Hello all. I bought a used ds939 that worked fine till recently. No left channel on A or B. Switched speaker cables to verify it's left only. I'm fairly familiar with electronic parts. I have my own ohm meter and can soldier. Any help on where I should start looking for issues would be appreciated. Thx
My guess would be the speaker protection relay. Repaired a few of these and the contacts are very soft they bend out of alignment especially if the unit has been left on for long periods. Some types of relay have snap on covers so once you have got to them you can open them up and realign the contacts. A warning before you dive into the unit, mains voltage is all over the power supply board so remove the mains plug from the wall before you start.
If it is the relay, and there is one relay for each channel, it could be open "on purpose" because of
a circuit fault triggering it to open.
If however the relay is shared between channels, then the relay itself is the problem.
a circuit fault triggering it to open.
If however the relay is shared between channels, then the relay itself is the problem.
If I recall correctly these Onyko receivers use one relay for each of the main Left Right and Centre channels but share relays for the surrounds. You're right rayma it could be a circuit fault but in my experience it has been the relay failing to make contact. That is where I would look first.
Yes, and maybe both relays will open even if there is only a fault in one channel.
That would be the safest way to connect them.
That would be the safest way to connect them.
I see 3 relays. First one connects ac line, its smaller. Next to small yellow trafo.
Then close to speaker outputs are two other, one says 12V DC.
Then close to speaker outputs are two other, one says 12V DC.
Usually they are directly behind the speaker sockets. Agree the service manual is not a lot of use when it comes to the layout except the block diagram does label them.
RL5361 L/R A
RL5641 L/R B
RL6533 Centre A
RL5634 Centre B
RL5633 Surround
RL5642 Surround
Attached pic shows speaker relays on the ground floor, cant see what boards were on top.
As the manual shows separate relays for the A&B outputs the problem may be with the amp. Check that white connector with the pink and white wires is seated correctly. Also check none of them have become detached. Check the vertical black ribbon cable at the bottom right of the board it does not look to be seated correctly.
RL5361 L/R A
RL5641 L/R B
RL6533 Centre A
RL5634 Centre B
RL5633 Surround
RL5642 Surround
Attached pic shows speaker relays on the ground floor, cant see what boards were on top.
As the manual shows separate relays for the A&B outputs the problem may be with the amp. Check that white connector with the pink and white wires is seated correctly. Also check none of them have become detached. Check the vertical black ribbon cable at the bottom right of the board it does not look to be seated correctly.
Attachments
That black cable actually seems loose. How do you release the cable so I can reseat it. My eyes aren't great and don't want to force anything. Thx
If your eyesight is not great don't fiddle with the mains lead plugged in. There is a live cable and exposed fuse holder at the top of that board.
The black cable has a clip that is held at each end, you may need a magnifier and then a small screwdriver. Release the clip at both ends, push the cable back tight and pop the clip back on.
The black cable has a clip that is held at each end, you may need a magnifier and then a small screwdriver. Release the clip at both ends, push the cable back tight and pop the clip back on.
Sorry if I reopen this but I have the same problems with my TX-DS 939 and am looking for a replacement relay cause the in the Service Manual mentioned "nrl-2p5a-dc24-098" and "nrl-2p5a-dc24-095“ arent available anymore. Any help for a fitting relay?
Depends where in the world you are but Digi-Key and element14 both had offerings when I Googled those relay codes.
24V DC coil relay with a particular size and contact configuration.
Should be available in Omron, O/E/N, and other brands.
It is a common item, and think of putting the highest current rating in the available size for longer life.
You can even go for relays with clamp mounting, and use wires to the PCB if all else fails.
Should be available in Omron, O/E/N, and other brands.
It is a common item, and think of putting the highest current rating in the available size for longer life.
You can even go for relays with clamp mounting, and use wires to the PCB if all else fails.
Thank you guys for the help. I successfully replaced it.
For all the others out there that may be looking for a fitting replacement:
Left one is the original and the right one is the one i replaced it with: OMRON G2RL-2A-24VDC.
Interestingly the original is an "DEC DG2SU 24VDC". That label differs from the Service Manual and they can still actually be found. I should have looked inside the TX-DS 939 first but the repair went well with the Omron and I am happy.
For all the others out there that may be looking for a fitting replacement:
Left one is the original and the right one is the one i replaced it with: OMRON G2RL-2A-24VDC.
Interestingly the original is an "DEC DG2SU 24VDC". That label differs from the Service Manual and they can still actually be found. I should have looked inside the TX-DS 939 first but the repair went well with the Omron and I am happy.
I just ordered a pair of Omron G2RL-2A DC24 for my Onkyo TX-V940. I noticed in the service manual, bottom view of the PC board, that there are dual footprints for the relays, so that 2 slightly different form factors are supported.
Was it a chore removing the old relays? Did you use solder wick? Is the PCB plated-thru?
Was it a chore removing the old relays? Did you use solder wick? Is the PCB plated-thru?
I just picked up a TX-8211 for $10. Both A channels are good but the left B channel does not work. No visible signs of anything bad on the board so I'm suspecting this relay to be the culprit. My question is, where there are only 2 relays but 4 speaker outputs, I'm assuming the channels are shared, then how is the left A channel working but not the B if they are going through the same relay?
So as it turns out, the left B channel is just a bit lazy. I cranked up the volume to around halfway and it kicked on. Startled the heck out of me and probably the tenants next door and upstairs as well. If I turn it back down the channel stays working but if I shut the unit off, when I turn it back on at low volume the channel won't work again until I crank the volume up enough to get it to kick on again... Very strange. I've never encountered this behavior with an amp before. It doesn't effect the A side, it only happens with the B side left channel but I can repeat it every time I shut the receiver off. Could this still be a screwey relay, or should I be looking at something else? I removed the board from the chassis and looked it over thoroughly and there are no visible signs of a problem top or bottom but I did find traces of what looks to be solder and possibly silver wire but it was super fine but no sign of any damage to the board, jumpers, capacitors, the transistors, heat sink, etc. It's actually in really nice shape for it's age. minimal dust and very clean throughout.
Drill a tiny hole in the relay if the cover cannot be removed, and spray contact cleaner through it, then tape over as dust protection.
Check the capacitors in the signal path and power supply, sometimes they are lazy.
Replace if more than 20 tears old, with good quality Japanese / Sprague / Vishay or similar, no ties to any brand mentioned here.
Check the capacitors in the signal path and power supply, sometimes they are lazy.
Replace if more than 20 tears old, with good quality Japanese / Sprague / Vishay or similar, no ties to any brand mentioned here.
The original relays are underrated with only 2A contacts (and probably wrong contact material). The Omron G2RL-2A-DC24 is better and has silver alloy contacts. Still a 10 or even 16A version would have been possible too. Sanding/cleaning the old relays contacts is wrong practice and futile just like replacing the old relay for exactly the same "original" 2A type. Apparently the choice was based on cost cutting decisions at Onkyo.
Just make sure to choose the fully sealed version of the relay (the ones with resin at the bottom), that pays off as no dust/dirt/moist can enter the relay. Chances are likely it will practically never need replacement in the future then.
Tip: defective underrated relays can have intermittent issues that are annoying and urge the owner to do something directly but they may also exhibit hardly noticeable too high contact resistance or even diode like properties creating distortion. As they are on their way out anyway always replace them in both (or all) channels.
Just make sure to choose the fully sealed version of the relay (the ones with resin at the bottom), that pays off as no dust/dirt/moist can enter the relay. Chances are likely it will practically never need replacement in the future then.
Tip: defective underrated relays can have intermittent issues that are annoying and urge the owner to do something directly but they may also exhibit hardly noticeable too high contact resistance or even diode like properties creating distortion. As they are on their way out anyway always replace them in both (or all) channels.
Last edited:
