Fada 899 - Videokarma.org TV - Video

stusnyder · #1 12-12-2011, 04:21 AM

Been working on this Fada model 899, restuffed all the e-cans, replaced some of the paper caps. Got no raster. Checked the tubes, tested good. I did the srewdriver trick at the cap of the damper tube, get a nice long arc. Could it be the doorknob cap? If so, how do you test it? What can be used in it's place?

tvdude1 · #2 12-12-2011, 06:22 AM

check ion trap

Don Lindsly · #3 12-12-2011, 10:09 AM

1. Make sure the high voltage rectifier is OK, likely a 1B3.
2. Check ion trap (beam bender) is in correct position.
3. Brightness control all the way up.

stusnyder · #4 12-12-2011, 12:18 PM

Quote:

Originally Posted by Don Lindsly

1. Make sure the high voltage rectifier is OK, likely a 1B3.
2. Check ion trap (beam bender) is in correct position.
3. Brightness control all the way up.

Did all 3, moved ion trap all over the place. The only thing I did not check yet is high voltage at the crt. I don't have a meter that can handle it.

Steve McVoy · #5 12-12-2011, 12:36 PM

You can eliminate circuitry that drives the CRT as a cause by shorting the cathode and control grid of the CRT together while you move the ion trap around.

Take the HV connector off the CRT and hold it near the chassis. You should get a nice healthy spark at least 1/2 inch long if your HV is good.

stusnyder · #6 12-12-2011, 02:21 PM

Quote:

Originally Posted by Steve McVoy

You can eliminate circuitry that drives the CRT as a cause by shorting the cathode and control grid of the CRT together while you move the ion trap around.

Take the HV connector off the CRT and hold it near the chassis. You should get a nice healthy spark at least 1/2 inch long if your HV is good.

Which pins? it's a 10bp4

Steve McVoy · #7 12-12-2011, 03:31 PM

The high voltage is the connector on the side of the tube. Cathode is pin 11 and the grid is pin 2.

stusnyder · #8 12-12-2011, 05:16 PM

Got the hv at the crt, seems weak to me, but at least the raster is back. Going to continue replacing paper caps and see where that goes.

stusnyder · #9 12-15-2011, 10:22 PM

Finished replacing all the paper caps last night, worked on it more tonight. Found 3 resistors that got pretty hot at one time, checked and they were showing low resistance, so I replaced them. Fired it up and the horizontal was out of sync. Got that adjusted up and after some tweaking got a pretty nice pic

. Hooked up the speaker and had nothing. Put in another audio output tube (6K6) in and had purple and sparks fly inside. Pulled it right away. Checked the voltage on the socket and had 250 volts on pin 5, suppose to have -9 volts

. Found a capacitor lead from pin 4 up against a resistor lead on pin 5. After separating them, plugged in the tube and had sound

.
Next up is cabinet work.

Reece · #10 12-16-2011, 05:36 AM

We need pix!

stusnyder · #11 12-16-2011, 09:24 AM

Quote:

Originally Posted by Reece

We need pix!

Here u go:

I have my small test crt in the rig right now. Also the tuner needs to be cleaned up, because I got some noise in the picture. But since I know it's do able I'll start on the cabinet next.