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karoshi

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Hi there. I've recapped one of my New Net City Toshiba PF D29C051 in an effort to improve minor geometry issues, however, I seem to have damaged or broken something. I'm hoping some of your guidance can help me narrow down the culprit.

Post recap, the picture was bouncing around like crazy, until I left it on for about 45 seconds, when the picture went black with a very faint, tiny white line at the top of the display. It's sending power to the yoke and it doesn't appear that I shorted the high voltage.

Here's a video of the same signal being sent to two machines, after the cap. Yikes.
https://drive.google.com/file/d/1KZaqdTGcWxvviAG9NSfAKmeBuP-Wi4-V/view?usp=sharing

Here's a video of the monitor powering on and a brief inspection of the cables attached, while I looked for any other pots that might help me adjust the sync issues.
https://drive.google.com/file/d/10wKvXYHUqh0i9ITYFB0X4mzpu2trrKQZ/view?usp=sharing

Attached is a photo of what it looks like now.

The only obvious error I made, was I initially seated the monitor-service/calibration cable into the wrong port. After the screen stopped displaying a picture, I corrected the cable placement, but I no longer got any picture on screen at all.

Some notes:

- I bought my caps at a local electronics shop, and the larger ones I got online from Mouser. I made sure to take care with polarity, voltage, and uF.
- I did not specifically buy a "filter cap" when I got the 1000uf 250v cap. Could this be an issue?
- I did not replace the 'non-polarized' caps on the neck board. There's 3 of them, they are 250v at 1uF, and I couldn't find those anywhere, so I just skipped them.

- There was one location on the chassis which had a screen-misprint, in which the positive/negative silkscreen was flipped, different on the top of the board and the underside. I matched the original capacitor orientation.
- No obvious leaking or cold/cracked solder on the PCB.
- I did use an air compressor to clean out the dust around the back of the monitor and yoke. Could I have damaged something for a 70 psi short burst of air?


Before I take this to P&L for official repair, Ive considered removing the largest caps, and re-solder in the original filter caps. I would love to hear any other ideas of why I'm getting power, but no picture. Could I have shorted something?
 

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Tonight, I took a closer look at the board after some advice from another Arcade monitor master, and I discovered I used a "non polarize" BP cap, accidentally, near the vertical circuit which caused vertical collapse.

I immediately replaced it with a standard polarized cap. When I replaced the chassis, now I'm getting no picture, not even the white line.

Could I have shorted my HV output? How is this diagnosed? I couldn't find any knowledge here or on the FB groups about repairing HV output or replacing flybacks. How is this repaired if it is the culprit?
 
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I recapped the entire board with a fresh kit from Arcade Parts & Repair, and this completely solved my issue. I did not replace the large filter caps I did on the first recap.

There was either 1) something wrong with the caps or maybe 1 of the caps from the electronics store

2) not clean enough soldering work by me on the first pass, or something otherwise not making good contact.

3) something was installed incorrectly originally, which was corrected on my second recap.
 
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