Re: Tech Help Hitachi, 65SWX20B

If there are heatsinks on the CRT boards look to see whether the have a
three terminal device on them or an IC. If ICs it is likely that one of
them is shorted. To determine which one each CRT board needs to be
disconnected individually to find out which one.

If the snap you mentioned was from anode cap leakage you would notice
if you had disconnected the grounds, you would get zapped. It is very
unlikely to be able to disconnect all of the grounds easily, they are
redundant. If the snap was from focus voltage, well you did not
disconnect that, it usually goes right from the FCB to the socket
itself, doesn't even touch the PC board.

Sometimes ICs make a sound when they blow open, and do sound like an
arc. Therefore the first thing I would do is to physically inspect the
ICs for blow holes. This would be the quickest way to the problem. See
one, remove it and the set should run with the other two colors only.
At times they blow apart so you can't read the part number, but then
the other two do have the number, such as TDA6111Q, something like
that. Common problem if they use them.

Another possibility is that what you disconnected was the G2 supply,
but I am pretty sure that is a soft supply in those sets, so it can't
make a pop or snap. If that's the case, your meter is what loads it
down to 250V, because G2 is usually about 400V, but a meter loads it.
You wouldn't have that though, usually that will be a wire coming to a
one or two prong plug to the CRT socket board. It would not usually
come from the power board, it would come from the FCB (thingy with
either three or six controls on it).

Also, I seriously doubt whether a short on either focus or G2 would
cause the set to shutdown.

I just checked the database and there are no records for that model, is
it pretty new ? Or did you type it wrong ?

If it's really new are the CRTs still in warranty ? If so you shouldn't
be in there. If you screw anything up they might deny the warranty
claim. Because there is always a slight possibility that the CRT is
shorted. I would much rather pay someone just the labor to change a CRT
than to foot the whole bill.

Anyway, at this point, if you see TDA 6111 or 8351 on the devices on
the heatsinks, be very suspicious of them. Best I can do with the info
you provided.

JURB

.