Marantz 2010 Stops Playing in Stereo???

archie2

Addicted Member
All of a sudden my Marantz 2010 stops playing FM in stereo. All other imputs play in stereo. No stereo light on in FM but on for other imputs. FM plays in mono even for the strongest stations. Mono button has no effect in FM mode but does in Aux. FM comes in strong and clear over both speakers but in mono only. ????????
 
The problem is in the multiplex decoder, on the tuner circuit board. There is an IC H114 that does the job, and it's either inoperative or not getting the right inputs.
 
I'm looking at that IC, Sanyo A3310. Is there a special way to remove and replace these? They are pretty delicate.
 
Removal is not easy. First, make sure that's what is needed. If you are sure, you need some of that solder wick to get the solder away from the pins. You probably can't get it all, so you gently pry the end of the IC with a small screwdriver as you heat each pin in turn. You may have to go over it a couple of times before it's out.

Then you clean the holes from excess solder. Be very careful not to bruise the printed copper traces or create solder bridges between them. Then take a deep breath and plug in the new part. Solder each pin but give it a break after each pin or two so the internal temperature doesn't rise too much.

One suggestion is to get a defunct PC board and practice on something you don't care about.
 
"Removal is not easy. First, make sure that's what is needed."

How do you test an IC? Even if I could I'd need to take it out of the circuit to test. That looks a lot more complicated than replacing a capacitor. I re-flowed the solder on it but nothing changed.
 
http://www.nteinc.com/specs/1200to1299/pdf/nte1230.pdf

Is that the one ?


If no voltage at pin 4 it might be the IC . IF I was replacing the IC , just clip the old one and solder a IC holder into the board the insert the new one into it .



Barney

I believe it is.

This looks the same;
LA3310
Sanyo integrated circuit
ECG/NTE # 1230

I was looking at those DIP IC sockets but wasn't sure how to use them. I found a 16 pin one and the NTE 1230 IC. Heck of a lot less chance of heat damage to the IC going that route. I appreciate the tip.
 
Last edited:
I wouldn't know how to test the IC out of circuit. Just use a 'scope and voltmeter to see if its pins have the appropriate signals and voltages; if not, decide if the problem is caused by the chip or something else.

It would be a shame to replace it and still have the problem.

The idea of clipping and patching in the new one is a good one; I'd take it a step farther and after clipping, desolder the old pins and make it look like a factory job.
 
I wouldn't know how to test the IC out of circuit. Just use a 'scope and voltmeter to see if its pins have the appropriate signals and voltages; if not, decide if the problem is caused by the chip or something else.

It would be a shame to replace it and still have the problem.

The idea of clipping and patching in the new one is a good one; I'd take it a step farther and after clipping, desolder the old pins and make it look like a factory job.

That IC is cheap enough at $2.95.
 
Those chips are hardly ever the problem. 90% of the time its an alignment issue.
 
Those chips are hardly ever the problem. 90% of the time its an alignment issue.

Possibly. I watched this one go. I had a strong stereo station on and the stereo light got dim, then flickered then went out all together. At the same time the stereo sound field collapsed. I'm a noobie but I don't think that's characteristic of an alignment problem. There was no decrease in signal strength, and no decrease in the number of stations received. The muting button works as before and only selects stereo stations, except they're not in stereo any more
 
Should add that out of remaining 10%, 9% is a bad cap in the MPX circuit and not the chip. Has this unit got the complete Dexoit treatment? With muting working correctly, but with no stereo. I would suspect dirty contacts
 
Receiver has been thoroughly cleaned with DexoIT, all controls and switches. Fins thoroughly cleaned with alcohol and brush. i cannot see any bulging or leaking caps, but that doesn't meant there are no bad caps. Muting is working correctly.
 
I just noticed something peculiar. There is a resistor soldered on one end and standing on end with the other lead just sticking up in the air. It's right next to the multiplex IC in the picture. Sorry about the blurry picture but my camera only goes so close. I cannot see a soldering point for the other lead on the board. Meaningful?
 

Attachments

  • ALIM1043.jpg
    ALIM1043.jpg
    55 KB · Views: 102
Back
Top Bottom