Odd video issue after recap

[ProNEC]

My Turbo Express unit did not have working sound, but the video was fine. I ordered a cap kit and recapped it and now the sound is working flawlessly, but the video output is now a bit messed up.

Sample video: https://www.dropbox.com/s/18rzz2u7410u2ns/VID_20191230_160825.mp4?dl=0

If the above link/video did not work, the issue is there are odd shadows casting to the right off of sprites and the left edge of the screen. Areas are a bit dark, but no real rhyme or reason as to where or why. It just looks overall odd and not right, colors off a bit etc.

I tested all the capacitors and their capacitance is good. Also verified they were all in the correct location and with proper polarity. I did replace the two caps that are for the jailbar fix at C715 and C709 as well (which may not have been necessary), but was unable to put them back to stock for a test, as I lost one. That may or may not have anything to do with it anyway.

Not sure where else to look. I did inspect the entire board for oddities, but nothing really coming up. I cleaned a bunch of areas up more, especially around the 6260 chip, but I am unable to get the video back properly. Where should I look next?

Thank you.

[Keith Courage]

No need to have those extra caps in there for the jail bar fix. That's really just for RGB out for TVs.

Anyways, look really hard around the Hu6260 chip. A small piece of solder could have gotten in there bridging some pins.

Also, look at this section to make sure none of the connections are gooped up with old cap leakage. Circled in red



 

[ProNEC]

Thank you for the reply. I have double checked again real well around the 6260 chip (and every other chip) and everything seems fine there. Also cleaned up the area you highlighted, albeit it looked clean as can be already. Still same video issue... I even put back both of the stock caps (I found the one I had originally lost) and the video issue still remains...

Could I have left the heat on a pad too long near a chip and fried something irreversible in a chip or other transistor?

Thank you.

[Keith Courage]

Usually the areas I mentioned are the problem. If not then the HU6260 chip might be damaged.

This could be a good candidate for a screen upgrade though. Never hurts to try the composite video mod to a TV to see if the picture is correct.

[ProNEC]

Yes, some sort of video mod is of course where I expected to go next to validate the video operation is functional outside of the internal screen. Not sure how the screen would've potentially been damaged during the recap, but perhaps the ribbon cable is having an issue, which I will check when I open up the display portion of the unit. Thank you for pointing me in the right direction.

[Keith Courage]

Here is the composite circuit.