F15 Strike eagle monitor problem MI

mcbirdman

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Hello, My name is James and I live in Lansing Michigan. I have a sit down version of f-15 that has a Zenith 25k8102 monitor in it that doesnt warm up. I took it to Tv store and they said that even if they had schematics the Zenith Sets were known to only last around 7 years. The neck of the tube doesn't warm up orange and he said that it what usually goes.

I looked up some specs in the IAM and see someone says it is 576 pixels and 57.00 refresh. Is that considered normal or a problem?

I bought one of those converter boards that goes CGA to VGA but it isn't working in this application. I was excited to find this site and read all I could in order to save this game. With great anticipation I recieved the CGA/VGA board in the mail. I installed it as per instructions but still have an extra wire. Occasionally on the LCD monitor coming out of the board I can get the screen to show the game screens but always rolling around and moving so I wonder if there is something about the sync in these games being unique.

What I would like to do is get this running and not have to spend another 3 days second guessing everything. This game was all torn apart but I got it so it accepts coins, fires rockets,chafe and joystick runs. I got all the wires put together and even made it to the 2nd level without the monitor working. Now if I could only figure out what I NEED to do to make it work so I could SEE the game when I am playing it. I think this game is kinda rare and hate to switch it to a computer case that plays microsoft flight simulator.

The monitor had a 10 pin plug in this order as good as I can figure.
10-red
9-Green
8-Blue
7-RGrnd,GGrnd,BGrd linked together on a black wire
6 empty
5 empty
4 empty
3-Black wire on schematic going to pin 1 which doesn't even show a wire there so what do I do with this? It is unattatched right now.
2-Vert Sync
1-Horiz Sync

so is ground the 7th wire? Is it grounded somehow special I don't understand on 3rd??
Number 5 wire is obviously coming and going somewhere. There are other holes in the plastic plug without wires so why is 5 there?

I wish I knew more, I hitched the combined Rgrnd,Ggrd,Bgrd as negative on the converter board. I used the converter board output to try a LCD monitor and an old computer moniter. It occasionally flashes distorted images of the game in play so I think that either the vga monitor or board isn't syncing or the scan is wrong, but at least the game is trying to put out video images. Anyone who can help me? Do I have to go to a tube or does someone have a used on that would work?

I think it is really cool to find this forum. Especially cool to find some other people with F-15 Strike Eagle Arcades !

On page 97 upper right - http://www.arcade-museum.com/manuals-videogames/F/F15.pdf

....it shows the video connections. I would appreciate it if someone could tell me if the 3 wires linked together are to a ground. Since the monitor is out I don't have the BIG transformer installed that looked like it was for the monitor setup. Do I need it? The wires are numbered different but it still makes me wonder what is the black wire on the schematic that comes out number one pin and ends up the black wire on the molex position 3 wire? Is there another sync? Is there a special ground ? I am stuck !
 
After an hour and a half of reading, just to get to the bottom of the post.

You have a video cable with a shielded ground and twisted pairs. The 3 AGND's go to pin 7 and the shield Gnd (BGND) goes to pin 3.

The actual ground will most likely be the BGND, as the AGND's come from the boardset.
 
Thank you Dokert. I appreciate the information. Sorry if I was too long for you, Really - 1.5 hours to read a few paragraphs? You must be kidding, right? I was just trying to put a personal side of something we are trying to fix and we are happy to have found this place.

I appreciate you backing up the info and further explaining the shielded ground. You are correct that there is a shielded cable. I guess I don't do anything with the leftover black wire.

That means that I just have to get a replacement monitor or find someone around here that may have a monitor I could try or send to them to fix? I think I read that it may be a med resolution monitor but not sure. I cant get any information on the Zenith 25K8102 so I am not sure what to do next other than to keep it short (er).

Thanks, jtm
 
That uses a medium resolution monitor... so you'd need a converter that could go from EGA (not CGA) to VGA, if you're wanting to replace the monitor with a VGA monitor.

There's likely a repairable problem with your existing monitor though. If you just want it fixed and don't have the desire/skills to look at it yourself... it looks like http://www.arcadecup.com/ can repair it if you ship him the monitor boards (for $110, or $140 if it needs a new flyback). Otherwise, I'd pull the monitor boards, inspect them for bad solder joints, burnt components, discolored connectors (sign of bad connections), blown fuses, etc... then report back here.

DogP
 
Thanks Dokert, again, I appreciate your help. You are correct as I investigated the monitor componants and indeed it is the Wells Garner 25K8000series. I appreciate the Manual (link) and the good info. Thank you.

DogP. Thank you for letting me know it is med resolution. I did buy that 39.00 conversion board cga to vga and it spuratically flashes unsynced images of the game playing if I tweek the settings but is useless.

Since the TV shop said there wasn't much they could do without the schematic but also noted problems with the Zenith Tubes.... Is it True? And is it worth it to get the boards checked out only to have to still find a tube? Are they mostly interchangable or even available? Do I just go get a Makvision 29" and make it fit? lol?

I will take DogP's suggestions and look at the boards. I have seen a dark spot on the board near a pot that looks amber that I have been wondering about. I wonder if something was spilled in the top vent which eventually shorted something out.

Thanks for the suggestions and pointing me in a good direction.
 
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Schematics are available, but typically TV shops are clueless on repairing arcade monitors. While yes, some tubes do go bad... they typically get weak/lose a color... if you're getting no neck glow it's more likely that there's something wrong with the boards (chassis).

If you can, take some good close-up images of some of the boards (and even of the bottom sides)... we can probably point out some trouble areas.

DogP
 
DogP is correct, 9 out of 10 TV repair shops don't know jack shit about repairing arcade monitors these days. It is like going into Radio Shack and asking them for something other than a new cell phone or a battery.
 
f15 monitor problem

Thanks guys. I appreciate your interest. I will get you photos. I don't mind looking at the boards-just needed to know if the tube was likely culprit. Encouraging that you think no tube warmup maybe board. Looks like it is worth trying.

I looked at site and they don't list specifically GW 25k8102 on his repair page. Says 8000 but then some stuff in special notes that I don't understand.
 
I looked at site and they don't list specifically GW 25k8102 on his repair page. Says 8000 but then some stuff in special notes that I don't understand.

I assume you're talking about on the Arcadecup website? Those numbers are the specific monitor board numbers... if you look closely on the boards somewhere you should see a number P6xx.

Also, I'm assuming you're familiar with monitor safety? Of course ensuring the monitor is off/unplugged when you're in there, and also discharging the tube before working on it?

DogP
 
Thanks, Will read numbers on board and take photos for you when light is good tommorow. I did find the sticky notes on monitors and am still reading.

I have been staying away from the wires, especially the big red one going into front of tube. I'll read about discharging since I may have to remove boards from chassie to send into arcadecup you mentioned - if he does those boards. Thanks DogP for the concern, I will read before proceeding.
 
K8000's are known to develope cold solder joints on all the pin headers (connectors on the boards). They also LOVE to have big holes burned into them thanks to the cold solder joints. Specifically the harness that connects the power supply boar (the small board mounted on the side of the frame) to the delfection board.

Its amazing how clueless TV shops are when it comes to these arcade monitors. The monitor is basically a TV missing the tuner but they cant see that. If you have any ability with a soldering iron you should be able to fix the chassis or at least figure out what the problem is. Chad at arcadecup can fix those board if it comes down to it.

Good luck.

Matt
 
BTW, for some reason I'm thinking that F15 Strike Eagle is VGA not EGA. I'm not sure why I'm thinking that but I seem to recall this from working on one ages ago. I think theres another game (B.O.T.T.S.) thats based on similar hardware and I'm pretty sure its VGA as well. K8000's are capable of running at medium res (EGA) and VGA depending on the model and chassis modifications so I'm not 100% sure about this. When you take pictures we can be sure or not. The EGA model has way less parts then the VGA model does.

If it is VGA its probably running at 640X480 which means any PC monitor should be capable of displaying the games picture, you just need to build an adapter. Based on the harness running up to the mointor from the game boards that "sounds" like a vga cable cut open. Each color on a VGA cable has its own ground (they are all coneected).

Sorry about the long read Dokert! LOL!
 
Hi Gamefixer- Interesting points!

On the museum information page about F-15 it says that the game is 576 x 400 and 32768 pallete. If this information is correct does this still support idea this is VGA? The cable is a shielded cable and I think there are at least a couple extra wires in it not used.

If it is VGA it would explain why the conversion board not being able to autoscan correctly. I would be feeding VGA into a CGA/EGA to VGA converter....

In order to get you decent photos I am trying to get a camera that does closeups so that you won't have to struggle with blurry camera phone photos. Those make me dizzy AND sleepy.

How are you able to help if you don't have the information you might need? I know I am limited in knowledge in this area but I am trying to roll up sleeves and do what I can. I have a couple other games that need to be fixed next but this means the most to me.
 
576X400 is probably an EGA resolution or perhaps its the size of the image displayed on the screen? I really dont know but I still think that the game will display on a PC monitor capable of displaying 640X480 @ 31khz. Some new LCD's wont go down to 31Khz so dont be surprised if you cant display the image on an LCD.

Read up on how to spot cold solder joints. I'd be willing to bet your going to find a lot of them on that chassis.

One thing you can do thats quick and easy is check the fuse on the power supply board. If its good you probably have cold solder. If its blown to bits then you have some issues with the mointor chassis and maybe even the power supply.
 
Hi Gamefixer. Recharged the camera battery and was taking photos. I put an ohm meter on a post that had obviously been hot. Actually two pins had gotten the plastic connector hot enough to mark it. I resoldered a cold crack like you had predicted and put it all back together. Although the tv tube humms it doesn't warm up yet. I guess tommorow I will have to go over it in better light. I must be missing some more cold cracks. I'll look again tommorow and see if we can find it.

Thanks for the hints. I hope we find it and will keep ya posted. Thanks, jtm
 
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