Modern Mitsubishi projections.How does the fluid expand?

[JCFitz]

Working on probably the the hundredth modern Mitsubishi projection with fluid leak I've had to deal with. Usually the seals aren't bad it's just that they're bulging at the seams with fluid. You can see the rubber expansion seal practically bulging out the hole in the cover.

Usually I just remove each tube and make the seal concave while draining some fluid and it doesn't leak again. I just wonder if these are overfilled at the factory or the fluid expands over time? RCAs have a similar problem though the expansion seals seem to be made of natural rubber and they crack or get holes in them. Not so with Mitsubishi.

Luckily this one didn't cause too much circuit damage. Just a blown pico fuse because it leaked on the convergence circuit.the STK might be bad.I'll have to see when the washed pc board drys out.

[mbates14]

ive actually had them leak around the gasket, as the metal tabs where the spring loaded screws go, "bend" and cause leaks.

[kx250rider]

I hadn't seen any Mitsubishis do that during the time I was still working on them (stopped about 2004), but I saw it a lot in Phillips and Sony projection sets for years prior to that... I never tried to refill or fix; I just replaced the CRTs or would decline the job if the customer didn't want to spend for that. I saw too many refunds take place when a CRT would redevelop a leak in a week after a PAINSTAKING fix-it job on the coolant seals.

Charles

[mbates14]

speaking of mitsubishi, i just did a tube swap today from a 55511 to a 55413, and didnt notice bulging expansion chambers.