DIYbanter - View Single Post

On 14 Jun 2006 17:43:31 -0700, wrote:

There is no way all the STKs failed at once. Ask the customer how long
the set was running when this happened. If it was a very short time you
might just need caps in the DCM (DCU). Problem is the data are
scrambled now. In other words the reset routine didn't work right.
The customer said that he was watching a movie on his vcr and then was
going to watch TV. When he was switching from antenna 1 to antenna 2
he hit the power button by mistake then immediately hit the power
again to turn it back on. So I would guess that it was on for at least
an hour.

I wouldn't be afraid to try a blank EPROM in it before ordering the
DCM. Thing is, you better be good at convergence.

We got one of these sitting at the shop, and the crosshatch pattern is
like art, it really is. It came in with dead STKs but after replacing
them we know the DCM drove them to death.

Anyway, a new DCM will require full alignment so an EPROM might be the
way to go. Actually if you could just find a way to erase the EPROM in
there now you might be alright.
I think I'll try a new EEPROM and see what happens. If a new one makes
a difference then problem solved, if not I'll put the old one back in.

If you can adjust any of the convergence, see if it actually adjusts
the point where the cursor is, if not, screw it, get a DCM. If it
adjusts the wrong place on the screen the processor is probably
screwed, and having a major change when you change the EPROM doesn't
indicate anything else.

Actually I succeeded once in aligning one that adjusted the wrong
points on the screen and it never came back.

Let's put it this way, the DACs are seperate so all of them did not
fail at the same time, the main processor(s) and the EPROM are what are
common to all colors.

If, and it's a big if, you can align it, just check all the lytics and
realign it. Problem is you might not be able to align it. If you can at
that point it'll probably nevrer happen again.

Actually $107 isn't all that bad, if it's high definition, wait until
the scan convertor (hyper module) goes !

Don't worry about the blue focus, for one it doesn't have to focused
all that tight, and in some sets needs to be defocused to achieve color
temperature. Of course the optical focus is set dead nuts, but there is
an offset for the electrical focus. Going slowly through the range of
the electrical focus, the blue should darken a bit. This is perfect
focus and that is when you do the optical focus. Then you again offset
the electrical focus. This only applies to blue on tri-CRT projection
TVs.

JURB
With the self diagnostic check saying the SET ID is FF instead of 01
and the EEP VERSION as FF instead of 02, I am leaning towards a bad
EEPROM
Thanks
Ray J