advertisement


Volume pot on NAC82 no longer responds to remote

J

Johnny Blue

I made it to 'Member'!
For a couple of years now, the volume control on my NAC82 has been a bit temperamental when using the remote control: mostly OK, but sometimes it wouldn't budge (all other remote functions work perfectly).

I always found that one of the following tricks would get it responding again:
1) manually turn the volume control,
2) fiddle with the batteries in the remote,
3) change the batteries in the remote,
3) use another (one-for-all programmed) remote.

However, recently, it's stopped responding altogether and none of the above remedies are working.

I'm too poor at the moment to get it repaired by a dealer/Naim, and the remote not working isn't exactly the end of the world (although it is an incovenience: the volume control was pretty much the only remote function I ever used!).

Anything easy I can try to fix it myself?
 
Does a universal remote (with correct programming) still work?

If so, the 82 is probably OK, and the trouble is most likely in the remote. If other functions of the remote work OK, it is most likely the switches. If the whole remote is dead, suspect the battery, its connections, or broken wires somewhere.

Alternatively, can just buy a 2nd hand remote, if that is the problem.

If a universal remote doesn't work, then the 82 is suspect. Try measuring the voltage applied to the motor on the pot, and see if the remote (either one) can give a signal. If there is control voltage, but nothing happens, the motor may have failed, or the pot got stiff. If there is no motor voltage, I would suspect the control circuit, which will be harder to diagnose.
 
PigletsDad said:
Does a universal remote (with correct programming) still work?
Click to expand...

No.

PigletsDad said:
If a universal remote doesn't work, then the 82 is suspect. Try measuring the voltage applied to the motor on the pot, and see if the remote (either one) can give a signal. If there is control voltage, but nothing happens, the motor may have failed, or the pot got stiff. If there is no motor voltage, I would suspect the control circuit, which will be harder to diagnose.
Click to expand...

Pot doesn't feel any stiffer than usual. I'll give the voltage measurement a go.

Thanks for (incredibly) prompt reply!
 
I had 52 with this problem and it was a lazy motor on the pot. I swapped the volume motor for the balance one.
 
Hi Johnny.

If your Alps motorised pot turns out to be 'shafted' ;) drop me a PM if you need a new one - I have two new ones here.

Regards
Dave.
 
If it's the remote, I say get the logitech universal. It really works well especially if you have non naim equipment that has remote control. The cool thing is that the remote command set for naim is available in their database, so you do not need to teach it manually like the olden days universals.
 
It does sound like the motor.

I had this problem with my remote and my 82. In my case it was the remote.

Often dust, corrosion and dirt get between the conductive membrane and the pcb inside the remotes. There are some things you could check as it's only the volume that doesn't function:

  • Remove the batteries
  • In really good light check to see if there's been any corrosion of the battery contacts
  • If there has, clean it off with some very fine wet and dry paper and vacuum the dust out
  • Either way, with the battery compartment at the bottom tap the remote on a firm surface and vacuum it out

If that doesn't work you may need to open the remote and clean between the membrane and contacts (in which case PM me and I'll tell you how I opened my 82 remote which suffered from the same problem on the Mute function)
 
Thanks for the further suggestions, but I'm fairly certain it's not the remote. I recognise Mark's issues with the battery compartment and contacts: as I mentioned in the OP, fiddling with these used to make it work properly, but not now.

Also, the programmed universal remote I have, which always used to work on the volume pot, no longer manages to shift it either.

All of which points to the pot motor. I shall have to take my courage in both hands and not only open up the 82 (no problem there) but also then connect up the NAPSC to check the voltages (a bit more scary!). (And swapping the balance motor sounds like a good idea, since I never use it!)
 
Quick update:

As is my usual way, having got all these useful suggestions, I did f***-all about it, and either accepted that the music was too loud or too soft, or got up off my lazy a*** and twiddled the volume pot manually.

Every so often, like a condtioned rat, I would try the volume control on the remote just to see, as if by magic, it would work again, and of course it never did...

...until yesterday!

So, having done absolutely nothing to the amp, and after months of not working, the remote's volume control buttons are suddenly operational again (and it's still working today, just been down and checked!).

Do I need to start believing in God, or what?

Any explanations?
 
a duff connection that has corroded over time. Stop trying it and the fault gets manipulated by the temperature cycling and eventually the corrosion breaks down allowing electrons to move. (Complete speculation by the way)
 
IIRC correctly there was a EPROM upgrade for the 82 to cure that problem, you might want to check with Naim.
 
Pete MB&D said:
thickened grease geting warm in this hot weather
Click to expand...

I'll have to wait until winter to test out this theory...

...plus, it does rather suggest I live in a drafty hovel without any heating (only partly true).

cliffpatte said:
IIRC correctly there was a EPROM upgrade for the 82 to cure that problem, you might want to check with Naim.
Click to expand...

I have this pathological condtion that makes me think even phoning Naim to ask about something like this is going to cost me hundreds...
 
I'm a bit late to this thread but I've just found the cause of the same problems on my 82 that Johnny Blue complained of. I measured the voltage on the pot motor connections on the pots pcb (if you look down the back of the pcb you can see the pot motors and follow their brush holders via what look like wirewound resistors to their correspondig pads on the pcb). The balance pot (working ok) regisered 6.2 volts but the inoperative volume pot measured 7.5 v so I surmised the volume pot motor was open circuit - at least the logic circuit was ok! At that point my meter probes slipped out of place and, when I re-applied them to confirm the voltage it measured 6.2 and the pot was turning! All I'd done was pushed the meter probes across the soldered joints. I took this to be a sign of "solder fatigue" where, due perhaps to vibration, a crack appears in the solder joint which eventually completely isolates the component lead out wire from the copper track on the pcb, although I couldn't see anything with the naked eye. The pressure from my meter probes, and perhaps temperature variations when it had sometimes started working again for no reason, had been enough to restore continuity. I resoldered the 2 connections for the volume control, and did the balance control for good measure, and it's worked fine ever since.
 
Just read your "tale of woe" so understand your caution but I think what we're dealing with here is more electrically robust than the components in your CD3 and I see youv'e got a soldering iron and multimeter so you're equipped to try the job! If you remove the chassis from the sleeve you'll see the pots board at the front left (obviously - right behind the vol & balance knobs) with a screening alloy enclosure around the pots and the 2 joints you want are the 2 at the rear left hand corner of the pcb. Plug in the NACPS and try the vol buttons on the remote whilst measuring the voltage across the solder joints (lack of 3 hands explains why my meter probes slipped off!). 7.5 volts means your pot motor is open circiut, 6.2 v should be working and 0 v means the problem's in the logic circuit and that's beyond me I'm afraid. If you get 7.5 v just reheat the 2 joints with a little added solder and try again. Good luck!
 
Thanks for the clear explanation: I'll summon up the courage to give it a go (especially as the volume pot is now completely frozen, using the remote, and it's the only control I ever want to use from my listening position!).
 
As a ps to my earlier posts my resoldered connection worked fine for me for 18 months and then died completely. Investigation showed an open circuit motor on the volume pot and a search on this forum turned up a post from Mark Slade saying that the same pot that Naim use is available from Rapid Electronics (<£24) so I orderd one. I see they're also available on ebay but I wasn't sure if they would be the correct model and there seemed a nice symmetry about following Mark's lead since my POTS2 board bears a label with the builder's initials - MJS! Once I'd twigged that having pulled the volume and balance knobs off their shafts and removed the knob's "hubs" that carry the leds to iluminate the indicator bars and left them hanging by their leads it was only necessary to remove the nuts on the pot's shafts to release the complete pots board it was simple to wiggle the board out of the chassis and loosen the connector from the control circuitry to be able to access the whole assembly. I used a solder sucker to free the voloume pot (2 lugs attached to the gearbox - mechanical fixing- and 6 pot connections, including 4 flying leads on top of the pcb) and the whole pot came free. I solered in the new pot and tried the motor operation with the NAPSC connected ( the motor ran the wrong way so I had to swap the motor connections and eveything worked fine. Total time my 82 was out of the use was an hour and a half for a first attempt.
 
You must log in or register to reply here.


advertisement


Back
Top