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Yet another 256 Display issue..

Dreygor

Dreygor

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So I acquired a Namco System 256 with Tekken 5 Dark Resurrection and it worked fine for a few days with no issues. It was a full pull from a dedicated machine (got card reader and wiring, ps2 control harness, power supply .. everything). Over the course of two days the video started getting dimmer and dimmer like someone was turning down the brightness until it reached it's current state in which no video is showing at all.

I have tried 4 different LCD monitors, 2 flat panel TVs, a CRT monitor, and an CRT to VGA converter going to a LCD monitor adjusting the dip switches to match the configuration. I checked the voltage coming from the power supply with a multimeter and the leads read a steady +5 VDC and +12 VDC respectively. I ordered a new power supply just in case (will be here weds). I totally dismantled the unit and inspected the motherboard under a magnifying glass and did not see any visible lifted feet, bad solder points, bad traces or burnt spots. The odd thing is all of the monitors change their display while the game is booting as if the 256 is out-putting video to them but the screen is black.

When I boot the game I can hear the normal beeps, then it says good morning, I can hear the game playing, I can even hear it when I start the game and listen to it play. So the rest seems to work fine.

I am at a loss and seeking help from the gurus here.

*this puts a serious kink in my plans to mount everything to run this thing in a HTPC case and consolize it. On the other hand does anyone know anyone or have a working motherboard/daughterboard from a 256 they would be willing to trade or sell if this proves to be unfixable? I got quite a few games to give up on this project.
 
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What happens if you try and go into test mode?

Pretty sure I've had the same thing happen to me and I was able to reset the game from test menu.
 
Still same thing. Black screen. When you went into the test mode what kind of monitor were you using?
 
Dreygor said:
Still same thing. Black screen. When you went into the test mode what kind of monitor were you using?
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Nanao MS2933 (autosync 15/24/31k)

I always set the 256 board to 31k over jamma mode using the namco converter board.
 
hrm I have not tried it over the JAMMA.

What are your dip switch settings from left to right ... far left for me is game/test mode.

For LCD in game mode that worked before mine was UP (OFF: GAME MODE) DOWN (ON: 0.7V p-p ) UP (OFF: 15KHZ) UP (OFF: SEPERATE SYNC) on thing of note is my dip switches are upside down from the manual. This is from the Tekken 5 Manual which I am guessing is the same across all of the 256 units?

Call me simple but I wish there was a chart that said if you want to run on an LCD without JAMMA this is your setting, to run on JAMMA with a 31k or 15k CRT this is your setting, to run on LCD through JAMMA with a converter this is your setting, to run on a LCD through a converter (utilizing upscaling) using VGA cables ...

T5_DIP_SWITCHES.png
 
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Try changing the setting on Dip #2 this will change the voltage output on the color pins between 3V peak (JAMMA MODE) and 0.7V peak (VGA MODE). This inadvertently changes the brightness of the output.

It couldn't hurt to confirm measuring the peak voltages on the R G and B pins too.

Also do you have any leaking or exploded caps?
The slow dimming seems like the kind of thing a slowly dying cap would do.
 
think I tried that dip switch setting with no results but I will try again.

You are talking about the pins on the backside of the two video connectors on the machine?

vga_pinoutforxbox3608.jpg


I did remove the board and did a thorough inspection I did not see anything damaged or leaking, no burnt smells, nothing that looks like leaking acid .. nothing :(
 
Dreygor said:
You are talking about the pins on the backside of the two video connectors on the machine?
Click to expand...
yeah, whatever wires connect to the Red Green and Blue pins on the VGA connectors

or if you have a JAMMA I/O you can measure right on the edge connector.

you can try the sync signal too, that should be 5V peak regardless of the dip setting.

EDIT: I just had another thought on this.

have you tried another VGA cable? it could be the cable went bad or the contacts on the VGA port are weak.

Might as well check that you're getting a solid ground signal (no resistance) on the ground pins as well since a weak ground would have the same effect as lowering the voltages on the other pins.

If these signals check good at the PCB itself, check them on the other end of the VGA cable, and if they're lower you know the cable is likely to blame.
 
This sounds really strange- Only time i've ever seen similar was on GBS8220 and similar when the settings were wrong in the OSD.

If you do end up needing a replacement 256, I've got a number in stock, drop me a message.
 
I reset my GBS8200 and put it in automatic and still nothing. I checked it with my 246 (Soul Calibur 2) unit and it plays just fine using all the same parts I use on my 256.

I don't have my multimeter handy so I am unable to check voltages, I will check that tomorrow.

I am preparing for the worse and starting to look for a new motherboard.
 
gotcha good test.
low voltages on the 246/256 in my experience cause non-booting- usually system won't power up if 5V isn't stable, but 12 is only needed to spin the HDD/DVD drive, and you'd be getting load errors, not video errors.
 
Sounds like your board developed a fault on the analog circuitry which handle the RGB output. They have a SONY DIP IC which is a software controllable RGB amplifier. You should check it and the surrounding caps.
 
l_oliveira said:
Sounds like your board developed a fault on the analog circuitry which handle the RGB output. They have a SONY DIP IC which is a software controllable RGB amplifier. You should check it and the surrounding caps.
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Is this something that a non PCB tech who can't solder can fix? I know how to do simple stuff but I know when to admit I am over my head.

At this point I feel I need to send it off for repair or replace it. As much as I would love to fix it (I hate wasting things) I feel it's more cost effective to replace it. After shipping to and from, repair costs and parts .. it would probable be quite a bit to get it repaired unless I could find a kind soul or someone close to Savannah, GA (USA).
 
I know my personal experience is that if the Card reader board (EXCard) is installed in the 256, and the card readers are not connected and powered, the system will not boot properly.

At least that is what my system does if I have that board installed and do not have the card readers hooked up and powered.
 
gamemaster14 said:
I know my personal experience is that if the Card reader board (EXCard) is installed in the 256, and the card readers are not connected and powered, the system will not boot properly.

At least that is what my system does if I have that board installed and do not have the card readers hooked up and powered.
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That's odd- all 4 of my main 256's run with excard installed and i only connect readers when i'm playing games that need it.
 
No ExCard is not installed it is running without it. In fact here soon it looks like defor will own the complete card system out of it.

I was actually able to play the system for a while until the video went out. I can still play it blind .. I can hear the credits sound, I can hear the game starts, I can hear my character start fighting, I can hear my character getting his but whooped....
 
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