Main > Monitor/Video Forum
Wells Gardner D9200 - Horizontal Collapse?
grantspain:
k7500 will not run on a d9200, yoke is very different
a d9400 or d9800 will run on your tube
the reason no one want to work on these chassis is partly down to the yokes corroding, there is a paint used on these tubes that flakes off into the yoke and rots through the windings and then causes a short. When that happens the chassis will fail every time, sanwa pfx suffer from yoke corrosion as well.
Proving your yoke is ok is the first step, only real way is try a known good chassis. You can remove the yoke and inspect, you would see areas of burn or rot if it has corroded
Rocketeer2001:
The K7500 was rebuilt, so I asked for the horz and vert impedance numbers and compared them to my yoke and they're way too far apart for this to work, like you said. Probably has something to do with the D9200 being a trisync.
I could ask him if he has any D9400 or D9800's.
If this yoke winding coating rots away and causes a short, wouldn't that show in a resistance or impedance reading?
When the monitor was working I noticed the image was rotated slightly. From past CRT experience I knew you could loosen the neck clamp and rotate the yoke to straight that out, so I tried that and the yoke wouldn't budge. I read somewhere on this forum that these yokes are glued pretty firmly to the tube and can't be removed without wrecking them. Not sure if that's true or not. What's your take?
I may be back on the "use tv as monitor" train. I realized that the Big Buck Hunter game board is essentially just a computer motherboard, and like any other computer you don't switch monitor resolutions using the motherboard, you use the operating system. My theory is the Kit version of this game that you'd buy for retrofitting an old cabinet, came with a slightly different hard drive that had the programming to allow you to use the resolution dip switches on the motherboard.
I just need to find a copy of that game, clone it onto a compact flash card, slap it into the game board and see if I can switch to standard resolution. I suspect it would work.
Anybody got a CHD of the kit version of Big Buck Hunter II Sportsman's Paradise?
grantspain:
in my experience you will not be able to read a short on a yoke as it tends to manifest itself only when energized
bonded yokes are not impossible to remove but you do need to be extremely careful
I think your best way forwards is to try to locate a working d9200,9400 or 9800 chassis and hope your yoke is ok
Rocketeer2001:
Hey Grant,
I told the guy that's selling the k7500 my woes and he chimed in that he has a monitor he can pair with the rebuild chassis board. Then I'd have a med-res chassis with a compatible yoke tube. He wanted $500, which is probably fair, just not sure if I want to spend that much and to drive 8 hours each way to get it. I'll consider this the new Plan B.
Someone else pointed out that the hard drive likely won't have any resolution settings on it, nor the eprom chips. They found another blurb in the manual that I failed to notice, which mentions that the low-res setting will only work if I have a special Monitor Scaler Board, whatever that is. The manual also lists the package contents of the 'kit' version of the game, and this special board wasn't included. Can't find any part numbers for that special board or any mention of it anywhere in the community.
Also In summary, different eprom chips won't help me, a different 'kit' game board won't help me, and a different HDD or image won't help me. I need that stupid scaler board that nobody's heard of.
Or, I'm back to tinkering on the D9200 :-\
Rocketeer2001:
While I pondered what to do with my D9200, I put my attention towards making the game run on a Compact Flash Card instead of the original Hard Drive which sounds very much like it's on its last legs.
I had purchased an Eagle V2.09 EPROM boot chip from ebay, which is required for the CF card to work. I wasn't sure if the chip was legit or not, so one way to find out is to boot up the system with the hard drive disconnected and see what the boot screen says.
Since my D9200 is on the fritz I thought I should at least be able to hook up an old VGA monitor directly to the graphics card on the game board to see the boot dialog. First monitor I tried would only say "OUT OF RANGE" and displayed nothing else. Second monitor did the same thing. The 3rd monitor also said this, but this one was smart enough to tell me what signal it was receiving. This was great, because now I could test those dip switches too!
I discovered the switches do in fact work! Here's my results from playing around with them:
DIP 1=ON DIP 2=ON (low res) the monitor says: 15.9kHz / 55Hz
and shows a blank screen
DIP 1=OFF DIP 2=ON (med res) the monitor says: 25.7kHz / 61Hz
and shows a blank screen
DIP 1=OFF DIP 2=OFF (med res with Low res B adjust?) the monitor says: 640x480 / 60Hz
and totally shows the boot screen! It's like it's in VGA mode with these settings.
Using this I could now see on the monitor the version of the boot chip, so I swapped out the original to the 'new' one and sure enough it shows it as the V2.09! We're off to a good start.
I made a CHD copy of my HDD and cloned it onto an 8GB CF card, then slapped that in an IDE to CF Card adapter, hooked up the floppy drive power connector from the power supply, and set the adapter to work in 3.3V mode, and it was totally happy! Game booted up nice and fast!
However, this is where things got interesting. I couldn't see the game, I could only hear it playing over the speakers. After the boot screen is done and the game loads, the monitor goes blank and I get that same "OUT OF RANGE" message I had before, but this time it says the resolution is 25.7kHz / 61Hz.
I thought I was in VGA mode, so what gives?
Having DIP 1 in the OFF position meant it was in medium res, so this time I tried it in the ON position to enable Low Res. I knew I wouldn't be able to see the boot screen, and likely wouldn't see the game either, but the monitor should at least tell me the resolution it's running.
I fire it up and during the boot process the monitor says it's in 15.9Khz / 55Hz. The switches work! The boot sequence is working! This is it, I'm gonna get the game running in low res mode!
Then after the game loaded and I could hear the music playing, the monitor was black and said "OUT OF RANGE" 25.7kHz / 61Hz. What the?
Now I was back on my theory that the operating system was setting the resolution, so if I tried different versions of the game, maybe I'll find one that's from a kit? I downloaded and tried CHD version V2.02.11 , V2.02.09 , V2.02.08 and they all had the same result. What did change was the volume, oddly enough. It became quiet and would make subtle squealing noises, like it was picking up interference. When using the HDD, it isn't nearly as quiet, but does still have some of that interference. Extra odd was the volume buttons in the coin door not having any effect to change the volume...a different problem for another day.
In summary, the dip switches work to change the resolution, but my prior assumption that the data on the hard drive sets the resolution must be correct. What else could counteract the dip switch setting after the game loads?
If I could get this thing to stay in 15.9Khz, then I could use a standard TV with an RGB mod, and that 55Hz vertical refresh wouldn't matter since RGB doesn't care about that.