Donkey Kong Jr Graphics Glitches - Help needed

[lesoleil70]

Hi All,

My DKJR had graphics glitches from the start, now is the time to get fixing it.

If any of you know why I have a blue Mario, and why Kong looks odd, please post me some pointers.

I've already reseated every chip I can, I went from vanishing sprites to blue mario...so it's an improvement, at lease ti can play it now, but it's not right..

I know next steps are voltages, and to be honest the power supply in there is so rusty it might just be a no brainer and I should just rip that sucker out, but I thought I'd post this anyway, you just might know this board and can say hey it's 3E from just seeing a vid.

Enjoy.

http://youtu.be/9cgy0wD_7do

[iankellogg]

I think you have a bad eprom. Which one, im not sure off the top of my head. But it will be whichever one has the moving sprites in it.

[John's Arcade]

Hi All,

My DKJR had graphics glitches from the start, now is the time to get fixing it.

If any of you know why I have a blue Mario, and why Kong looks odd, please post me some pointers.

I've already reseated every chip I can, I went from vanishing sprites to blue mario...so it's an improvement, at lease ti can play it now, but it's not right..

I know next steps are voltages, and to be honest the power supply in there is so rusty it might just be a no brainer and I should just rip that sucker out, but I thought I'd post this anyway, you just might know this board and can say hey it's 3E from just seeing a vid.

Enjoy.

http://youtu.be/9cgy0wD_7do

Check this out:

http://www.brasington.org/arcade/tech/dkj/

[iankellogg]

on closer inspection. the eproms look okay, but I think something is messed up on the color proms.

[lesoleil70]

THANK YOU !

All sorted.

Firstly, my -5v was all to cock, ripped out the power supply and put in a new one. That cured the horrible hum from the speaker, but not the graphics.

On the two board stack were smaller chips that could be reseated. Originally I just did the larger eproms and overlooked these,mistake!.

Anyway, these three smaller chips were reseated, and one of them had two bent pins.  I should really name them but I've just put the game back against the wall.

Straightened the pins out oh so very gently, my god they are fragile..., reseated these ones very very carefully.

Job's a good'un

Here's the result.  http://youtu.be/mAFRLqebZUA

Thanks a lot guys, might seem like basic stuff to you both, but for me this was new territory.

It was fun, especially since it worked.

Thank you.