Donkey Kong problems

arch8ngel

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I picked up a cheap DK cabinet a few weeks ago, and finally got around to recapping the monitor (the screen had a non-functional v-hold, and a visible "fold-over").

Well, now that I've reassembled it...I have a few issues.

(1) It seems like even when I adjust the H-centering all the way to the bottom, the screen has the high score partially cut off, and there is a ton of blank space at the bottom of the screen.

(2) There are pink jail bars on the screen.

(3) Dialing the brightness all the way down isn't as "dark" a background as I would have expected.



Do I need to get my EPROMs reflashed? I noticed when I had the machine open, that the "windows" on the chips weren't covered, so I'm worried that I've allowed them to "rot".


Thanks for any tips.
 
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Sounds like your DK Board is still ok. Have you checked the POT on the brightness, and DId you just get the basic Cap kit? Id ask in the monitor section. but you may need the rest of the Caps for the Jail Bars??? In not sure though
 
Sounds like your DK Board is still ok. Have you checked the POT on the brightness, and DId you just get the basic Cap kit? Id ask in the monitor section. but you may need the rest of the Caps for the Jail Bars??? In not sure though

The cap kit I had contained 16 capacitors. I'm pretty sure it was whatever QuarterArcade carried that said it was a Sanyo 20EZ cap kit.

I'm knew to this, so how do I check the brightness pot? I've dialed the pot all over the place, and it gets brighter, but at the extreme low end the background is not black, at all. (though this could all be part of my pink jail bar issue).



MODs, can you move this to the monitor side, since that's probably where it belongs?
 
The cap kit I had contained 16 capacitors. I'm pretty sure it was whatever QuarterArcade carried that said it was a Sanyo 20EZ cap kit.

I'm knew to this, so how do I check the brightness pot? I've dialed the pot all over the place, and it gets brighter, but at the extreme low end the background is not black, at all. ?

It sounds like you POT may be ok but i would check the B+ next
 
Hopefully it's something simple like that.

I think there is a very good likelihood that I bumped/moved all kinds of stuff that I shouldn't have touched when I was getting the boards out of the machine to do the cap kit.
 
Thanks for the tip. The B+ Pot is definitely the next thing I'm going to mess with. I figure if I can get black to show up as true black, I'm moving in the right direction.

Then I'll see if I can hunt down my centering issue (I get the impression from the monitor manual, that it's possible to adjust the actual magnets that center the picture).

Then I'll finally tackle the jail bars...


ETA: also, my sound was disconnected when I got the machine...and I can't seem to get it to function at all.
 
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Thanks for the tip. The B+ Pot is definitely the next thing I'm going to mess with. I figure if I can get black to show up as true black, I'm moving in the right direction.

Then I'll see if I can hunt down my centering issue (I get the impression from the monitor manual, that it's possible to adjust the actual magnets that center the picture).

Then I'll finally tackle the jail bars...
B+ being incorrect (high or low) usually produces shut down, waviness or jittering. True black is obtained by using a combination of the brightness pot in the middle of the monitor chassis, the pot located on the board on the back of the monitor with all your pots lined up and the flyback. Your jail bars are most likely showing because your brightness is completely off the scale not because of any magnets. You really need to use the search engine as there is a plethora of Sanyo 20EZ material. You're dealing with a completely minor issue easily remedied by "ADJUSTING" the proper items. Same rule applies for your centering issue. Combination of pot on game PCB and pot on monitor chassis. The only need for adjusting your "magnets" is for converging purposes. Pictures are worth a million here.
 
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B+ being incorrect (high or low) usually produces shut down, waviness or jittering. True black is obtained by using a combination of the brightness pot in the middle of the monitor chassis, the pot located on the board on the back of the monitor with all your pots lined up and the flyback. Your jail bars are most likely showing because your brightness is completely off the scale not because of any magnets. You really need to use the search engine as there is a plethora of Sanyo 20EZ material. You're dealing with a completely minor issue easily remedied by "ADJUSTING" the proper items. Same rule applies for your centering issue. Combination of pot on game PCB and pot on monitor chassis. The only need for adjusting your "magnets" is for converging purposes. Pictures are worth a million here.


I appreciate that you're offering advice, but antagonizing my lack of searching isn't helpful, or necessary, thanks.

It's good to know that you think only adjustments are required.

This is my first arcade machine repair, ever, so excuse my ignorance to the plethora of things that can be adjusted.
 
I appreciate that you're offering advice, but antagonizing my lack of searching isn't helpful, or necessary, thanks.

It's good to know that you think only adjustments are required.

This is my first arcade machine repair, ever, so excuse my ignorance to the plethora of things that can be adjusted.

There was never any attempt to belittle you. We've all been there and still need help periodically. I simply made a few suggestions to help you. If you're that thin skinned you truly might want to rethink being part of this forum. Again - simple advice.
 
There was never any attempt to belittle you. We've all been there and still need help periodically. I simply made a few suggestions to help you. If you're that thin skinned you truly might want to rethink being part of this forum. Again - simple advice.

Hah! No I'm not thin-skinned at all, I just didn't want to be barraged by annoying "use the search function" posts that seem to plague most forums. Figured I'd head it off at the pass.

I dug through the Sanyo 20EZ postings in the monitor subforum, and it looks like someone with a DK Jr had a picture posted with exactly the same brightness/jailbar issue I'm getting. The solution had something to do with adjust the output from the flyback. I have no idea what that means...but I guess I'll do some reading and figure it out.

It doesn't sound like that will fix my centering issue. It's also possible that my centering issue is a "stretching" issue (basically the top line of text is off the screen) Right now, I don't know if this is because the screen is too high, or because the image is too large.
 
Well, a pic would help but I will list the adjustments that are usually needed after a cap kit on a Sanyo ( at least the ones I've done)

Focus - on the flyback
Screen - Also on the flyback. Controls main brightness (this is probably what you need to turn down.)

Red,Green,Blue bias- on neck board also the drive pots
hsync - center of the chassis VR301
B+ - VR601 left side near heatsink should be +108VDC
Vsync - remote board
Bright - remote board
Vsize - remote board
Hcent - remote board

And the two that people usually miss.
These are usually tweaked because someone in the past has tried to adust them to a failing monitor as with some of the other adjustments.
Hpos - VR1 game PCB
Vpos - VR2 game PCB
 
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Well, a pic would help but I will list the adjustments that are usually needed after a cap kit on a Sanyo ( at least the ones I've done)

Focus - on the flyback
Screen - controls main brightness
red,green,blue bias- on neck board also the drive pots
hsync - center of the chassis VR301
B+ - VR601 left side near heatsink should be +108VDC
Vsync - remote board
bright - remote board
vsize - remote board
hcent - remote board

and the two that people usually miss these are usually tweaked because someone in the past has tried to adust them to a failing monitor as with some of the other adjustments.
Hpos - VR1 game PCB
Vpos - VR2 game PCB


Thanks. This is the kind of specific suggestion I was hoping for.

Hopefully, with the help of the manual that was posted up-thread, I'll actually be able to find all of these things to tweak/adjust :p
 
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