On Fri, 07 Jan 2011 14:06:59 -0600, David wrote:

"Chris F." wrote in message
. ..


This Samsung HCN4767W projection set is really making a nuisance of
itself. It had a blown convergence IC when I acquired it, so I replaced
them both. It ran for a few days in the shop (about 6-8 hours a day),
then blew one of the same IC's again. I replaced them again, and also
replaced the convergence processor board. Again, it seemed to work fine
for a few days, but now the bloody IC's have blown again. The supply
voltage to the IC's is a solid 25V (pos. and neg.), well within the 50V
max. supply voltage the IC's are rated for. Both IC's are properly
heatsinked, though they seem to run quite hot - I assumed this was just
normal. I've also gone through the convergence board and power supply
looking for caps up in ESR, but found none.
The replacement IC's were supposed to be OEM, but I have to wonder just
how compatible they really are. It's the only explanation I can think
of.
I'm tired of wasting time and money on this piece of junk.
Unless I can be certain any further replacement parts will work, I'm
going to scrap it and take my losses, which would be close to $300 as
of right now. I will also vow to never gamble on a Samsung again -
they're nothing but trouble.
Any advice would be appreciated

Usually these problems are due to the static centering rings on one or
more of the CRTs being misadjusted and the convergence IC has to put out
a steady DC component to correct it. If you scope the outputs from the
convergence IC and see both positive and negative current swings into
the convergence magnets, everything is OK. If not, you need to adjust
the centering magnet(s) on the appropriate tube(s) and then re-converge
the set.

David

Certain Samsung models were pretty popular for this. I take it by your
knowledge that you've worked on a few.



--
Live Fast, Die Young and Leave a Pretty Corpse