Missing chip on DK JR PCB -- help

hindered

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actually I believe that chip is not there at all..

I posted the same a short while back... and it was explained to me...

I'll see if I can find it...

brb
 
I dont see much on your video... but I just had my board repaired and it was doing the same sound and graphics... it was bad roms...

and also a new sound chip socket and chip...

Thanks for the link to your thread.. that helps. Also, yeah there's not too much to see on the first video.. it's just random quick graphic glitches and if you turn the sound up you can hear like...a kick drum sound + the jump sound going off in a heartbeat rhythm... and then it eventually freaks out into the siren-type sound. The random graphic glitches are different every time I boot.

The 2nd video is interesting to me but it only happened once. The board behaves differently every time I try to boot it, which is odd to me. Maybe I'm wrong, but I'd expect it to fail the same way every time if it was just a corrupt ROM or combination of corrupt ROMs. Could it possibly be faulty RAM?

Honestly I should probably just save the time and energy and ship this off to Mike's Arcade, but I like solving problems myself when possible.
 
On my DK Jr. board it is labelled as DK Jr 1-C 5A

The chip is a M5L2732K

Thanks. Now I'm confused because according to the other thread, that slot is supposed to be empty on most boards. Since the seller I bought the cocktail from claimed "used to work, before going into storage" (and I believe him), I guess I'll buy that it's supposed to be empty on my board as well.

FWIW I thought my 7D rom was in upside down as well, because of this picture... but it turns out my 7D is a different brand chip than the other ROMs in the row, and the silkscreening is in a different spot, causing the label to be in a different spot as well... the labels are in the same orientation so I think my 7D is probably fine.
 

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FWIW I thought my 7D rom was in upside down as well, because of this picture... but it turns out my 7D is a different brand chip than the other ROMs in the row, and the silkscreening is in a different spot, causing the label to be in a different spot as well... the label's are in the same orientation so I think my 7D is probably fine.

Yeah, your 7D looks fine, the notch at the top is the indicator for pin 1 and matches all the others. Sounds like the 'mystery' chip is optional if most people don't have it, yet their boards work...

I'm sure I just saw a thread on here this weekend with another person having a DK board doing similar things to what yours is. Playing the jump noise over and over when starting up, described as sounding like a siren. Much the same as yours did in the video. I'll search around and try and find the thread.
 
There's several different ROM revisions of Donkey Kong Jr. Almost all do not use a chip in that location. There is one revision that uses that chip. That revision is very uncommon (it only surfaced maybe 3-5 years ago....most people don't even know it exists). I've only ever came across it once. The only way to know what revision you have is to run the ROMs through Romident.

Edward
 
There's several different ROM revisions of Donkey Kong Jr. Almost all do not use a chip in that location. There is one revision that uses that chip. That revision is very uncommon (it only surfaced maybe 3-5 years ago....most people don't even know it exists). I've only ever came across it once. The only way to know what revision you have is to run the ROMs through Romident.

Edward

Yeah, I just think it's funny that the first good picture of a DK JR PCB I found on google had the chip. :) But yeah I'm 99.9% sure my board doesn't need it, so I'm back to the drawing board.
 
I can recommend, use who ever you want tho, Dick Milliken for the board repairs..

I just got back both my DK and DK jr boards from him and it was very reasonable... before that he repaired my PP boards...

Prob just the roms... you could try to get a whole set and replace them... or send it off...
 
Prob just the roms... you could try to get a whole set and replace them... or send it off...

Anyone else think this is one/more roms? The board itself seems pretty clean and corrosion-free. What else could fail to cause this? I suppose the answer is "everything", but are the roms the most likely culprit?

Probably no way to test it other than to put in known working roms, or to dump my roms and compare them to known working dumps, huh? What if I pull each rom one at a time and then trying to boot, to see if something different happens? In theory, if all roms are good save one, this would let me identify the bad one, right? Maybe that's just optimism on my part.
 
Last night I reseated all the roms, which looked clean. I also reseated all the processors and proms, the legs of which had turned black over time. I sanded them all clean and replaced them, and reinstalled the board into my DK cab. This time, the board booted up differently with a bunch of graphical glitches, and the intro music (where caged DK is being hoisted up by the two Marios) played repeatedly, but the game still wouldn't coin up. After I shut down the power, the next 4-5 times I tried to boot it it went back to the normal "heartbeat then siren" routine seen in my first youtube vid.

Odds are very good that I'm just going to ship this to Dick Millikan at this point, unless anyone has any ideas. If I do end up doing so, hopefully he'll share with me what the issue was so everyone can learn.
 
Can I swap the CPU out from my 2-board DK board into my DK JR board to eliminate/confirm CPU issues with the DK JR? The chips are labelled differently but I assume they're both Z80 chips? See attached pics.

Edit: Quick search shows that the chip in my DK is indeed a Z80. I'll prob try to swap them out tomorrow.
 

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When I mentioned a CPU problem in a PM to you I meant an overall processing problem. Could be the CPU chip itself or other supporting components. Could very well be a RAM problem.

Only way to find out is to check all of the ram chips and make sure they are working properly. Maybe someone else with more experience in this regard can chime in.
 
When I mentioned a CPU problem in a PM to you I meant an overall processing problem. Could be the CPU chip itself or other supporting components. Could very well be a RAM problem.

Only way to find out is to check all of the ram chips and make sure they are working properly. Maybe someone else with more experience in this regard can chime in.

Mike's arcade repair logs mentions sort of similar issues being caused by bad 2114 RAM. Maybe I'll investigate there after ruling out the z80.
 
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