PDA

View Full Version : Need help with screen problem on Midway TouchMaster 4000



bill_loguidice
14-04-09, 01:25
I received it today. The shipping carton was beat up, but it appeared to be OK on the palette. I plugged it in and it worked fine for a few minutes, but then something inside popped and now the screen has a purple rolling hue and you can't see anything but the purple. The touch screen still responds to touch and it still makes noise. Any thoughts on what might have blown? I left it on a bit and it sounded like something else might have blown and it has a more reddish hue now. I turned it off.

I have some photos here of it with the purple hue:

http://www.flickr.com/photos/loguidice/3439318583/

http://www.flickr.com/photos/loguidice/3440130062/in/photostream/

http://farm4.static.flickr.com/3404/3439318583_1cd51e09b4.jpg

http://farm4.static.flickr.com/3379/3440130062_36bbe90fa8.jpg

SubaruBrat
14-04-09, 11:56
I think you have two issues at least. The pop was probably a capacitor, that is backed up by the lines on the screen. You can do a "cap kit" that replaces all the major and commonly failed caps in a shotgun repair for usually less than $10. Once you do that I suspect the color problem may still be present. Start looking at the neckboard (PCB on the back of the tube) and work down from there. It may be a driver for one of the guns. It was probably bad before it shipped because they often fail slowly, I hate to say that but it happens. Worse case is the gun is dead and therefore the tube.

bill_loguidice
14-04-09, 04:51
I think you have two issues at least. The pop was probably a capacitor, that is backed up by the lines on the screen. You can do a "cap kit" that replaces all the major and commonly failed caps in a shotgun repair for usually less than $10. Once you do that I suspect the color problem may still be present. Start looking at the neckboard (PCB on the back of the tube) and work down from there. It may be a driver for one of the guns. It was probably bad before it shipped because they often fail slowly, I hate to say that but it happens. Worse case is the gun is dead and therefore the tube.

Thank you so much. I'll try to post pictures later tonight and perhaps you might be able to point out what you mean by caps and how to go about repairing them if you don't mind too much? I honestly don't know a thing about that kind of stuff.

It was actually working fairly well and I was setting it up for free play and all that, but after being on for about 20 minutes, something inside popped, bringing up the purple screen, then after being on a bit longer, something else popped making the screen a bit more reddish. I suspect there was some damage in shipping which I'm trying to address with UPS, because there were some snapped plastic clips on the motherboard inside the unit when I inspected the internals.

Sadly, it seems shipping arcade-style machines is always an issue (or anything with a significant tube-type monitor in it), as even my MAME arcade machine had shipping issues and that was shipped special on the back of a truck and palletted.

SubaruBrat
14-04-09, 05:29
The chassis (PCB) for the monitor could have contacted the frame, look for black marks and arcs to the metal surround. Caps generally fail slowly, not all at once, and not in groups. They can fail at once but usually at power up. The fact that two failed is really odd. That is of course assuming they are failed, it could have been transistors in the deflection circuit but I would think caps first.

A capacitor is a very easy to replace component, it has two leads and polarity is marked. The kits usually come with a set of all the values needed and a sheet showing which one belongs where. They are easy to find on ebay, and by google. First task is to find out what monitor you have. There should be a label on the unit or some model number and brand on the PCB. Once you know that you can search for it by model name (eg "wells GO5 cap kit"). It may be that one is not available for your monitor. You can then look into replacement chassis or just replacing the whole monitor. One other option might be to send the board off for repair, but it would be more expensive than the others.

Here is a really good tutorial on how the whole process works.



http://www.rotheblog.com/2008/02/arcade/video-tutorials-working-arcade-monitors/

bill_loguidice
15-04-09, 08:57
Thanks, that seems helpful, though perhaps still a bit beyond my skills. I'll have to investigate the information further.

I filed a claim with UPS and the seller also offered me a replacement unit. So I have to see what's happening with the damaged system before doing any repairs on it.