Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems G91A Volume Control Knob 'Noisy'

Hi,
My G61A DVD Audio Player Controller Tuner has developed a problem with using the front panel volume control knob to adjust the volume. It has gone 'noisy', so if you rotate the knob clockwise to increase the volume then the volume may jump down instead of up. Similarly rotating anti-clockwise may result in the volume increasing instead of reducing. In either case when continuously rotating the knob the volume jumps about. Generally it does head in the right direction but not always!

I'm not sure how the volume control knob works; it could be a continuous potentiometer or some sort of mechanical, magnetic or optical detection mechanism. I'm going to take it apart to try to clean it as I suspect it is full of dust and cat hairs. But it would be good to know beforehand if anyone else has experienced this problem or knows how the volume control knob works?

Thanks
Adrian

Hi Adrian,

This is a fairly common issue on G-Series...

The volume control is a rotary encoder from Alps. It is not a potentiometer and is sealed, so trying to clean it will be fruitless! The only solution is to replace the rotary encoder.

Feel free to drop me a PM if you would like more information.

Cheers,

Steve

Hi Steve, thanks for the info.

When I was working, Alps used to have a good reputation. But then the G91 is getting on a bit - it's already on its 3rd power supply
And it runs pretty hot, which is never good for longevity - I keep thinking about adding some extra ventilation, maybe a small very quiet fan.

I'll PM you.

If it hasn't changed since the days of the G68, it can be cleaned - carefully. I had a similar issue with the volume knob on my G68 which would occasionally move the volume in the opposite direction as I wanted and was generally a bit sluggish and unresponsive.

On the G68, the volume control is right at the end of the circuit board. After carefully, removing the board I covered the display part of the board with a small plastic bag and sealed it with tape so just the control knob portion was exposed. I then immersed this end of the board in high purity ethanol (methanol would also be OK) and rotated the knob back and forth for several minutes. After drying, I reinstalled it and it worked perfectly.

Hi Cliff, thats interesting. Implies that something has got inside and the alcohol has washed it away. Or maybe some of the lubricating grease on the spindle has worked its way to somewhere it shouldn't be? Nearest thing I've got to high purity ethanol is a bottle of Navy Strength Gin at 57.5% vol. But I'm not wasting that so maybe I'll try the Meths instead

Yeh, I put down to the build up of dirt from one source or another.

If you do decide to give it a go, I would only use a relatively pure solvent with no additives that might leave a residue. I believe Amazon sell methanol that is fairly pure.

Yes, I've got a bottle of Meths that I've had for years that I use for cleaning stuff occasionally. Has always worked Ok so far.

Some meths formulations leave a significant residue so be careful.

Hi

I have to say that my G68D, which bought new from Phase 3 in Worthing, never really worked properly. It wasn't an issue because it was in a cabinet and I only used the remote to operate but potentially you can cause more issues with trying to clean it, which is essentially a sealed unit. Better off replacing in my view.

Cheers

Jon

Ok, does anyone have the ALPs part number for the encoder so I can try and source one before taking it all apart (10,000,000 screws!)

Hi Adrian,

The ALPS part number is: EC11B202440M

If you're handy with a soldering iron then it can be replaced after you've undone the 10,000 screws that hold the unit together!

Be extremely careful removing the display board assembly as it has a sticky pad that fixes it to the front glass - that can peel away the black...

Good luck!

Cheers,

Steve

Thanks for the part number Steve.

I've done a quick search but it appears to be discontinued. Various places such as RS list it but have no stock and don't know when they will. And its not listed on the ALPs website. I've messaged them to find out if they have a replacement part.