Denon PMA-980R and problems with input selector? Here's the fix!

SuperKris

SuperKris

Vintage Hi-Fi
When you type PMA-980R on google you get a lot of hits about a problem with the input selector. Thats a shame, because its a real nice amp.

I hope you all find this post when you have problems with your own pma980r.

This is for when you input slector jumps inputs like crazy or maybe wont work at all. It has nothing to do with you relais going bad. Its just the wear on the switch.

Anyway, here is how you can fix it. Is very easy.

This is all you need.

- A solder iron + solder
- a screwdriver
- contact cleaner
- 30-60 minutes of time

Here we go!

Step 1:
- take the top of the denon.

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Step 2:
- unscrew the ground from the front panel.

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Step 3:
- Pull off the volume button.
- disconnect the volume button light

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step 4:
- unscrew the black screws at the top of the front panal
- unscrew the black screws at the bottom of the front panal

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Step 5:
- pull of the speaker and the input selector buttons
- inscrew the bold behind it

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Step 6:
-carefuly pull of the front. I prefer to put the amp on the side.

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Step 7:
- Disconnect the PCB on 2 sides from the rest of the black front

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Step 8:
- Disconnect the PCB from the rest of the amp

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Step 9:
- This is the switch we need to fix

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Step 10:
- Take the solder of the big pins and bend them straight

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Step 11:
- pull off the part from last step


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- This is the hardest part. You have to bend the metal back that holds the metal part to the brown part. Be carefull with the brown part, it breaks easy!

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- pull of the green disk.

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Step 12:
- You can see the switch is really dirty. Clean it out usinf contact cleaner. Personaly i also used some steel wool (i hope you call it like that in english), but be very carfull not to scratch the steel too much.

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Step 13:
- clean the small metal part on the green part.
- bend the metal part a litte bit more out, so you can be sure it will touch the disk of the other part.

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Step 14:
- put the switch back together. IT will be very hard to bent the upper metal part back. Be carefull not to break anything. Its not very important you get it perfect. There is always the metal strip that holds it in place.
- bend the metal strip back, and solder it again

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Step 15:
- put everything back togeter! Be carefull with the LEDs close to the selector buttons. Make sure the go in the right way.


Now everything should be working again!!!

Good luck!
 

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Bonjour

Thank you a lot for this post and to help to solve this problem with this ampli I like a lot.

May I ask something else to you?

When I push the volume at a high level I get a big "paf" like an explosion in the loudspeakers, is it the big condensator to change? or is it normal when I push to high? or is it somewhere in this forum an answer for that trouble.

In any case nice from you for your clear explaination above. Nice job

Give feed back when I will finish my repairation:

Cool Guy!

Greetings

Jarry
 
SuperKris said:
When you type PMA-980R on google you get a lot of hits about a problem with the input selector. Thats a shame, because its a real nice amp.

I hope you all find this post when you have problems with your own pma980r.

This is for when you input slector jumps inputs like crazy or maybe wont work at all. It has nothing to do with you relais going bad. Its just the wear on the switch.
Click to expand...

Hello SuperKris,

My dad's old amplifier is the Denon PMA-980R and this sounds exactly like the trouble we got with the input selector.
I am not sure if we had the same problem with the speaker (A/B) selector and I am also not sure if there was another problem.
Plus the fact that I am a complete newbie at repairing stuff like this.

Still, after searching the internet and merely finding problems and no solutions, I am really glad I came across this topic.
Your solution sounds like a good one and I am going to try and work it out together with a mate soon.
So, when the repair is 'done', I'll make another reply and say thanks... or just shout out loud how sad I am that I crushed this wonderful amp ;)

Regards,
Marvin
 
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Ok, good and bad news.
I followed all steps, together with a mate and my dad.
Step 11 was hard ('This is the hardest part. You have to bend the metal back that holds the metal part to the brown part.'), everything else went smooth.
We remembered trouble with both the input selector and the a/b speaker selector, so we didn't run any test and just cleaned them both.
Except from the tuner led light on the input selector that broke, all trouble here are fixed.
So far, so good, I am already really happy that we got this done.
But there is no sound coming out of my speakers when I hook everything up.
So, no sound output from my amp.

Anyone got any clue what else could be wrong?
Everything seems fine...
 
SuperKris said:
do the input selectors work? can you select one and will the led of that input work?
Click to expand...

Yes, the input selector and the a/b speaker selector are both working now.
I can switch inputs, the leds work (except for 1 I guess I broke, the one on tuner).

My dad and I gave it a thought and we remember that first the a/b speaker selector started acting weird, then the input selector started acting weird as well and when this problem became bigger and bigger, after a while we had no sound output anymore.
But this is years ago.
My dad opened up the front one day, but didn't find anything.
It is just this week that I followed your guide and fixed the trouble with the input and a/b speaker selectors.
But I am still with the problem of no sound output.

I am a complete newbie at this, but I can't believe that there's a big chance that something else in the amp died pretty short after the selectors were acting weird.
That would mean 2 separate problems on an amp that was like 10 years old when it started acting weird.

I called a mate who's going to borrow some equipment from someone and then I need to find the manual so we can do some more work.
If we can fix this I'll be delighted!
 
If i can help email me. I dont have the amp anymore, but i do have the service manual. My mail is kristiaan83 (AT) gmail (DOT) com. Ik ben ook nederlands, dus doe geen moeite met engels enzo.
 
Thank you for taking the time to write this tutorial. I'll try to do it this weekend. (This has been driving me crazy for months!)
 
Thanks for this very detailed guide to fix the problem. It has been a problem for years. Did the fix today, and the amplier has played the last 5 hours without any problems - THANKS :banana:
 
That's great. I've got a Denon reciever with the same symptoms as described. I'm gonna give it a shot as you described. Thanks for the pics. :thmbsp:

Jimmy
 
Sorry, I have the same problem for the "speaker selector". Is the solution equivalent? Thank you very much!!:scratch2:
 
They use the same type of swich, so if the problem is the same with the sellector jumping like crazy it very likely the problem is the same, and this fix will help you.
 
:banana:Repair has been made. Everything is working perfectly again. Thanks a lot. That's great!!!:banana::banana::banana::tresbon::tresbon:
 
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