Karaoke Forums

We have a Yamaha MG124cx mixer that is not quite a year old. Last night the stereo and group out went silent (all lin the same bank). Some of the other "outs" worked but not so that we could get any volume without screeching so we had to borrow a mixer to run the show. We live on a very bumpy road so the boyfriend is suspecting something came loose and is about to do surgery. I am worried about voiding the warranty (if we have one). Any ideas before mixer guts are all over the house?

If it's less than a year old it is under warranty. But get it in soon -- it's a one-year warranty.

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[color=#ffff55]Mickey J.[/color]
Alas for those who never sing, but die with all their music in them.
-- Oliver Wendell Holmes, Sr.

Just looked it up and the warranty expired on 8/20. So far no loose wires or connections found.

How about a timer?

Are you absolutely positive that the group/stereo buttons are depressed?

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[color=#ffff55]Mickey J.[/color]
Alas for those who never sing, but die with all their music in them.
-- Oliver Wendell Holmes, Sr.

I would take it to a nearby shop or audio store before writing it off just in case it is user error. I thought my LX7ii was a goner once until I realized one of the guys I work with (who are the cause of all my technical problems, grr!) had hit the standby button, which replaces the mix outputs with whatever is coming in on RCAs.

I understand what you mean by bumpy road. I bought shock racks for my rack gear and when I transport the LX7 it goes in the truck instead of the trailer.

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Jeff Wheeler, moonlight DJ/KJ

Thanks--I will forward to the boyfriend and have him check those things. Doesn't seem like it sould be working one week and just not turn on the next unless something got pushed by accident but he may have already checked that stuff. He is also going to call Yamaha today and see if there is a repair place near us.

Alright. boyfriend here.

After getting it apart (28 nuts and washers andI think 26 screws and 11 slider tabs, plus the srews holding the circuit boards in) and putting it back together because I found nothing out of the ordinary... The stereo out does not work still but the group 2 has output but group one does not.

I am the first to look for operator error when this stuff happens but unfortunately this is not the case this time.

Which part should I bang on with the hammer???

J/k

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Kevin

I took it apart again and put on some glasses and got better light and found there is a crack in the top circuit board right where the sound doesn't work. Stamped on the crack in ink is "OK T21" which means the crack was always there but that the board was tested and it worked. I called Yamaha and the part would cost $174.37 plus shipping and coming from Japan in 4 to 6 weeks.

I am a bit pissed that Yamaha would sell a product like that. They would have to know that the crack would fail sooner or later.

Oh jeesh, I can't say pissed on this board? Oh well, better to be pissed off than pissed on.

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Kevin

True, true. Just like there is a big difference between peeing IN the pool and peeing INTO the pool.

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C Mc
KJ, FL

And of course it is better to be pixxed off than pixxed on.

In the case of a "cracked" or "open" open path on a circuit board I would first confirm with an ohm meter that the circuit is in deed open. If it is I would trace the circuit to find the closest solder point on either side of the break and then solder a jumper wire between the two points. I've done this many times over the years with a great deal of success. a little time and a little solder is much more cost effective that $174.37 in my book

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Quickness of mind will deceive the eye

Yes, I have checked it with an ohm meter and ther are 8 broken paths of which I need 6 of them. I have been debating whether to attemp wiring it myself but it looks like a couple of leads go to some tiny diodes and I will have trouble heating there. It may be that I will be able to put all three leads at one point because I find I have a closed circuit between the diodes and the jack solder point. I may need a smaller tip for the gun also.

There are also places that will fix broken circuit boards and I am considering that also.

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Kevin

Yes, it can get pretty touchie but I've always figured that hex, it's already broke. I usually use a 24 gage solid core wire and I picked up a pair of them cheap reading glasses at the dollar store. The strongest I've been able to find is 3 1/2 but they sure help when it comes to seeing the circuits. Good luck.

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Quickness of mind will deceive the eye

I appreciate the advice. Yup, got the reading glasses right here (that's how I saw the crack) but the solid core wire just may do the trick and I hadn't thought of that.

Thanks

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Kevin