Terminator 2 cab freezes sometimes: heat?

[Cenobyte]

I recently bought a Terminator 2 cabinet and I'm having great fun with it!

The thing is 20 years old and does seem to have a few small problems:

1. the monitor seems to have color problems: in the upper left corner, the color is way off. It's a rather big part of the screen that gradually goes to a blueish color (the green letters are actually blue there). Not a big thing and when playing the game you hardly notice it, but I was wondering if it could be solved? Or is the only solution installing a new monitor?

2. (and this is a bigger problem) the game freezes somethimes with the screen going black, speakers making small popping sounds every now and then and the system sometimes also resets and goes to the scrambled screen that you see when you startup the machine. The machine does not reboot, you'll need to shut it off and on again. It sometimes does this during a game (which is a bummer) but also during attract mode. I pulled out the CPU board and had the cab running for about an hour without the problem returning until I pushed the CPU board back into the cab: after 15 minutes the cab froze again. Could this be a heat problem? Might installing an extra fan directed at the CPU board solve this? Or is it the result of a malfunction somewhere?

[DaOld Man]

I would put a floor fan (the kind that plugs in the wall and maybe rotates back and forth), positioned to blow right  on the cpu board with the back panel open, just to see if this helps. If it does then you might want to look farther down the heating up path. If it doesnt help, its probably something else.
(Maybe power supply over heating?)

[jennifer]

       Cap kits are cheap, most likely fix your monitor. As for the "heat" thing, a burnt connector, [bad ground] on board edge would be my first look.
look at it, wiggle it a little, check all connections. Thermal [heat] problems can be tricky to find.... freeze spray works but this should be your last
resort,  and use sparingly

[Nephasth]

I don't know where the speakers are located on a T2, but an unsheilded speaker near the monitor can cause the type of discoloration you are describing.

[Xiaou2]

Arcade Monitors, when moved, often need to be de-magnatized.  There is a special tool for this very purpose.   PC and newer arcade monitors have the feature built into them.
(dont use a standard magnet, as I believe that can do permanent damages)

As for the freezing, most freezes come from power supply issues.  If the current is too low or too high, it will cause such issues.  The Power supply is also likely to be the thing overheating/failing, possibly due to a failing component, and or possibly clogged with dust.

 Check all voltages, blow out dust when cab is unplugged and cool, check for capacitors that are bulging (raised cap tops usually mean the caps are almost dead, and are not able to operate properly). Also look for soot/burn marks.

 The older arcade PCBs are pretty damn durable.  Heat is rarely an issue for them.  It was only when they got into the hard drive erra, and PC based equipment that heat really started to play a role in machine instability.  The older PCBs were often ran non-stop for days, in high heat situations at the factories before being installed / shipped out.

[mgb]

The monitor probably just needs to be degaussed. There is a built in degaussing coil on the monitor but you'll probably have to manually do it.
Look it up, theres a lot on the subject. you can buy a degaussing coil from several places. I use a bulk tape eraser. it works great

[mgb]

Also as far as the freezing up goes:
First clean the board and fan of dust.
Make sure your voltage is good at the board. This should typically be done by metering the 5volts where it comes in on the board (better is on the grnd & 5v of a chip), while metering for dc voltage, adjust your power supply til you have 5.1-5.2 volts.
I've seen alot of games act up from this voltage being even a small amount lower than 5volts

[Cenobyte]

Thanks for all the help!

I don't know where the speakers are located on a T2, but an unsheilded speaker near the monitor can cause the type of discoloration you are describing.

This can't be the problem, since the T2 uses a monitor that lies flat on it's back and projects the image up to a mirror. The speakers are behind the marquee, far from the monitor 

Arcade Monitors, when moved, often need to be de-magnatized.  There is a special tool for this very purpose. PC and newer arcade monitors have the feature built into them. (dont use a standard magnet, as I believe that can do permanent damages)

I had the monitor in test mode today and when displaying a red test screen both corners were green!  And with "both corners" I mean almost 50% of the screen...

I searched for some kind of degauss or demagnetizing switch, but was unable to find it (not in the manual either). I guess this means it'll probably has to be done the old fashioned way? Is there a procedure on how to do this without electrocuting myself?

I will try to clean up everything as best as I can and check out the power supply, see if that helps me.

[Xiaou2]

As I said, older monitors do not have degauss units included.

 You have to buy something like this:

 http://www.amazon.com/Waldom-Degaussing-Coil-Color-Power/dp/B00011UYJU/ref=sr_1_1?ie=UTF8&s=hi&qid=1300379991&sr=1-1

[mgb]

Yeah, there is no troubleshooting or figuring out to do with that problem on your monitor. It is just from the moving of the game from location to location. Just degauss it and that color issue will go away.
The degaussing coil on the monitor is behind the tube and it kicks in automattically when the monitor is turned on after so much time off. You need to manually degauss with a hand held coil or a bulk tape eraser

[Xiaou2]

mgb - why dont you repeat everything I type so he Really gets it?! 

 As said:  NOT ALL MONITORS HAVE DEGAUSS COILS BUILT INTO THEM!!!

 Especially OLDER ARCADE MONITORS such as would be installed in a T2!

 Ugg.

 
 
 This comes from a guy who managed / repaired arcade machines for 3 yrs of his life, +5 days a week, 9 hrs a day.

[lilshawn]

This comes from a guy who managed / repaired arcade machines for 3 yrs of his life, +5 days a week, 9 hrs a day.

*GASP*
you mean... not everybody here does this as their job?

i mean i'm only 8 hours a day....

[mgb]

mgb - why dont you repeat everything I type so he Really gets it?! 

 As said:  NOT ALL MONITORS HAVE DEGAUSS COILS BUILT INTO THEM!!!

 Especially OLDER ARCADE MONITORS such as would be installed in a T2!

 Ugg.

 
 
 This comes from a guy who managed / repaired arcade machines for 3 yrs of his life, +5 days a week, 9 hrs a day.

I'm not sure about repeating you... but theres one fix for the monitor problem, so only one way to put it. And its regardless of whether or not the monitor has a built in degaussing coil.

[Cenobyte]

I'm not sure the monitor has it's own degaussing coil built in. I noticed a slight improvement in the image yesterday, but still a lot of discoloration. Not sure if it changes when the game is running for some time?
I contacted an "old fashioned" television repairman yesterday (this guy still knows a lot about the old tubes) and he will come over next week or so to check the old tube out.

About the game quitting unexpectedly:
I suspect the power supply too. Sometimes the cab keeps running fine for an hour (yesterday we had great fun with it with the five of us, reaching almost the end of the game, then quitting ) and sometimes it quits on you within 15 minutes. On the moment the machine fails, there is half a second of garbage on the screen (just like when you pull the plug or something) the speakers pop softly and the screen goes dark. All game sounds seize as well, so it's not just the monitor failing and the game continuing, it's the CPU failing.

I checked out the T2 manual and found out that the power supply is putting out +5V (11A) and +12V (2A):



What is the FG connector for? (found it: Frame Ground) It looks bridged to the +5V line? 

Would it be hard to find a new power supply like this one?

Or would it be possible to swap this old PSU out with a different (non-original) one putting out the same voltages? Like a PC power supply (but that will probably not have enough juice for the +5v 11A, I guess)

[Eddie_Brock]

It's definitely possible with a PC Power-Supply (check the output specs beforehand!)
But you may want to at least look around for a replacement PSU, it could be a fairly common replacement.

[Cenobyte]

I did some testing with a voltmeter today and found out that the switching power supply is putting out a very nice and stable 5volts at the +5v terminal. On the main board I also did some measurements and since the voltage there was a bit under 5v I turned up the power supply a notch, till the multimeter showed 5,14 volts and I measured 5v on the board.

Strange thing is that when I left the cabinet on for a while, I saw very large fluctuations in the voltage I measured on the main board, while the +5v terminal on the switching power supply stayed steady at 5,14 volts. The +5v terminal on the main board varied from 5,00 volts down to 4,30 volts! When the multimeter showed a reading below 4,40 volts, the cab screen went dark and after a while (after the voltage went up again) the machine reset itself and booted up again.

BTW: All ROM's are o.k. at boot up.

[mgb]

Sounds like there maybe a bad chip bogging down the voltage.
Are there socketed chips on that board? If so it may benefit you to first try reseting all socketed chips.
There may even be bad solder joints or another bad component.
Bad caps can cause voltage drops.
Look at the schematics and check the reset circuit too.

[CheffoJeffo]

Nothing new to add, except to note (with some surprise) that I agree with Xiaou2 about the monitor. It is my experience that cocktails (or uprights with monitors mounted on the horizontal and using mirrors) are much worse than other cabs for having degaussing issues when being moved. My Joust cocktail and my Cheyenne always seem to need a degaussing after being moved. A corded drill or soldering gun (not an iron) works fine for manual degaussing, although I have waved magnets very quickly in random patterns when I was without such tools.

The first question I would ask about the voltage on the main board is where you were measuring it -- presuming at the harness, but should ask.

[DeLuSioNal29]

I just checked with a buddy of mine and his T2 machine has a degaussing coil built into the monitor.  It's a big white rubber piece that surrounds the monitor, so check for that to see if you have one or not.

But most likely, in this case, you may have another brand of monitor in there which doesn't have one.  It's worth a shot to look though.

I'll ask if he can chime in to this topic next time I see him and he may be able to shed some light to troubleshooting.

DeLuSioNaL29

[itobandito]

I have a T2 cab as well and have a similiar issue with a corner on my monitor being slightly discolored constantly.  I ended up recapping the monitor and degausing it with a degaussing coil.  When I tested the monitor outside the machine sitting up right, everything looked perfect.  I then popped the monitor back in and the discoloration in the color returned.  I then took the monitor back out sat it up right and no discoloration at all.  This lead me to think it was 1 of 2 problems.  There is something (I don't know what) that is interfereing with the monitor, ie a wire, some sort of magnetic source of some kind or the monitor just doesn't work the way it use to due to it's age.  I checked and I checked, never found anything near the monitor neither outside or inside the cab that can cause it, again though it only would occur when the montior was layed on it's back as it is suppose to in the T2 Cab.

As for your board issue, I beleive I had a similiar problem way back as well.  I removed all rom chips, blew some compressed air in the empty sockets, inspected each chip for bent or dirty legs put everything back in and never had any issues since.  I wouldn't rule out voltage issues though either.  You may want to try buying a new power switcher just to rule it out as they are relatively cheap, plus you'll probably never need another one for that machine as long as you own it.  Other issue could be a short in the cabs harness which would really suck.

[Cenobyte]

I have a T2 cab as well and have a similiar issue with a corner on my monitor being slightly discolored constantly.  I ended up recapping the monitor and degausing it with a degaussing coil.

I tried degaussing the monitor with an electric drill and it helped a little bit. I can't reach the edges of the monitor, so the discoloration is moved outward a bit, but unfortunately still present.

As for your board issue, I beleive I had a similiar problem way back as well.  I removed all rom chips, blew some compressed air in the empty sockets, inspected each chip for bent or dirty legs put everything back in and never had any issues since.  I wouldn't rule out voltage issues though either.  You may want to try buying a new power switcher just to rule it out as they are relatively cheap, plus you'll probably never need another one for that machine as long as you own it.  Other issue could be a short in the cabs harness which would really suck.

I pulled a couple of ic's out and cleaned the sockets and ic legs a bit and did the same with all connectors on the board and the problem seems to have vanished. I played the game almost to the end, measured voltage and got a clean and steady 5 volt on the board. I will test more extensively and will keep an eye on this.

[mgb]

I've used the drill and solder gun trick before and have also found that it works ok but not always great. How about the tv repair guy you mentioned earlier, maybe you can borrow his degaussing coil.