Sega rally 2 problems and modification question

[Macresco]

Hi

 
I've recently bought a Sega Rally 2 Twin cabinet. I knew it needed some work but overall it tested fine when I went to purchase it. Shortly after some issues have popped up and I'm looking for people with some suggestions what the cause could be and possibly how to fix these issues.

Firstly the right side of the cabinet wouldn't always start up right away. I usually had to give it some time. I've placed this cabinet in my garage because of place and noise reasons. This garage is not heated. I've heard that the cold could be a reason this problem occurs. Now in the last week the right side boots up without a problem but the left one just doesn't boot anymore at all. The screen seems to be turning on just fine but the board under the seat shows no signs of life.

 
Second problem is a sound issue. Recently the front speakers started making this noise

This has just evolved to this sound

It seems that the normal sounds also play through these speakers but are just adding this. Are these speakers ready for scrapping or is this fixable?

 
Third issue and kind of fourth issue is that one screen has some serious blooming(?) issues seen here

it also has quite low sharpness in the bottom right corner (and maybe the other corners but this corner was obvious because of some digits not displaying clearly.) I tried to negate this and some colour issues a bit by trying to adjust the potentiometers in the back but as soon I turned on one the white part came out.

(sorry for unsharpness but you get the idea)

Is this fixable or do I need to replace the potentiometer? I'm very reluctant to do any work back there because of the potential dangers with the anode. I've seen enough youtube videos and they all warn about this so much that I was even hesitant to go and regulate the potentiometers.

 
Any info on these problems would be greatly appreciated.

There's also the question that it's apparently possible to disable the neutral in a Sega rally shifter. I can't find info on how to do this. Is there anybody here that might know how this is achieved?

[buttersoft]

Can't answer most of those and i've never owned an SR2 setup, but the monitor streaking either needs the brightness and contrast adjusted, possibly including the G1 control i'm guessing is on the neckboard. This will need to be done live, so be careful. Or, if you can't get a bright enough picture this way without streaking, you could try recapping the neckboard, especially the big electrolytics.

Heads do fall off that style of pot. A lot of the time you can either press the head back on, though it will always remain loose and probably fall off again soon, or just use a screwdriver in there without using the head.