Color Classic buzz (with sound!)

[nickpunt]

I recently got my color classic put back together and there's a high pitched noise I'm trying to diagnose. I'm not an analog guy so I can't tell what it is. The sound repeats every 5 seconds or so and is louder when monitor is bright. 

I recorded it using a nice mic and pulled out the spectral frequency graph and it's hovering around 10kHz, +/- 1kHz. It has an 'X' pattern where it drops and rises linearly, which gives it a dip-and-rise sound. 



ColorClassicBuzz.mp3

Some ancillary issues are the screen starts up yellow-ish before getting to regular colors (especially after not being used for a long time, less so when started up within hours of the last time), and there's a slight pincushion shape to CRT. The board is a mystic board and has not been recapped but caps are clean and it performs well.

Any ideas on what needs fixing? Thanks!

 

[uniserver]

sounds mostly normal, re-capping the main board would be a good thing to do, those caps are toast on there.   Also the A/B could use a re-cap as well.   The only other thing to check is the flyback, they can be noisy in the CC.

 

[Bunsen]

https://68kmla.org/forums/index.php?/topic/25032-crt-whining/&do=findComment&comment=263107

http://www.colourclassicfaq.com/general/basics.shtml#Q1.1.4

http://www.repairfaq.org/samnew/tvfaq.htm