need help with visual glitch on Arcade

[leejunfan777]

Started having visual glitch on a run
i suppose i need to "re-seat" a certain chip

can anyone help me with this ?
here is the twitch highlight & a separate video i made afterwards

thank you

https://www.twitch.tv/leejunfan777/v/71814892
https://youtu.be/QVZjn-8shpo

[YesAffinity]

dude, that's custom!  I think that makes your cab worth more. 

Sorry, tho, I don't have any useful information to help you solve the issue.

[tilt]

Ah, this is Vince Lemay's old cab right?  He had graphical glitches on and off with his cab throughout his time going for scores.  Eventually, the problems corrected themselves, but I seem to recall the 'relapse' of the glitches.  Anyhow, you can try reseating the roms but I suspect the issue will not go away that easy.

[Scoundrl]

I'd bet its low +5v on coming from your power suppy. Adjusting this is not super hard but it is a bit of a pain in the ass and does take a meter and some balls to adjust the pot with the game on and the power supply split into two pieces. Probably not a job for somone who would need help reseating chips, its a few orders of magnitude more involved and technical.

[Xermon54]

Ah, this is Vince Lemay's old cab right?  He had graphical glitches on and off with his cab throughout his time going for scores.  Eventually, the problems corrected themselves, but I seem to recall the 'relapse' of the glitches.  Anyhow, you can try reseating the roms but I suspect the issue will not go away that easy.

Yeah I had graphic problems for a long time but I had never tried to fix it before (I didn't really give a sh*t about the graphics lol). Before selling my machine to Vincent Côté, I reseat all the rom set and the machine was working perfectly afterward. It just sucks to see the machine having graphic issues again though.

But don't worry guys, the machine is still on warranty, if it cost something to repair it I'll definitely help him, I won't be a dick 

[jammyyy]

hay Ken when i got that that pcb as is the it had graphic problems, i just re seated all ROM`s and was fine but there was one 7a or 7b i think on the video side that needed resetting again later on. was not a big deal for me ti fix if it acted up again, the pins are tarnish and could use a good cleaning or just re seated it , makes a good connection , ,,, have fun newbie your learning

[jammyyy]

http://www.brasington.org/arcade/tech/dk/  have look at this link . this guy corrupted each ROM to see what the game would look like ,,, im all most 100% its one Moving Objects (sprites) in the 7`s that need resetting/clean up  

[Sock Master]

There are about a hundred chips on a DK PCB set, and any one defective chip could cause some sort of problem.

There are some descriptions of hardware problems and their solutions here:
https://www.mikesarcade.com/arcade/repairs/dkong.html

and here also, as DKjr is almost exactly the same hardware:
https://www.mikesarcade.com/arcade/repairs/dkjr.html

But none of those sound exactly like your issue.  A couple do sound similar and might be used as a starting point for tracking down the problem, but essentially this would take some investigative troubleshooting.

If the board does power up fine and the graphical glitches only appear after it warms up, a can of Freeze-it could help pinpoint the culprit.

[leejunfan777]

the machine power up fine, & the glitches are there from the begining, they dont appear after a while

[Sock Master]

Probably not a thermal issue then.   It sounds like it might be a marginal chip, or simply a loose connection somewhere.

Have you tried whacking the PCB?  A sharp tap to the board (safer while power is off).   If anything changes for better or worse, and further taps make it vary randomly... it's a good sign that it's just a loose connection.

Try...
-Unplugging and re-plugging the wide ribbon cables between the two boards.
-Pulling out socketed chips, carefully scraping the 35 years of oxidization off the pins and putting them back in their sockets one by one, including the small PROM chips (but DO NOT PLUG THEM BACK IN BACKWARDS).

[Scoundrl]

Voltage up .15v and they will be gone. Its not super well documented but it is a know issue (It was actually part of the old stupid 'Only an original Nintendo power supply can be used for submissions).

[jammyyy]

i dont know if you know this John, i built this machine and the was my pcb , i gave it to Vinc so im pretty sure its just the rom in 7,s that was problem i had    "the glitches are there from the begining, they dont appear after a while" sounds about right the rom is walking when heats up it expands and when it cools down contract`s ,,, i had theses video privet because there embarrassing to me but you can look at them now to see i put a lot effort in to making sure vinc hook up right https://www.youtube.com/watch?v=_q-zemmKTSc

https://www.youtube.com/watch?v=dFLS2pLaBo0

https://www.youtube.com/watch?v=nN0IeB5gLIs

[leejunfan777]

after investigating a bit, im pretty shure the power supply is related to the issue
i left tha machine unplugeg for a while, & undusted everything related to the PowerSupply
& when i powered it back on the visual glitches werent there anymore
but unfortunately, they reappeared after 5min of gameplay

[Jonesy]

As John said above. It sounds like a chip may well be failing when it gets some heat into it.

Buying a can of freeze it and spray each chip until the glitch returns to normal. Replace that chip sir and you should be good to go?

It's a tricky one.

[leejunfan777]

i tried reseating every rom chip
the problem seemed to go away but reappears after a certain time
if i leave the cab unplugged for a while, when i restart it there's no glitch up until 2-3min of play
but if starts again after that