Realistic PRO-26 Clicking / Buzzing [Video]

I've got this Realistic PRO-26 [not this one - another one] that suffers from a constant clicking / buzzing noise. It's there as soon as the scanner is turned on, and only stopped when its turned off. The radio does seem to stop on known frequencies but nothing can be heard other than the clicking noise. I really want to fix it. I've seen this problem talked about in a few places online, with a few potential fixes suggested.

My PRO-26 was dirty as hell and looked like some sort of liquid had been spilt on the top on and around the volume / squelch and earphone jack. So I think some of that liquid could have went down the earphone jack hole and messed things up. I have opened the radio up but could not see any obvious damage. 

I'm going to investigate further. Maybe take off the top knobs [volume, squelch] and give them a good clean. Same with the earphone jack if I can manage to get in there.

Here is a example video of the clicking / buzzing noise from my receiver for reference. Or, if you have the same problem yourself. Note: the noise happens when using the normal speaker and when headphones are plugged in. It just comes through the headphones instead when they are plugged in. Weird.

Could possibly be something on one of the boards inside me thinks. Maybe something has burned out / failed and needs replacing. Help me if you know exactly what this problem is and how to sort it out. Send a comment. Thanks. I have to admit though. In the post I linked to at the top of this post, I talked about how I didn't like this scanner at all. 

But after having this broken one, the scanner has grown on me a little. I think I now want another one. One that's in full working order. I might just hold on to this broken one and see if I can get another one being sold cheap for spares or repairs, then make one good fully working Pro-26 out of the two.

Problem is, when will a another one being sold as parts only come up for sale. I may have a long wait. I'll be keeping my eye out though on eBay. Or if you, yes you, have one that is knackered but might be good for parts that I need [possibly the first main board inside - a straight swap over] send me a comment / message. UK only though, as I'm not paying customs fees / taxes plus expensive postage from USA or Canada. If I do that I may as well just buy a fully working one from eBay UK for £60 - £100.