Hi Charles,

Lowering the brightness (very low) allows the TV to stay on. I suspect
the problem relates to beam current sensing circuit or TDA9577H (no info).
I notice that on pin 55 of TDA9577H, the voltage changed apx. 2 tenths of
a volt between pattern generator and TV signal (before lowering brightness).

Note: No beam current (if you remove CRT pcb) will also cause a shut
down.
Brad


On Wed, 10 Jan 2007 15:49:20 -0500, in sci.electronics.repair you wrote:


"Brad" wrote in message
...
Hi Charles,

Correction: IC7200 is actually a TDA9577H (Sams listed it as "TDA9588H")

I thought the beam current might be causing a shut down. I have Sams
Photofact 4968 for this model TV, but it leaves out a lot of information.
No pin out info on the jungle IC 7200, TDA9588H/N1/1133, and I couldn't
find it on the web. I assumed pin 54 may control shut down by excessive
beam current so I opened that circuit and used a 100K, then 200K to
ground
resistor which set the voltage close to what was on the schematic, but the
TV still shuts down. Another pin 55 on that IC relates to "BCI", but I
didn't experiment with that circuit. I have used a lot of time trying to
fix this mystery problem.

Sorry Brad ... I tried a Google for the part no. but could not find a data
sheet out there. If you run the brightness all the way down, does it still
shut down?

BCI is intriguing ... beam current ... ?

Good luck!