RETRACE LINES , CRT WEAK ? RCA 27 "

[Bentech2001]

Hi , I have a RCA Model F26103CG (chassis ctc149 b , i think) that has
retraces lines.

When increas/decrease the screen control , voltage at the screen pin on the
CRT socket is moving ( ~200 to 500 volts) but I did not put the control to
the min or max.

On a proper brithness of the screen , I have 400 volts but retrace lines.On
the cathode of the colors , I have ~ 118-132 volts.

Can it be the CRT ?

I also change a 47 uF/250v (C703K) that was bad near the flyback but
samething after
changing it...


Any idea ?

 

[Lance Dyer]

Q2901? luminance amp

 

[Jerry G.]

I have not worked on your model, but can give advice in general.

If there are no blanking defects in the set, and the CRT emission is still
usable, decrease the G2 or screen bias to not have retrace lines. Now look
for the black bias controls, or use the service set-up if necessary.
Increase the black biases for each of the CRT guns. Take care to maintain
the proper grey scaling colour balance.

If you lack range, to get things right, and the power supply, and high
voltage is working properly, then the CRT emissions must be low.

--

Jerry G. GLG Technologies GLG
==========================


Hi , I have a RCA Model F26103CG (chassis ctc149 b , i think) that has
retraces lines.

When increas/decrease the screen control , voltage at the screen pin on the
CRT socket is moving ( ~200 to 500 volts) but I did not put the control to
the min or max.

On a proper brithness of the screen , I have 400 volts but retrace lines.On
the cathode of the colors , I have ~ 118-132 volts.

Can it be the CRT ?

I also change a 47 uF/250v (C703K) that was bad near the flyback but
samething after
changing it...


Any idea ?

 

[Bentech2001]

Does anybody having this part of this schematic ?

Thanks;...