DONT Need help with a mega touch, it WORKS!

[stevejt]

Hello all.  I just got a mega touch for nothing, so I'm not complaining.  When powered up, the screen is unreadable, and you can hear a noise like a static buzz.  It looks and sounds EXACTLY like when you get the wrong refrech rate on a pc monitor.  I tried all the standard monitor adjustments and they didn't help at all, but did seem to move, stretch the screen or what ever they were listed to do.  The main board for the monitor, not the one attached to the neck, looks a little corroded.  I have seen worse one work.  I have absolutely no experience with fixing monitors, replacing touch screens, or mega touch's in general.  I would like to get it working.  I don't know if its worth it to try to clean up the board.  Or if I should/can replace the corroded board.  Or what type of monitors can be put inside.  I don't even know if the main game board works.  I was told it worked a few months ago and was stored in the basement, and hasn't been powered up since.  I would appreciate any suggestions.  The cab is in excellent condition and even has a bill acceptor.  I was also given a terra cresta, that I was told had a blown fuse.  Pics of the mega touch are here:

http://www.stevejt.com/~megatouch/

They were taken with my cell and a flashlight, so thats the best I can get for now.

Thanks In advance!

Steve

[stevejt]

I didn't take a pic of the monitor, because I didn't want to power it up any more.  But it looks and sounds EXACTLY like the wrong refresh rate on a pc monitor.

Steve

[Ken Layton]

That's a PDT 4019v monitor. They were eventually bought by Ducksan. Ducksan went out of business in 2003.

I've seen enough of your pictures to make some determinations:

1. This thing has either been in a flood or very damp location.

2. The corrosion is some of the worst I've ever seen to make repair of the chassis economically unfeasible. This is very very bad.

3. I suggest ebaying the monitor main board, neck board, and remote adjustment board as "salvage" or "parts only".

4. The picture tube, yoke, touchscreen glass, and monitor metal frame are probably ok and reusable.

If you can find a universal replacement monitor chassis then get that. This is a VGA resolution monitor.

Otherwise you're looking at buying a new VGA resolution monitor and carefully transfering the touchscreen glass from the old monitor to the new one. If you were to buy a brand new monitor with a touchscreen glass on it already, you'll be looking at a very expensive monitor. Happ Controls has their number 49-0824-00 which is a Wells-Gardner 19" with touchscreen glass attached. Hold onto your hat when you hear the price: $716.60

[stevejt]

Thanks Ken.  I knew you would come through.  Yes, the basement I pulled it out of was wet, beyond just being humid.  Can you be more specific as to what kind of "universal replacement monitor chassis" I should look for.  A sticker somewhere said only replace the monitor or board with one that DOESN'T use a transformer.  I would hate to waste my money on the wrong parts AND ruin the tube...  I really don't know anything about monitors.

Thanks Again!

Steve


edit:would this be compatible, sorry if it's a stupid question...  ebay item number 270022889445

[Ken Layton]

Steve:

No that ebay one is the wrong resolution and it's for a 13" tube.

If you have some soldering experience you could try installing some new capacitors on this chassis. It might fix it, but be carefull soldering/desoldering parts on this circuit board as the copper foil traces lift very easily. New capacitors wouldn't cost much to try in order to see if that fixes it. Judging by the amount of corroded components on your chassis though I doubt it could get this going.

In order to determine which universal chassis would work on this monitor, I'd need to know the numbers off of the picture tube. Is this a 13" (starts with A34xxxx) or 19" (starts with A48xxxx). Next thing is to check the resistance of the vertical section of the yoke wires. Usually the green and yellow wires of the yoke connector are the vertical section. You'll need an ohmeter set on it's lowest scale. 16 ohms or less is considered a "low impedance yoke" while 33 ohms or greater is considered a "High impedance yoke".

Once I know this I can recommend the correct chassis for you to order from Alva Amusement in Florida. I think you'd be spending around $65 for a replacement chassis which would include a main board, neck board, and remote adjustment board.

If you have a VGA computer monitor kicking around, you can unplug the games' monitor from the Megatouch game board and plug the computer VGA monitor in instead just so you can see if the Megatouch game comes up (thus verifying the gameboard and game power supply are working.

[Angry_Radish]

It's going to take more than just caps, did you see the corroded resistors on the board?
I agree with the possibility of the tube being good, but the chassis is shot

[NightGod]

Not too often you see resistors so corroded they crack.

Most impressive.

[stevejt]

I'll try to get the info for the tube tonight.  Took a quick look and no green, looks like blue, but perhaps WAS green.  I'll take measurements between them all.  Also didn't see any numbers on the tube itself.  Would they be somewhere specific?  Or could they be anywhere?

Thanks

Steve

[Ken Layton]

There should be a paper label with the tube manufacturer's name and tube number afixed to the tube itself.

[stevejt]

Okay Ken, here's the info you asked for. 

Model number is A48QAD220X    08

14.7 ohms

Not sure if I did the ohm testing correctly.  (I know how to use a meter.)  The copper colored "magnet wires" attach to pins on a tiny board.  The only measurements that came up were 2.6 ohms across bottom 2 pins and 14.7 across top 2 pins.  I Did NOT remove the neck board to test.  I figured if it would mess it up I wouldn't get anything close.

Thanks Again For All Your Help!

Steve

[stevejt]

I don't usually seem to get any good deals.  So I was rather surprised to when I responded to an ad for 2 free games, and they were still there. So I picked up 2 FREE games the other day.  A terra cresta, and an EXCELLENT condition mega touch 4.   When turning on the mega touch, the screen looked and sounded like when you have the wrong refresh rate on a pc monitor.  I looked inside and the thing was as corroded as the titanic.  (It was in a wet basement.  I was told it worked when put down there a few months ago, but can't take it where the owner is moving. ) I posted here and was told to give up on the monitor chassis and replace it.  I figured I have nothing to lose if I try to fix it, so I told myself I'd fix it if I have to change everything on the damn board.  I have never ever done any work on a monitor so I was terrified just trying to discharge the damn thing.  It was funny enough me telling my step father to do it, he said I should do it, back and forth.  So cringing like a little baby I tried to discharge it.  The worst thing was that it made absolutely no noise.  So I did it about 10 times.  Then some more.  I then took out the boards for the monitor.  I found a resistor that wasn't connected on one side, so I fixed that.  It had a cap kit done, and some of the solder looked cold, so I reheated them.  I then took off some of the bigger caps that looked like they had corrosion coming out from underneath.  I cleaned them all and reinstalled them.  After cleaned they didn't look like the crap was from them.  I cleaned alot of crap off the board with a childs tooth brush and rubbing alcohol.  I spent 3 hours on the damn thing.  While putting it back together, I realized there was a wire broken off.  It went from the what I beleive is the flyback, to the socket the tube neck goes in.  It broke INSIDE the socket.  SO I had to break away some of that and then solder it INSIDE.  More fun and time.  So just as I was about to put the last plug back on the board I saw something....  One of the tiny clips inside the plug was BROKEN.  It made sense, resembled an non compatible refresh rate.  I guess it was a f-ing SYNC wire that was loose!!!!!!!!!!!!!!!!!!!!!!!!!    At 1:30 in the morning with everybody in the house sleeping I started screaming and cursing.  I have load of parts but couldnt find a video plug anywhere.  I ended up ripping, yes ripping one out of an empty cabinet and doing a 30 second splice job with a bunch of tiny wire nuts.  Guess what...  It works...  I would love to think that my keen eye, and NASA quality soldering skills had something to do with fixing the game.  But that would just be total BS.  So after about 4 hours, I did a 1 minute fix....  The worst part is when anybody that ever asks me about problems with arcade games I tell them that FIRST thing is check all the plugs....

So, I did I get the "find of the month".  The thing has like 20 games on it.

In case anybody was going to ask, I don't even know if the terra cresta works, it's still in my truck..

And Thanks again any way Ken, for your help.


Steve

[SirPeale]

That wire that goes into the neckboard socket was necessary as well.  I *think* it's the focus wire.

[SirPeale]

Plus reflowing solder on bad joints is always a good idea.

[stevejt]

That wire that goes into the neckboard socket was necessary as well.  I *think* it's the focus wire.

I am guessing that with the hours of flipping it back and forth in the workbench, (well really it was on a freezer...) might have been what broke it.  Where the wire was broke it was not tarnished, which looked like a new break.  I guess I have "1 cap kit" experience, even though I didn't do one...  And I am glad I read before hand that one cap was marked wrong on one side of the board, that would have really been confusing had I not.

Steve