M4 troubleshooting

[rkwan]

Hi all,

I've finally got my first set-up, and I've been having issues with low, intermittent (left or right), or no sounds coming out. I think I've pinpointed it to my M4 amp, but I can't be sure and I'm hesitant at the moment to bring it into a service shop if it really turns out to be nothing. I figured this would be a good place to start asking, and then branch out if need be. I apologize in advance if this isn't the forum to be to ask for help!

I have a Uturn TT, Kenwood Basic C2, Yamaha M4, and Polk T50. In the various times I've tried the system I get mixed results. It may start out working 100%, but one speaker will eventually stop working, and then sometimes the other one will also stop. There isn't really a pattern to which speaker stops first, and it may sometimes be both speakers that stop. I've used an Ohmmeter at the outputs, and I've had readings on the C2, speakers, and speaker wires. I get an open loop reading on the M4 but I honestly don't know what that means in this situation.

Any help would be great, and I hope I've provided sufficient and proper information for anyone could help me. Thanks a lot!

 

[clinic-audio]

Hello rkwan
I t sound to me that your speakers relays are involved in your trouble .
When music is listened , did you play with speaker knob "ON - OFF " 2 or 3 times to see if the sound is coming back or not ? If yes , that the gulty parts to replace !

 

[mbz]

Please don't take ohm-meter measurements with the unit powered ON. Sparks may fly!
I'm guessing you did not in which case, as clinic-audio is hinting, the protection relay would not be active
so an open reading is expected. Do you have any other amp that may act as a power amp via the
pre-out/main-in? I wish I was familiar with the M4, maybe something simple like deoxit of speaker
selector. First try connecting speakers to "B". Otherwise try replacing the M4 with another unit and
see if problem persists...

 

[Vint Age]

I t sound to me that your speakers relays are involved in your trouble .

My thinking too.

 

[clinic-audio]

Please don't take ohm-meter measurements with the unit powered ON. Sparks may fly !

Do not make confusion when you use your voltmeter or ohmmeter when the display said : OL
OL mean open loop yes but also Over Load and that's what you made by putting probes on speakers terminal with your meter in ohmmeter position !
As mbz said : do not do that in ohmeter position , in AC volt you can

 

[rkwan]

Thanks for reaching out. I tried what you suggested with the speaker buttons, but nothing has changed. I did start playing around with my kenwood preamp and discovered changes whenever I changed the cartridge setting, so I'll see if someone over at the kenwood section has some suggestions.

 

[mgkfifty]

I can tell you from experience, do not connect DMM set to ohms to speaker terminals with amp powered up, very bad things will happen!

 

[bmanone]

Hi all,

I've finally got my first set-up, and I've been having issues with low, intermittent (left or right), or no sounds coming out. I think I've pinpointed it to my M4 amp, but I can't be sure and I'm hesitant at the moment to bring it into a service shop if it really turns out to be nothing. I figured this would be a good place to start asking, and then branch out if need be. I apologize in advance if this isn't the forum to be to ask for help!

I have a Uturn TT, Kenwood Basic C2, Yamaha M4, and Polk T50. In the various times I've tried the system I get mixed results. It may start out working 100%, but one speaker will eventually stop working, and then sometimes the other one will also stop. There isn't really a pattern to which speaker stops first, and it may sometimes be both speakers that stop. I've used an Ohmmeter at the outputs, and I've had readings on the C2, speakers, and speaker wires. I get an open loop reading on the M4 but I honestly don't know what that means in this situation.

Any help would be great, and I hope I've provided sufficient and proper information for anyone could help me. Thanks a lot!

I had an issue similar to yours with the M-4. Early on one channel was dropping in and out, the cause ended up being the speaker relays - replacement of the relays resolved the problem. About a year later I had a problem with the left or right channel having low output - the issue was caused by the DC AC Mode switch on the back - disassembly and thorough cleaning the switch resolve the problem. I hope this helps.
Barry