APC40 fader issue and high-pitched hiss (hello KVR!)

[BetaAltairVII]

So hi - I've seen this forum before and I thought that since things seem to get quick replies here vs. the help section on the Ableton homepage, I'll put my question here. A bit about me first: I'm a 19-going-on-20 diehard fan of trance and electronica, and a budding producer/DJ-to-be with a SoundCloud:
https://soundcloud.com/transmissionsfromaltair

My DAW is Ableton Live Suite 9, and while all my stuff to date was done with mouse and keyboard I recently acquired an Akai APC40 secondhand, from a man who had had it in storage for a number of years after it was given to him by a DJ friend. It's in decent shape - one of the rotary encoder's caps is missing, some of the buttons are a bit sticky and need to be pressed a lot in order to loosen them (I could probably clean them easy if I removed the casing), and faders 1, 3 and 4 are somewhat bent, but still work. I haven't played with it much yet, but everything seems to work well, except for:

The channel 5 fader. It can move mechanically alright, but in Live itself it cannot move the fader of any channel it's assigned to past about -57 db if I turn it all the way up. The maximum varies between this and -64 db, seemingly depending how hard or fast I move the fader. This is also true if it's MIDI mapped to anything else, and if the MIDI range is reduced to inf-minus 60 to compensate.

As well, there is a prominent high pitched hiss coming from the device. It seems to be generated by the LEDs - the more that are active (whether from clip lauch buttons or encoder LEDs) causes the sound to get louder. I confirmed this by loading the entire 8x5 grid with clips, then duplicating it into an empty grid and moving back and forth - the sound got progressively quieter as less buttons were active. As well, the sound distinctly oscillated in time with the flashing LEDs when a scene was triggered.

So is it possible to fix the fader issue with the replacement parts I've managed to track down? Is the hissing fixable, or is it a design flaw (a benign or serious one)? I can live with just about all the other things I listed about the controller, but the fader issue must eventually be fixed, for obvious reasons. Does the fader fix require something more extensive? Is the unit just defective and should I try to return or replace it? Any and all replies would be much appreciated - I need to know how I'll deal with this, and how much that'll break the bank!

[gassle]

I bought and returned 3 APC40's because of that high pitched noise coming from the units. Some people don't seem to hear it or get bothered by it, but I couldn't stand it.

[BetaAltairVII]

I think I'm able to stand it - it's like the sound an old CRT TV makes that you forget after awhile, and only remember when it stops. If anything, I need to know about the fader.
Has anyone else had a similar issue? Did replacing the fader on the circuit board work?

[BetaAltairVII]

Does anyone have a solution? Maybe all I need to do is remove the casing and clean the fader unit, like my Dad has suggested?

[horsma]

some of the buttons are a bit sticky and need to be pressed a lot in order to loosen them

I'm no expert on electronics but it sounds like someone has knocked down some drinks on top of it and it is causing the noise and stickyness (connections messed up) so i would clean it first and see if it helps. Fader that's not working probably has to be changed. Replacement faders can be bought from Mouser relatively cheap. Mouser Part No: 688-RS45112A400G Beware of postage costs though.

[BetaAltairVII]

some of the buttons are a bit sticky and need to be pressed a lot in order to loosen them

I'm no expert on electronics but it sounds like someone has knocked down some drinks on top of it and it is causing the noise and stickyness (connections messed up) so i would clean it first and see if it helps. Fader that's not working probably has to be changed. Replacement faders can be bought from Mouser relatively cheap. Mouser Part No: 688-RS45112A400G Beware of postage costs though.

Anything anyone would suggest as a cleaner for that? My Dad kept saying stuff about "IC Spray" which is what circuit board cleaner used to be called back in the day, apparently...I wonder what they call that now...