Defender cab with video issues- please help !!

[kjoel0123]

Just picked up for a bargain. Game plays here and there. Sound and controls seem to work. Video is streaked and there is snow on the screen. All connections seem ok. chips are all seated. See pic for details

I am new to defender cabs. I know this has a bunch of boards, any one board in particular? Bad crt? Bad game board?

Thank you for your assistance. I need to know what to check first

[grantspain]

have you tried the horizontal hold yet to lock the picture,checked all connector and the power supply voltages?

[kjoel0123]

adjusted both the horizontal and vertical holds to no avail. Have yet to test voltages. Game play does work. I see that there are 5 boards-
1- sound pcb
1- power supply pcb
1- control panel pcb
1- rom pcb
1- main pcb
Crt does glow at the neck. Went to klov.com to view schematics.

Anyone know what the AA batteries are for on the main pcb?

[Paladin]

Batteries are used to save high scores, also if you don't have batteries the game will always start in test mode when powered on.  Best thing is to remove the battery holder and replace with a lithium button cell.  Cheap and easy swap, a google search should turn up more info on it.

Not sure about the image you're getting, I'm still trying to get my Defender cocktail going.

[kjoel0123]

I will replace the batteries soon and use lithium. Thanks for the tip.  I am still trying to figure this video issue out. I will keep digging..

Tried the horizontal and vertical hold settings to no avail

[cw]

the game looks to be running fine. my money is on the wiring harness going to the monitor or the monitor just needing caps.(thats  red, blue, green, ground, sync, sync) if the harness is good then i would do a cap job on the monitor. (if its not been capped in the past few years you might want to do it anyway)

[Q*Bert_OP]

also, check that the video connector are not miss-seated or "one pin off"

[kjoel0123]

I will check the wiring harness and monitor wiring. I am going to pull the main pcb tomorrow to check what damage was done by the AA batteries as they are prone to leakage. I will keep ya posted..

[RayB]

Definitely looks like HSYNC.
I had that problem on my Centipede and it required re-flowing the pins to the video signal connector on the monitor.

[kjoel0123]

No battery leakage. The monitor wires and harnees wires all look in great shape. Monitor is original from 1981 with an RCA tube. Model # 19VJTP22. Looks dirty as hell too. I think that I just might buy a happ vision pro unit in the near future and pull this one or do a cap kit. Not sure. I dont know if they even sell a cap kit for this old unit. Believe it or not I just bought this dedicated unit at a local garage sale with hand painted art.

[Level42]

Cab pics ??

Is that picture rolling ? If not, couldn't it be a character ROM problem ? I agree that it looks most like a sync problem...

[kjoel0123]

The screen seems steady in place. However the colors seem to pull from the left to the right at times. Is it even worth doing a cap kit on a 26 year old monitor?

[RayB]

The screen seems steady in place. However the colors seem to pull from the left to the right at times. Is it even worth doing a cap kit on a 26 year old monitor?

Post a new photo if it no longer looks like the one up top.

[Darth Nuno]

If it can help, I've done a 'picture by picture' full capkit replacement for my... Defender cab 

Have a look right here : http://www.dragonslairfans.com/phpBB2/viewtopic.php?t=131

..and it solved the geometry problems on it.

But honestly, I would go for a *brand* new arcade monitor now... so cheap in US... lucky men 

[Level42]

Bwahhhh, we've got much cheaper TV's with RGB on the SCART connector

[kjoel0123]

No need to post a new photo as the picture has not changed. I will try a cap kit then if not I buy a new monitor.

[RayB]

When you start up a game, do you see a thin white line of garbage move up & down when you move the joystick up n down?

Humor me and take a long wire... Connect it to the HSYNC output from the board, and run it to the HSYNC input of the monitor.

Also try the HSYNC pot again, but with just light "hair" adjustments. It could be a bad or very sensitive pot.

[SirPeale]

No battery leakage. The monitor wires and harnees wires all look in great shape. Monitor is original from 1981 with an RCA tube. Model # 19VJTP22. Looks dirty as hell too. I think that I just might buy a happ vision pro unit in the near future and pull this one or do a cap kit. Not sure. I dont know if they even sell a cap kit for this old unit. Believe it or not I just bought this dedicated unit at a local garage sale with hand painted art.

That number is the tube ID  number.  Go to the monitor forum and check the READ THIS FIRST thread.

And yes, if it's working it's worth fixing.

[kjoel0123]

Just ordered the 4600 cap kit from arcadeshop.com. I know how to discharge the crt, but do I have to discharge each capacitor before changing or dont bother? If so how do you discharge the caps? The monitor has very light screen burn.

In reply to Rayb:
I do see a white line/ pixels when I move the joystick up and down. I tried the pot adjustments the other day to no avail, I will definitely try the wire from the board to the monitor and let you know and also try the pot adjustment with the wire connected.

In reply to Dart nuno: Thanks for the pics and tips. What watt soldering iron and solder did you use? You did a great job on your monitor.

[Q*Bert_OP]

Don't bother discharging the caps...just keep your fingers on the *outside* edges of the chassis, and you'll be fine...

[kjoel0123]

Will do, Thanks for the tips

[kjoel0123]

Did what you said about connecting the sync wire to no avail. Checked the horizontal pot seems ok.

I also changed the old batteries and now the damn game dont play WTF..

Seems like the bios or menus will need to be reset once I get the screen to work properly I hope

I will install the cap kit once I get it then go from there

[Q*Bert_OP]

I also changed the old batteries and now the damn game dont play WTF..

After the powerup tone, push the "enter" button on the coin door's test panel

[RayB]

Hmmm so could be a board level sync issue....

[cw]

imho
it could be but until he recaps and reflows  (when you do check the adjustment post for coldsolder joints as well and the input molex pins) the monitor i would not even think about much checking on the pcb except for a good looking over.

[kjoel0123]

still awaiting the cap kit.  I tried the enter button- did nothing that I can see cause this damn monitor issue. I will keep ya posted once I install the kit.

[RayB]

Joel....... is this your only arcade cab? You could always take the video output and run it to another monitor you know works.

[kjoel0123]

Good idea. I have 6 cabs now and a mess of boards. I figure that I try to recap it first, then if no good it goes to the trash.  Hell I need the soldering practice anyway. After all it is an original monitor from 1981. Dirty as hell. If it dont work then I buy a new 19" happ unit.

[kjoel0123]

I recapped the monitor tonight and still have the same issue with the colors on the screen. After trying all these steps, now I will try another monitor, then I send the board out for repair. Thanks for all the help !

[RayB]

You can also do the reverse, and hook up the video output from a game you know works, to your Defender monitor. Then you'll nail down the true state of both monitor and boardset.

[kjoel0123]

Right problem is that the defener can is in a different location then all the cabs. I think that I will look for a free 19" monitor w bad screen burn for test purposes. I am sure someone has one !

[cw]

did you reflow the input molex pins?
did you try and adjust the horizontal freq?

[kjoel0123]

I did not reflow the input molex pins. Molex pins all look good. I adjusted the horizontal frequency to no avail. I will next try another working monitor, then the board gets sent out to check that next.

[cw]

You might want to pull the main pcb and reflow all molex connections. Double checking the video output pins...

[kjoel0123]

Will do when I get some time, thanks for the tips

[kjoel0123]

I reflowed all molex pins on all boards and even the transformer connections. Too dark to test, will let you know how it goes tomorrow. All female molex pins look good. Power tested to transformer is good. All led's on power supply light up . Will test the rom board led's tomorrow. Next will be to change out the 24 ram chips then the rom board chips if all else fails. I am getting what they call rug screen with a horizontal line. Believe that the chip change will correct this. We'll see !!

[cw]

defender error codes

http://www.mikesarcade.com/cgi-bin/spies.cgi?action=url&type=info&page=DefenderErrorCodes.txt

[kjoel0123]

reflowed all molex pins on boards.

new updated pic- when unit first boots then it goes to snow here and there

 let me know what you think

No light at all on the rom board, power supply has all lights lit.

[SirPeale]

You have a monitor issue.  No vertical deflection.

[kjoel0123]

Thanks now I need to get a monitor to test, even old w alot of screen burn works for me. I cant pull the working units from my other cabs. I dont hear any sounds from the game playing at all.

[SirPeale]

Did you do anything to the monitor?

[kjoel0123]

Just put a cap kit and it looks the same after the install

[torez]

Is this the Defender cab that was for sale in Queens, NY couple of weeks ago?  The guy had motorcycle, car, fish tank, guitar, etc. for sale.  He said it stopped working after he moved it.

[kjoel0123]

Picked it up in Suffolk. Putting this on hold for now as my time is limited.

[torez]

Maybe it was farther than Queens.  Next to LIE?  Add was on Craig's?  Left sideart was scratched?  The guy's name was Cliff, but his wife Debbie was answering emails.  She said the game worked, but display stopped working after the game was moved.  Sound was still there.  Just wondering, as it was a garage sale and around the same time.