25" GE stereo tv model:25GT522JX2,chassis:CTC177AF3,year:April
1995.One day suddenly the picture became purple/red (no green),I
assume that there was a loud pop or snap noise but the customer does
not recall.
Upon troubleshooting I discovered that the green drive signal was
absent from the crt all the way back to U1001V=T-chip=tv color
processor IC=TV jungle IC=LA7610=$20 CDN=RCA # 215524.To be sure it
was not the crt I swaped the red and green wires on the crt board and
the picture became green so that ruled out the crt,furthermore the dc
drive signals going back to the green ouput pin (I believe pin 36) of
U1001V were also lower in comparison to red & blue so I assume that
U1001V=LA7610 is defective but from reading many posts in the past the
CRT's green gun maybe intermittently arcing causing the IC to fail.
I have read many posts about making home made modifications such as
installing a diode to the 200V line,another is to install a 5.1v zener
diode to the green output pin of U1001V.I don't have a crt
tester/checker/restorer but I have always used this crt zapping
technique which has worked about 70% of the time:

http://www.anatekcorp.com/ttg/tiptri...20CRT%20Shorts

there are also other techniques which I have not tried at:

http://www.anatekcorp.com/ttg/tiptrick.htm#HK%20shorts%20in%20CRT's
http://www.anatekcorp.com/ttg/tiptri...CRT%20Restorer
http://www.anatekcorp.com/ttg/tiptri...k%20CRT%20Test

but I have never tried the first technique (that I commonly use on
other makes) on a RCA/GE/Thomson tv yet with those sensitive EEPROMS
and T-chips.Also T4401=flyback # 2G25026-B2H=2G25026-82H=RCA #
215539=HR Diemen # HR-8555=Global Electronics # FLY-382=$20 CDN is
making a loud squeal noise and from time to time the picture is dark
so I am pretty sure I have to replace it as well as I have replaced
these flybacks before for the same symptom.
Note:the customer won this tv in a raffle/lottery draw at the Halifax
Cost Co (Price Club):

http://www.costco.ca

so he doesn't want to spend to much money on it.Conclusion:is there a
simple technique to fixing the CRT? is there a simple reliable
modification that I can make to the crt board or around the LA7610 to
make the new one last? or should I call the customer and tell him the
tv is junk?.Thanks in advance.

For free service manual downloads,repair tips and mo

http://www.schematicsforfree.mattsoft.net/

Sidney

Dartmouth,Nova Scotia
Canada

Iv' changed a couple of the LA7610 IC's,
& they have never come back! Tube may
not be arcing! Rono.

On Fri, 1 Apr 2005 18:43:34 -0330, "Rono" wrote:

Iv' changed a couple of the LA7610 IC's,
& they have never come back! Tube may
not be arcing! Rono.



Not to be impertinent, but perhaps they are being taken somewhere else
for susequent follow-up care? I have seen many jungle IC's fail in
this way due to the CRT arcing, and one technique to prevent it is to
clamp the CRT drive outputs.

Tom