Motorola TS-4J

[Electronic M]

May want to scope the sync separator...if it is letting video or noise through that could be freaking out the sweep.

[Zsuttle]

Originally Posted by timmy

More pics.. You said the pic is on the dark side and Alittle jittery, have you checked the contrast/ agc adjustment on the front right. There may be 2 caps off that pot, maybe check them.

It could be, the when the contrast is all of the way up, the picture goes out of control. I'll replace the three that are there. EDIT: I was able to successfully get the picture back to normal by replacing the three capacitors around the contrast control. However, the slight shudder is still there along with the uncontrollableness created by turning the contrast or brightness to full.

Originally Posted by Electronic M

May want to scope the sync separator...if it is letting video or noise through that could be freaking out the sweep.

Not entirely sure what to look for, however, here's the output of the plate on the sync. Hopefully that helps.

20190220_153323[1].jpg


I've also purchased a TV analyst for troubleshooting, seems like a useful tool. WOn't be here for another week

[Electronic M]

Originally Posted by Zsuttle

It could be, the when the contrast is all of the way up, the picture goes out of control. I'll replace the three that are there. EDIT: I was able to successfully get the picture back to normal by replacing the three capacitors around the contrast control. However, the slight shudder is still there along with the uncontrollableness created by turning the contrast or brightness to full.



Not entirely sure what to look for, however, here's the output of the plate on the sync. Hopefully that helps.

Attachment 198290


I've also purchased a TV analyst for troubleshooting, seems like a useful tool. WOn't be here for another week

That waveform looks pretty messy and weak...See if sams has a waveform and compare. If your sync pulses are messy you will trigger retrace mid line and other troublesome things like that.

[Zsuttle]

Originally Posted by Electronic M

That waveform looks pretty messy and weak...See if sams has a waveform and compare. If your sync pulses are messy you will trigger retrace mid line and other troublesome things like that.

http://www.earlytelevision.org/pdf/m..._rider_tv1.pdf

ETF has the riders which has the waveforms in it on page 30. It's interesting to see that there's a 60hz signal on the sync output, that might explain the jittering. How much of a waveform should I realistically be getting on the power supply? I would have thought that the filter caps being as big as they are would have taken care of it.

[Electronic M]

Originally Posted by Zsuttle

http://www.earlytelevision.org/pdf/m..._rider_tv1.pdf

ETF has the riders which has the waveforms in it on page 30. It's interesting to see that there's a 60hz signal on the sync output, that might explain the jittering.

There should be 60Hz in the synch output. Vertical sweep IS 60Hz* and it needs 60Hz sync pulses.

*Granted color changed it to 59.9Hz, but rounding is a thing.

[koviatt]

Originally Posted by Zsuttle

It could be, the when the contrast is all of the way up, the picture goes out of control. I'll replace the three that are there. EDIT: I was able to successfully get the picture back to normal by replacing the three capacitors around the contrast control. However, the slight shudder is still there along with the uncontrollableness created by turning the contrast or brightness to full.



Not entirely sure what to look for, however, here's the output of the plate on the sync. Hopefully that helps.

Attachment 198290


I've also purchased a TV analyst for troubleshooting, seems like a useful tool. WOn't be here for another week

Does this screenshot of the manual help? I had the same problem with my set and discovered that I replaced the cap that parallels the primary side of that transformer with a higher value and it filtered out the horizontal sync pulse to almost nothing.