PPUdigitizer glitching after 5 minutes of play

[Mike7599]

Hello,

I recently received the ppudigitizer from you and just installed it into my nes. Unfortunately the graphics start glitching after the system warms up. On a cold start up everything looks amazing. But after about five to ten minutes of play the graphics start getting corrupted and glitchy. I suspected bad capacitors so I recapped the nes and at the same time I reflowed all the solder joints to the ppudigitizer. Still no good. I originally hooked up to the RF jack. I then disconnected that and wired a shielded rca cable direct to the ppudigitizer but it didn’t seem to make a difference. I also hooked direct up to my CRT with component inputs and confirmed the graphic corruption was present there also. It’s very odd. Like I said, at first cold power up everything is great. Amazing picture but then the corruption starts and progressively gets worse. I will link a video I made showing it. (Just note the video from my test bench with a tink5x but I’m using the new 6x upstairs for the luma code). Also I should mention I soldered all 40 pins. Not sure if that would make a difference? Lastly I have tested and confirmed no issue outputting from composite at all. Any ideas? Thanks for your time!

https://youtu.be/OBm4FiOf-ks?is=teUQTmiUsrwkKv3Y

[c0pperdragon]

I am not completely sure what the exact problem is, but some other users also reported a similar issue. I suspect the clock input circuitry to the PPUdigitizer is not always receiving the clock properly. As this now seems to also be related to the operating temperature, this looks even more plausible.
Do you happen to have an oscilloscope to measure the clock input on pin 18 of the PPU/PPUdigitizer? Maybe I could spot something and come up with some idea on how to improve the matter.

[Mike7599]

Thanks for getting back to me. To me it appears the ppudigitizer starts overheating and causes the graphics to glitch. As a test I hooked up a fan. So far I’ve played over 1/2 hour with no glitching. I’m going to borrow an oscilloscope from my friend to get those readings (if you still want them). But I’m pretty convinced it’s the chip getting hot. Would you recommend putting a heat sync on top of the center chip to help?