20xW22 mm

You will need to slightly modify the pins on the relay to get it to fit the board.
But go with what EchoWars suggests as it probably a better fit.
Click to expand...

markthefixer said:
Interesting, a double pole single throw or as they call it a 2 form A.

and with very strange forked arms...

There doesn't look like there are any contacts lined up under that smaller secondary set of contacts...


I used to work at Magnecraft (a relay manufacturer) before they moved production to Mexico. Making production relay test equipment. Measuring milliohms...
Click to expand...

EchoWars said:
I think it's an old-style DPDT with four contacts, and replaceable with the LY2-0-DC24.
Click to expand...
It's a four-contact DPDT relay...the NC contacts are trimmed off.

A lot of high-power gear used these back in the day. I have NO idea where to find anything like it, and I'd bet I've dug thrrough more relay catalogs then anyone here (but, if someone knows where to get them, by all means tell me).

The solder pins are a 'MY'-style (the 'LY' relays have coil pins mounted wider and turned 90°). The Omron MY2-02-DC24 (part #SW952-ND) should pop right in there (check the coil resistance of the original...it should be 630 ~ 660 ohms). The Omron MY2 relay is not rated at the same current level as that 4-contact job, but the only other solution is to remote-mount a beefier relay. Unless you're rockin' the neighborhood on a regular basis, I think the MY2 will do fine.
 
LOL @ jstang

That was something else I was thinking as well as Echowars. Mount something else and run flying leads to where the relay used to be. Not original but would fix it once and for all.
 
EchoWars said:
It's a four-contact DPDT relay...the NC contacts are trimmed off.

A lot of high-power gear used these back in the day. I have NO idea where to find anything like it, and I'd bet I've dug thrrough more relay catalogs then anyone here (but, if someone knows where to get them, by all means tell me).

The solder pins are a 'MY'-style (the 'LY' relays have coil pins mounted wider and turned 90°). The Omron MY2-02-DC24 (part #SW952-ND) should pop right in there (check the coil resistance of the original...it should be 630 ~ 660 ohms). The Omron MY2 relay is not rated at the same current level as that 4-contact job, but the only other solution is to remote-mount a beefier relay. Unless you're rockin' the neighborhood on a regular basis, I think the MY2 will do fine.
Click to expand...

Echowars,
First of all thing you very much for taking the time to help me track down a substitute relay and furthermore thank you for just being willing to share your vast knowlege of these old stereos with others. I and others i'm sure very much appreciate your efforts!

Checking the MY series specs and measuring the holes on the PCB is looks like that one will indeed drop right into the board with no modification to the board. I just have to trim off NC set of contact terminals on the Relay. I also double checked and the resistance of my existing relay is 650 ohms.

I'll get one on order now!

Steve
 
Musicalme said:
I think DPDT stands for Double Poll Double Tip?

Anyway this would go close

JQX13F24 24VDC H35xL20xW22 mm

You will need to slightly modify the pins on the relay to get it to fit the board.
But go with what EchoWars suggests as it probably a better fit.
Click to expand...

Musicalme,
I checked both Digikey and Mouser for those part numbers with no match. WHere did you find those relays and what are they?

Steve
 
jstang said:
:scratch2:only option left is to sell the amp to me.......:smoke:
Click to expand...

Had I known it was going to be this big of a pain to find parts for it I may have taken you up on that! Now it has become a labor of love I think, when I put this much work into something very seldom do I part with it :).

Next time I might just go ahead and send it to Echowars to begin with!

Steve
 
avionic said:
??? What formula are you using? Power=voltage x current
Click to expand...

uh...Guess I had a brain fart. Of course it P=I(squared) times R. 10 amps would be 800 watts! Plus the whole concept of the DC current rating of the relay somehow equating to the power output of the amp I don't think is valid anyway. :screwy:

Steve
 
These are listed as power relays in my WES components catalog. What brand they are I don't know I would have to ring them to find out. Anyway on closer inspection they have the coil pins at 90* to what yours are.
 
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