Problems with 11AK19P E-W control

[FrankvanSteene]

Hi there!

Yet another topic about E-W control on a 11AK19P chassis. Unfortunately the other topics all couldn't help me solve the problem.
Ok. I'm having some problems with my Schneider Cinema 3201 television (11AK19P chassis).

[b]The problems were: [/b]
1) 6 Lines (2 red, 2 green and 2 blue lines),
2) Sometimes the picture size reduced to only half it's original size.
3) The tv has got a problem in the E-W correction circuitry (excessive width, pin cushion).
4) When tv's is switched on, sound volume always reduced to 0.

I managed to fix the first problem by repairing the severely damaged PCB around the vertical deflection IC.
The second problem was fixed by resoldering the entire line output stage but the third problem, the malfunctioning of the E-W correction circuitry still needs to be taken care of.

[b]I already tried these things to fix the E-W correction:[/b]
Replaced the s/c Q603 (PHF 9NQ20T).
Replaced IC401 (TDA8843)
Replaced R629 (had a value of only 2R2 but according to the service manual it should have a value of 27R with a 16:9, 32" picture tube).
Replaced C630 (470n 250V), C621, C620, C613, C626, C617 (470n 250V) and C618 even though they all measured ok, just to be sure.
Replaced D611, D612 (also measured ok, replaced them just to be sure).
L602, L603 and L604 are all ok.
Checked connection between the different components and didn't find a crack in the PCB.

I measure 2.2 Volts AC at the drain of Q603 (PHF 9NQ20T), only 0.2V at the gate.

When I connect my osciloscope to pin 45 of IC401 (TDA8843) I measure a very weak sinus-like signal. The amplitude of this signal increases or decreases when trying to increase/decrease the E-W width so I asume IC401 is ok. Supply voltages for IC401 are all ok, ref voltage on pin 52 for E-W output stage also ok.

When I take out C614 in order to completely disconnect the E-W windings of the FBT (HR8402) from the rest of the E-W correction circuit, I measure a voltage of approximately 8 Volts on pin 4 of the FBT. The voltage is pulsative with an interval between each pulse of approximately half a second.

Hopefully this doesn't mean my FBT is ready for a replacement?

Haven't tried anything yet to fix the fourth problem because the E-W problem is more important to me.

Hopefully anyone of you can help.

Many thanks in advance,
Frank