Starglider01

Video updated with the final results!: Timestamps of updates: 16:18 - Trying ferrite cores for the interference 24:48 - Addressed and resolved screen flickering when pressing fire! Thanks again everyone!

Good news is it doesn't happen at all on the big screen which is the VCS's final home. Updated video incoming! Ferrite cores also make an appearance, solving the interference. I am [emoji817]% done! [emoji3060]

Well it doesn't seem to happen on other games like Donkey Kong so I'm guessing it's to do with that scanline technique ESB uses that was alluded to above, in combination with the composite mod.

I don't think I have that one. towards the end of the video I realized we could hold down fire. it is the very act of the fire button joystick signal traveling to the computer (or from it if it's bringing it to ground) that causes it. Holding down fire stops it. Perhaps a momentary voltage dropout or increase. But I have a new voltage regulator on there. for some reason it doesn't bother me so much. at first I thought it was a clever effect by the game to add more drama! At the very worst it is charming to me, keeping in mind that this is nearly five decades old... ¯\_(ツ)_/¯

CB?

Well, I've seen other reports of that exact thing online and they suggest the 4050 chip or the caps by the joystick port. I replaced one cap on each side with the static mod as you saw. Not sure I'm up for replacing all the other ceramic caps just yet lol...

Private draft of the resulting video. Thanks for your help guys!

I just had a breakthrough! I had tried 5 outlets in different rooms and opposite ends of the house. I tried a 6th outlet, with an extension cable, and suddenly the ripple is gone!! The picture is as close to perfect as I could've hoped! So there was something in the electrical circuits bothering the old hardware of the VCS. ¯\_(ツ)_/¯ This is as close to a solution as I could hope so I'm happy to say... drum roll please... problem solved! Thank you all so much for your help.

Hi guys, aside from the 60 Hz interference I've been seeing, I've noticed the whole screen "flashes" or flickers (like a half-second loss of vertical hold) briefly when pressing fire on either joystick. I've tried swapping out the 4050 chip in this heavy sixer, and have also done the field service manual static fix on the joystick port caps, adding a diode across a new cap. No change. Any ideas? Thanks!

Same problems.

Well I've put everything back together and this is the best I can get it. unfortunately the interference looks worse on a better TV. Video: https://photos.app.goo.gl/2J1gqPZgBreE59JG6 But this gives you a very good look at the interference pattern in case that helps some more. Interestingly if I only plugged the left audio in the interference was 10 times worse. Plugging both audio jacks in made things much better, which is what you see. I'm willing to forgive this as it is nearly half a century old, but if you have any other ideas to let me know. Thank you all for your help.

L201 was out a while ago, then back in, and is now back out... No change. I don't know that I still have R210 to reinstall. Do we think that will stop the ripple or not likely? Thanks guys.

I have and it didn't help, but I haven't tried it since the latest improvements. Will try again tomorrow.

I have tried 4 now. So no lol.

Okay. Just that RF ripple moving up the screen to worry about then...

Sure, that works. Is that normal then?

Tried but no improvements noted. Thanks anyway.

I have now replaced those wires completely and soldered new ones to the SMD board directly. Moving the wires no longer affects the image quality. So I'm going to say there was an issue in the wires. However, I still get the interference on the picture. I just can't change it now. Overall I'd say it's better though! Here's the latest example: https://photos.app.goo.gl/RJGysPAREtMJ2Lsz8 To me, at the end when I reset the VCS so the coloured background stops changing, it isn't terrible for a 44 year old machine. Should I really be striving for greater heights? If so, what's next? All I can think of is resocketing the TIA etc. Worth the risk?

I generally have it on 2-3, higher for the big switch pads. I will turn it down a little on your recommendation for these older pads. My wiggling is 0.5mm off the board - its just general good practice as you say :-) The regulator pads were lost due to the heat sink not being soldered to the ground plane from the factory, so unfortunately when I put it down and some weight was exerted on it, it pushed the VR pins through and lifted the traces. That repair seems solid now though FWIW and touching it makes no difference to the picture. The only things I haven't tried that I can think of are: 1. Replacing the mod's wires completely (complex/risky due to tiny SMD PCB) 2. Installing new sockets for the 3 chips

Yes, B&W had the same interference according to my footage. Other games are the same... Defender... Asteroids... Solder issues are possible. I've reflowed the 3 chips though I didn't install new sockets (they looked good). I've pushed and poked and prodded everything over the past weeks! The only changes to the picture are when lifting the entire board or playing with the composite mod wires. Reassembling the VCS into the RF shield doesn't help. I have tried 2 RIOTs, CPUs, and TIAs.

I haven't specifically desoldered/replaced those as I didn't want to damage any pads on the VCS, but I believe that the bypassing test I did ruled that out. However I will probably give it a go soon just to be sure. Pray for my pads!

1. All recent tests have been without a controller. With that DK test, moving anything would cause changes. That has stabilized a bit since I've been troubleshooting. But even now, just moving the mod's wires, or the VCS itself, causes the interference pattern to change/improve/worsen. 2. As above. Thanks.

Yup TIA was swapped... I've actually tried 2 TIAs. On some level I'm prepared to say this is 44 years old and entitled not to be perfect... But if you have any other ideas, I may never give up. Feel free!

Okay I have tried this. Short story: Same result. I went one step further and bypassed the composite mod completely, touching my makeshift cable composite directly to R216, and GND to R237 or the TIA GND. Although the colours were weird, I got a picture, but the same artifacts/interference. So I think we can safely say it's not the mod and is something with the VCS... (although I didn't desolder the cables going to the mod as the VCS pads are getting fragile, so it was technically still connected to the VCS albeit not to the TV.) I've now also tried 3 PSUs, but no improvement.

Thanks. Jack is brand new and Dupont untwist didn't help. Fingers crossed for the PSU!