Hello zainka,
With virtually any electronic equipment used in boats, oil rigs etc. will, after time, cause corrosion and rust due to
the salty air environment. Even beach front and outer housings from coastal areas eventually succumb to the salt air.
I have seen many a TV, VCR etc. having to be written off due to rust and corrosion from houses close the the sea.
Equipment in a boat would be much, much worse.
I don't mean to discourage you, but the best you can do is to open up the TV and give it an extremely close inspection.
Main corrosion will be seen on jumper wires, resistors, transistors, capacitors etc. legs, as well as rust on screen shielding material
in and around the RF, power and CRT circuits.
Dry joints are very common in salty air environments, especially in higher current areas of the set. In most cases it may look like a dry joint
but its actually crystallized the solder and is harder to remove or resolder.
There is also the possibility that it may be a capacitor problem as you've suggested, but without removing the entire chassis and
inspecting it, for not only cap faults, but more importantly for the corrosion and its possible future effects.
If you do find extensive corrosion, then you would need to clean ALL the surfaces with a toothbrush and isopropyl alcohol. Especially
areas where you see green colored corrosion buildup.
Once everything is relatively clean you can spray the areas with CRC or a similar product. Must be non-conductive at the same time,
provide an oily type coating. Wipe off any access with a clean rag.
Also pay particular attention to the bell of the picture tube (the aquadag), as this will definitely have salt laden deposits on it. Same thing, clean it with
a rag and a very small amount of isopropyl on the rag, then spray that with CRC, but make sure you wipe off all the access.
One thing though, wipe the aquadag gently as to not remove any of it.
The next thing you must look at is the ultor cap. It must also be cleaned, then prior to refitting it, use some non-corrosive silicon sealant. This will prevent
arching.
I hope the above may prompt you to check the set out sooner than you might intend, and once again, I don't mean to put you off, as the TV could still be
salvaged to keep you entertained for a few more years to come.
Regards,
Relayer