Tecsonic Super Jumbo works like a theremin!!

[brixcase]

Hi all boombox heads,
i have had a Tecsonic SuperJumbo for years but it has sat in the loft for the last 10.
since i last used it there has clearly been some deteriation as there is an audible feedback-like buzz when powered on but idle.
Audio via AUX plays (actually sounds great) and i have done my best to dust and clean the sliders with contact cleaner as best i can (i really dont want to dismantle the entire internals to get to the back of these controls, which are obscured by circuit boards!).
when i move my hand closer to the volume control the buzz gets louder, and quieter as i move it away... almost like a budget theremin!!
if i touch the headphone jack which i right next to the volume slider i get clicks which leads me to believe that the issue is with some sort of short or bad connection with the headphone jack.
can anyone suggest a likely cause or do i just have to bite the bullet and start dismantling stuff? please note i am NOT experienced with electronics, but dont mind poking about a bit!
thanks in advance,
nige

i was going to post a video of this to accompany this but its pictures only i now realise...

 

[DPaignall]

Most problems with older cassette players relate to the 'record bar', it's a switch connected to the record button, most signals go through it. Over the years the contacts within the bar get oxidized and need cleaning with deoxit or a similar electrical cleaner. If you don't want to take the unit apart to clean the switch then pressing the record button repeatedly can dislodge some of the gunk. Good luck!

 

[brixcase]

thanks for the info. really appreciated.
i had a look for it but on the jumbo i think it is on a secondary circuit board and not readily accessible.
i dont suppose anyone out there has a service manual for this model? cant find it on analogue alley...

 

[DPaignall]

You're right the record bar is inside but you can still press the record button (usually next to the play button) repeatedly to help clean the switch. I can't find a manual for it either.

 

[docs]

Leave the deck door open and engage the record tab in the top left? Corner and press record stop a few times see if it changes it