Any ideas on vert. Clipping? On Sony micro TV?
 

I’ve had this for a while, same issue before and after replacing the electrolytics. Vertical seams to fold over itself, not exactly sure what this symptom is called, but does anybody have any idea of what is going on here? Playing with the linerality, height, center etc won’t Remedy the problem, There is definitely something weird going on here.

Most likely that set will need everything electrolytic totally recapped. Also if it's like the 5-303W the adjustment pots were carbon and not that reliable. Looks like a nice project.

Hey thanks, yeah I did change the electrolytics, and you are correct, the adjustment pots were flakey but seem to by under control after cleaning.

At this point, I am unclear as to what could cause these symptoms. Possibly low power to the vert. Circuit? Or a dying transistor if that is even possible?

It's hard to tell from a still picture - can you determine if the vertical is merely shrunk, or is it running at a much higher rate than 60 Hz? If it's a much higher rate, there is some component that is way off value.

Hello,
The best way to describe it is that the image seems folded over itself from the top part, and won’t really expand to the entire length of the screen with the adjustments.

Since the caps are changed, check for out of tolerance resistors in the vertical, and if that doesn't work check voltages and transistors.

I have an unrestored original example of that set and mine barely syncs at one end of the hold control...at the other it starts to fold over.

Thanks for the tip. I’m attaching some more pictures. First is another TV that’s working OK so you have an idea of what it should look like, then it’s the Sony with the vertical hold stable in a center position, then the only other option where it is stable is all the way turned to the left with the picture also repeat it self. Do these Help give any more ideas?

It is possible the vertical is running at twice or half frequency...It is hard to conclusively tell with most program content. I had a 1953 Zenith that was runing at a multiple of the correct frequency to confirm the problem I created a grid of numbered lines to use as a test pattern....I had to use paper and a camera then, but it would probably be easy to do with modern computer systems.

It would be easy to tell if the frequency is incorrect with an oscilloscope, but I suppose if you had one you would already be trying it.

I have an oscilloscope, i really don't know what frequency i would be looking for and where to sniff for it. would you give me some pointers? thanks

The entire vertical circuit is supposed to run at 59.94Hz and output a sawtooth waveform to the yoke...The waveform may not be a saw tooth everywhere in the circuit, but it SHOULD be the same frequency everywhere in the vertical circuit.

OK thank you very much, I will check after work tonight!

I have an 8-inch Sony from the same era that's got the same problem, only quite a bit worse (it's off the bottom of the screen with scan lines about 1/2 inch apart). It's on frequency, and you can sort-of see the vertical roll and lock when you turn the vhold control.

I picked it up at a junk store for cheap, and figured a recap would take care of it. Imagine my surprise to discover that it had already been completely recapped in the power supply and vertical section. Voltages and waveforms are all as they should be, transistors and diodes check good, transformers ohm out correctly, but...the vertical is still messed up.

I guess someone took it to the junk store when they couldn't fix it.

Welp I have good news, but don’t have that warm fuzzy feeling of closure. I started probing around With my scope probe on the board outputs and then in the location that is pictured and pointed to with the chopstick. Low and behold in the last location the picture started jumping around and snapped up to almost a full screen. Now I was able to adjust the array of vertical controls to gets a nice full screen linear image. Quite possibly with how that inductor was positioned, it could have been shorted this whole time. I probed around with a chopstick and everything seems stable, it is not reverting back to its previous behavior. A picture of the waveform at that location while it was still having the issue as described previously is attached as well. I probed around with a chopstick and everything seems stable, it is not reverting back to its previous behavior. A picture of the waveform at that location while it was still having the issue as described previously is attached as well. I am happy with the progress, this unit was shelves for 10 years and always on the back of my mind.

Could be something shorted, but I'm thinking possible bad solder joints. Maybe a little touch up with a low power soldering iron?