moonwalker system 18 sega problem

PCB problems and fixes
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snk80
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moonwalker system 18 sega problem

Post by snk80 »

hi guys.
i need a help
i take an original moonwalker. it seems doesn't boot.. it stops at first screen
i have tryed to disconnet jamma cable and shot down the system.. sometimes star another screen with random credit.

i verify gpu and it has 3,2 volt

this board seems to have problem on starting... someone know anything ?

regards
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Asayuki
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Re: moonwalker system 18 sega problem

Post by Asayuki »

Shot in the dark: If it doesn't lock up the same way every time, you might have a loose joint around.
My 15kHz cabinet Peplos will never power up, with any item, and I am quite proud of that.
snk80
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Re: moonwalker system 18 sega problem

Post by snk80 »

mmm not
i talk with a friend maybe are two eproms for boot. that two that you have to change when suicide the board ;)
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leonardoliveira
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Re: moonwalker system 18 sega problem

Post by leonardoliveira »

On most computers here's a circuit with a capacitor where the charging of the capacitor controls how long the system master reset control line is held down during the power up. That behavior prevents that some parts of the system start up earlier than the CPU is able to take control of the system, keeping everything synchronized at the time the CPU is ready to start.

If the capacitor is bad the master reset pulse may be shorter than the required, causing the system to malfunction exactly at the power up time.
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segasonic91
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Re: moonwalker system 18 sega problem

Post by segasonic91 »

Is it feezing at the MJ logo/title screen or when you actually start the game? I have seen a repair on youtube for the Micheal freezing on the first stage and it was 2 bad sound chips. If that is your symptom, try looking it up on youtube.

I was about to buy a Moonwalker board from a website in Japan for what I thought was the bargain price of ¥16,000. Then I noticed that in the description that it mentioned the freezing thing. I also noticed that the photo showed a D.D CREW motherboard, although it could be stock. There was no mention in the description about mis-matched motherboard.

I was trying to find the specific video on youtube, but could not locate it. It seems to be a very common problem on that board though. The sound chips are connected to the cpu in some way which causes the freeze if they are not working.
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rodwod
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Re: moonwalker system 18 sega problem

Post by rodwod »

Its dead jim.
You need to replace the 2 eproms and FD unit with the correct processor and it will be good to go.
I don't think its well documented but different system16/18/32 games and different revisions of those games will act differently when the battery dies.
For instance some game will just loose the sound but still play...I think i'm correct in saying this :)

I can help with that if you need it.

I was about to buy a Moonwalker board from a website in Japan for what I thought was the bargain price of ¥16,000. Then I noticed that in the description that it mentioned the freezing thing. I also noticed that the photo showed a D.D CREW motherboard, although it could be stock. There was no mention in the description about mis-matched motherboard.
From my expirience it seems that the japanese do not like to mess with their pcb's much :) when its dead its dead.Which means great deals can be had by all :)
Last edited by rodwod on October 22nd, 2017, 9:08 pm, edited 2 times in total.
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leonardoliveira
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Re: moonwalker system 18 sega problem

Post by leonardoliveira »

I think one with a dead encryption processor doesn't even give out any video?
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rodwod
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Re: moonwalker system 18 sega problem

Post by rodwod »

Oh :problem:
In that case maybe some pcb pics will help.
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leonardoliveira
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Re: moonwalker system 18 sega problem

Post by leonardoliveira »

My suggestion is, considering that it boots, go into the service menu and run the memory test option.
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RMRM
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Re: moonwalker system 18 sega problem

Post by RMRM »

I would simply open the CPU (be VERY careful with the earth wire) and simply measure the battery voltage. Easiest test you can do right away to have some definitive answer about the suicide thing.

Then you go from there...
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leonardoliveira
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Re: moonwalker system 18 sega problem

Post by leonardoliveira »

If it still have the FD1094 and gives video it can't be suicided.

The FD1094 is the game CPU. If that fails the game won't boot. You will get a solid black screen.
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rodwod
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Re: moonwalker system 18 sega problem

Post by rodwod »

leonardoliveira wrote:My suggestion is, considering that it boots, go into the service menu and run the memory test option.
Yep & Clear the back-up data.
Last edited by rodwod on May 9th, 2018, 4:27 pm, edited 1 time in total.
snk80
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Re: moonwalker system 18 sega problem

Post by snk80 »

solve.. just for info to the user of this forum..

there are 2 eprom that i think , help the boot..
one was faulty... it was not che cpu ;)
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Re: moonwalker system 18 sega problem

Post by caius »

leonardoliveira wrote:If it still have the FD1094 and gives video it can't be suicided.

The FD1094 is the game CPU. If that fails the game won't boot. You will get a solid black screen.
It'd not a rule.Sometimes it can happen that, although with a charge battery, only some bits of the RAM inside the module go bad (technicall it's called 'bit rot") so the game will crash always at same point.
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