Okay, got everything cleaned up in there, but I’m having some problems here...
Look for wet looking circles around electrolytic caps and black goo on the legs (mostly the negative) of the polar electrolytic caps. Also, look for black spots on the traces on the bottom of the board. This is a good indication that electolyte has been doing its work on your board and lots of cleaning is needed.
Don’t see anything wet looking, or any black spots on the bottom of the board. There does seem to be some brown spots on the bottom of the IC board, but as noted, nothing black. Much of the brown stuff does seem to be in the vicinity of some heat sinks.
The short term fix is likely to resolder the vertical output IC, usually numbered in the 400s, often IC401 in mitsubishis of this vintage.
Seems to be precious few ICs in this thing. Most are located on a vertical board, but none of them are 400-numbers. Only one IC is on the vertical board (motherboard?); it’s not a 400 number either.
Look for solder void around the vertical scan IC(usually LAxxxx), and also connector to the vertical deflection yoke. Check if there is any electrolytic capacitor close to the vertical scan IC heatsink.
Sorry, but I have no idea what a deflection yoke looks like, and I can’t find any ICs with heat sinks (or maybe I just am not able to recognize it).
The CS-31305 definitely is one that tends to have leaky caps. They do not "dry out" but actually leak electrolyte because of faulty seals, likely made worse by high ESR and temperature, bu caps even far away from heat sinks do the same thing. It usually occurs on the negative side. There are often several leaky caps in the area near the low voltage regulators (5v & 12v). Scan the board for spots below the caps, black goo on the legs, and use the trick of heating the leads and smell for the ones where you cannot see the legs. Clean the board very carefully to prevent future problems.
Much of the brown stuff mentioned does seem to be in the vicinity of some heat sinks.
There is also a tantalum cap that causes problems in this set. IIRC it is orange and 2.2uF.
I did find a few orange looking things, kinda shaped like a mailbox. Are those capacitors? (Sorry, the only capacitors I know anything about are round like a barrel...) Some of them are near heat sinks, and there is some of that brown stuff there.
So - if the **** I'm looking for is brown instead of black, I guess I'm on the right track. Except that I can't find that vertical output IC...