K7000 447 Sync Issue

Fluxar

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Specs: K7000 447 19" Wells Gardner Standard Resolution Chassis with a 456 Neck Board
Issue: What appears to be a horizontal sync problem

Back Story: This chassis was dead in the beginning and came out of a Akari III. Removed the chassis and went through standard testing procedures. Found the HOT to be bad, and flyback cracked. Went ahead and capped it, new flyback, and HOT, I think I may have had a bad diode (can't remember). All in all, fired it up on the bench with the TPG, all worked perfect. Took it back to the arcade and installed and it looked like the images below..... Tried to adjust everything out and still same result. Removed the chassis brought it back to the bench and same result with my test CRT.

What I did after: Swapped the Horizontal Hold and Pos Pots. Ran through all standard tests, reflowed header pins again and various other points. Still exact same result. You will see two images, one blue and one red. The red image is with both of the sync pins connected (9 and 10), and the blue is just one connected (10). I tested a couple other 447 chassis with the TPG in the 9 and 10 and the 10 config and they work perfect.

Maybe? IC issue or bad flyback? If any other details are needed let me know. I have loaded a few additional images as it may be asked of me. I submit to the gurus!

Thanks in advance,

Kynan
 

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K7000 is horizontal negative sync. So in your pics, I believe it's the white wire on the TPG (other yellow wire is marked -v)


In your connection pics, you have either the yellow wire connected only:
1733939668486.png



Or both horizontal and vertical at the same time:

1733939713923.png

Try turning the header 90 degrees so that only the white wire is connected to pin 10.
 
Last edited:
Just plug up the white one on pin 10. The yellow can be on pin 9. Just make sure they both lineup correctly from the source (TPG) and the chassis.
 
Did you rework the solder side of the board? K7000s are notorious for having bad/cold solder joints on many if not all of the high wattage resistors and many other components in the power/HV/HOT/Deflection portion of the boards. I'm talking remove old solder, scuff up the pads with fiberglass pencil, and reflow. Also the header pins that you're connecting your tests signals to.

I never put a K7000 back into service without a through rework of the solder side.
 
Did you rework the solder side of the board? K7000s are notorious for having bad/cold solder joints on many if not all of the high wattage resistors and many other components in the power/HV/HOT/Deflection portion of the boards. I'm talking remove old solder, scuff up the pads with fiberglass pencil, and reflow. Also the header pins that you're connecting your tests signals to.

I never put a K7000 back into service without a through rework of the solder side.
if only the professional monitor fixing companies/distributors adhered to this strategy without charging people stupid money
 
if only the professional monitor fixing companies/distributors adhered to this strategy without charging people stupid money
I agree. When I rebuild/cap a monitor, reworking the problem areas is included in the price, along with testing and running the monitor on an actual compatible tube for several hours - longer if a new flyback is involved. There's nothing worse than getting a monitor back immediately after it's been "fixed" or having it not work because of a solder joint cracked in shipping.
 
It looks like a video ground problem, make sure all the vid ground is connected and good solder on input pins.
 
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