Author Topic: Missle Command Circut Board (Read 6766 times)

RSmith5678 · « **on:** March 20, 2005, 12:46:33 am »

I am trying to get a missile command to work. I think it is the smaller of the 2 circut boards that is bad but I am not sure. did a few tests on it. Replaced R30 10 ohm. (was fried). No power to any of the buttons. blank screen.
ANY IDEAS?

Thanks
RPS

RayB · « **Reply #1 on:** March 20, 2005, 08:33:58 pm »

I just revived a Missile Command cocktail. I'm no expert, but I might recognize some of the symptoms you encounter.

First, can you provide more details on the voltage readings?
The AR-II board should have several test points with several different voltages. Some are DC and some are AC.

Second, your main game board should ALSO have some test points (though some revisions of the board did not). What readings do you get on those? Does the red LED light light up or not.

Let me know what you find and we can go from there.

Since I'm no expert, what I did was a "rebuild kit" on the AR-II board, and also I replaced the "big blue" capacitor on the power-supply. It's an expensive way to solve a problem instead of actually FINDING the specific failed parts, but like I said, I'm no expert, so this way worked.

RSmith5678 · « **Reply #2 on:** March 20, 2005, 11:11:18 pm »

Hey Thanks for replying.
The red light on the PCB does NOT go on. Test points on the Audio board are good on one side 22V+ and 22V- and the 36VAC. on teh other side of the Heat sink I don't get any readings at all. If I unplug the 9 pin and test it I have voltage. When I plug it back in all test points are dead.
Which of teh 4700MF capacatiors did you replace. Mine all look good but that is not a good test. Like i said before I replaced Risistor #30. A 10 ohm clost to the 9 pin socket.
Randy

Wade · « **Reply #3 on:** March 21, 2005, 02:40:52 pm »

I just picked up one of these and it is also dead. I don't have a manual. Are there any available online somewhere?

I would like to troubleshoot this, and at least get my power supply working, before sending the boards off for repair.

Any help is appreciated.

Thanks,
Wade

RayB · « **Reply #4 on:** March 21, 2005, 02:44:59 pm »

OK there can be a couple things going on here. As far as I know, the board won't output the game voltages unless the game board is properly connected. (I don't know why... it sort of "completes the circuit" when the board is connected). Because of this, I found that I could never read the AR-II output without a game board attached.

So I'd suggest you closely inspect your board connector. Make sure the contacts inside are clean and undamaged. Next also clean the board edge traces (that the connector attaches to). Does the first trace have burn marks? Make sure a connection is being made. I clean the traces using a pink eraser.

As far as what capacitors I replaced on the AR-II, I bought a rebuild kit from Bob Roberts. All the major capacitors were replaced (as well as a few transistors). Like I said before, this is not a cheap way to fix one failed part, but the kit involves replacing ALL the parts that commonly fail, and that did fix the board.

~Ray B.

Wade · « **Reply #5 on:** March 21, 2005, 03:55:48 pm »

I will open it up and look at the connector in the next couple of days, maybe tonight.

Do you know of any info on the ARII board, on the net? I can't even test it if I don't know what to look for. Unless of course, everything is labelled clearly and I just haven't opened it up yet to find out.

I might order the kit from Bob for insurance, however I am assuming this will not fix my problem.

Thanks,
Wade

RayB · « **Reply #6 on:** March 21, 2005, 06:05:30 pm »

Wade,
It's pretty obvious once you look at it. There are metal loops with "+10 vdc" and other such writing. You connect one of your multimeter probes to a GRND point and the other to the voltage point you want to test.

Did you get the right board for your machine? There are different revisions.

Wade · « **Reply #7 on:** March 22, 2005, 08:38:49 am »

RayB,

I got to check it out more last night, and found the manual on KLOV.com (forgot they have manuals there until someone else reminded me!) All the voltages I could see tested pretty close. The LED on the board is on, which might tell me something but I haven't had a chance to dig into the manual to find that yet.

I did find this out. Put it in test mode and I got a high beep for the 5th one. According to the manual that is a bad RAM chip. I will try to source one of those and see if that gets it any closer to booting up.

I'm absolultely sure everything (specifically the boards) are original in this game. This and the Moon Patrol came from the same place, and I believe they were together most of their life, judging by the same kind of nasty cigarette tar-dust on everything, and the license stickers. They both have the original monitors judging by the manufacture date and screen burn, too.

Wade

RayB · « **Reply #8 on:** March 22, 2005, 09:36:30 am »

Regarding the voltages, what is "pretty close" in your opinion? If it's just a little too low, that can cause RAM errors (not enough juice getting to all the parts). Your AR-II has a small potentiometer knob to adjust the voltage. For mine, I had to adjust it ALL the way down and it still read +5.4. I feel that's high, but guess what? The game works!

Also you should still clean the connectors to the board so contact is flawless. That will also ensure the juice is flowing fully. And actually, you should do this first before fiddling with the pot.

(PS: Don't fiddle with the AR-II pot with the power on. You wouldn't want to send a voltage spike to the board).

~Ray B.

RayB · « **Reply #9 on:** March 22, 2005, 12:01:23 pm »

PS:
Assuming your connector is snug and clean, and your edge traces are all clean, and assuming you're getting enough juice you need to check the large orange or green things with two legs. Check for broken legs, or even missing ones! I think the board is marked with the letter C and a #. Look at the existing [are they capacitors?] to see what I mean. Then look for similar letter/number combinations where perhaps some have broken off. I know that the board WILL report ram errors during test if any of those (capacitors?) are missing or broken.

Wade · « **Reply #10 on:** March 22, 2005, 12:43:36 pm »

The volts on the AR board were about right, maybe even a hair high. Seems the 5V was around 5.05 or 5.1 on the ARII, and on the CPU board itself I think it was around 4.85. I will have to check these again and write them down, but they seemed "close enough" to me. It occurred to me to turn up the volts just slightly, BUT I saw one blue pot but didn't know for certain that was what it was for. Didn't want to take a chance.

I did check out the edge connector. It seems to be tight and pretty clean, but I went over it with some super fine sand paper anyway, just in case. That top pin WAS burn off, but someone had already cut around the harness and made the connection with a standard quick disconnect (my T&F cocktail has the same hack!)

Since all the voltage points on the CPU checked out close to where they should be, I figured the connector and ARII board are probably working "most of the way". These might show up as intermittent problems later, but for now I'd be happy to get a screen to come up.

I will pull the board out all the way and check it out in more detail, looking for some of those broken legs you talk about.

I am probably going to go ahead and order the RAM, the ARII kit (after I figure out which version I have), and some other random parts from Bob Roberts in the next couple of days.

That'd be nifty if I could get this game working by swapping that RAM chip, or fixing something else.

I just really don't want to spend $85 on a board repair, when I know I'm going to have to spend $70 on sideart and $40 for a CP overlay, plus all the other misc parts to make it nice.

Wade

Rocky · « **Reply #11 on:** March 22, 2005, 03:31:42 pm »

You should adjust the Power supply so you get 5.1vdc on the board. Under 5v is not good.

RayB · « **Reply #12 on:** March 22, 2005, 07:01:44 pm »

Yup Wade, what Rocky said. Why would you order a bunch of parts when your board isn't getting 5v? Like I said, mine reads 5.4. You could replace all the RAM and STILL get errors if they aren't powered correctly.

Try this test: Power on in self-test mode and leave if for a couple minutes, just to see if "warming up" fixes anything. If not, do this next step:

Turn the power off. Adjust the blue pot just a TOUCH clockwise. If you're worried about moving it too much, you can always turn it all the way down (counter clockwise) power on, measure +5 voltage AT THE GAME BOARD. Then turn power OFF. Turn the pot just a tiny bit. Power game on again. Measure +5 again. Keep doing this until you get 5.1 or 5.2.

Once you hit around 5.0 do the self-tests again. Repeat until you are self-testing at 5.2, 5.3 and like I said, mine reads 5.4. Chances are your ram errors may disappear by then.

Wade · « **Reply #13 on:** March 22, 2005, 09:26:04 pm »

Hey guys!

I got a few minutes to mess with it. I upped the voltage gradually up to 5.2 but still no dice. BTW, on my ARII, the blue R8 knob goes counter clockwise to increase the voltage.

I can't wait until I finish up a couple other things I've already started, so I can officially start working on this and the Moon Patrol (which works 100%, but needs repainted and some other new parts). Once this one works, I can justify buying some new parts for it to make it nice. This MC will be much easier since sideart is made for it. Wish it were already done and in my gameroom...

Wade

RayB · « **Reply #14 on:** March 23, 2005, 11:13:14 am »

COUNTERCLOCKWISE!?

AAACK!
crappers. That means I have mine turned all the way up.
I told ya I was no expert! HAhahah

I'm gonna go turn it down now. Sheeeee-it!

Wade · « **Reply #15 on:** March 23, 2005, 11:33:27 am »

Heheheheh!!

Well at least you didn't fry anything! Could have been worse.

I still haven't had a chance to check out all those caps. Maybe tonight!

Wade

Wade · « **Reply #16 on:** March 30, 2005, 08:52:00 am »

Good news!

My parts arrived Saturday from Bob Roberts. I didn't install the ARII rebuild kit since at this point, it didn't appear to be needed.

I soldered in a new RAM chip in place of the bad one (WOW, that was TOUGH... so tiny!), and the game works 100%! I didn't know if the monitor even worked, but it's picture is quite good actually. The blue is a bit fuzzy, but I figure a cap kit will solve that. We'll see. The tube has some burn, but it is where the mountains are (which never change), so it isn't noticable with the game on.

I'm happy! Now to fix this thing up!

I'm keeping my fingers crossed that it keeps running for awhile. Oh, I also threw the boards in the dishwasher because I was getting so dirty trying to work on them. Came out looking great... I will probably throw the whole harness in there next, plus the monitor chassis and whatever else I can fit in there.

TTYL and thanks for the help!
Wade

Rocky · « **Reply #17 on:** March 30, 2005, 11:00:08 am »

Wade,

When you replaced the Ram chip did you solder it in directly or use a socket.

Wade · « **Reply #18 on:** March 30, 2005, 11:27:49 am »

No, I didn't use sockets, against everyone's suggestion. I bought 10 chips and 8 sockets with the intention of replacing all with sockets. Easier said than done! It was impossible for me to solder the sockets on to the board. There was simply no room to fit the tip of the iron! I even bought the smallest tip i could find and filed it down even sharper.

I ended up soldering the chip directly because it was the only way I could get it to work. If I have another chip fail, I will try soldering a socket again, since I might have a little better luck.

Hopefully, it will just keep working so I don't have to deal with it at all. But I figure it will break again sooner or later. Maybe I'll have more experience or have the right tools the next time.

TTYL,
Wade

RayB · « **Reply #19 on:** March 30, 2005, 02:55:17 pm »

No room for the soldering iron tip?? You mean between the top of the circuit board and the plastic of the socket?

*cough* ...umm...

Did you consider soldering the BACK side of the board where the legs stick out?

Wade · « **Reply #20 on:** March 30, 2005, 03:43:12 pm »

Don't razz me too hard, I was proud that I finally fixed something... even if it IS jacklegged...

Yeah, but there were tiny traces on both the top and the bottom of the board, depending on the pins. Most were on the top. I was afraid the solder wouldn't make contact. Maybe those concerns were unnecessary. Also, I had a couple of traces were the metal got torn off when I removed the chip. This made the problem even worse (the blob of solder likely wouldn't reach the trace on it's own).

If I have to replace another RAM chip, I will try the socket again. I just didn't see how I could solder one of those sockets in there. Looked impossible to me. Maybe I was just intimidated by the size. I have soldered lots, but I have never soldered something so tiny and so hard to see. I will also try a lot harder not to damage the traces when removing the old chip.

TTYL,
Wade

RayB · « **Reply #21 on:** March 30, 2005, 05:45:53 pm »

OH it was one of those tiny chips? Sorry, I was thinking about the big EPROMs.
Yeah, I understand your hesitation now.

Wade · « **Reply #22 on:** April 27, 2005, 01:32:45 pm »

Okay, I'm back to square one. Actually, I'm back further than that!

After my MC restoration, it isn't working any more. Test mode gives static, then a deep and then a high beep, which I think indicates everything is fine. However, the game won't start up. I just get a dark blue screen, and some garbage if I hit buttons, roll the ball, etc.

I went ahead and installed the Bob Roberts AR2 rebuild kit. Install went fine, didn't fix the problem (I double checked the 5V and 12V afterwards and dialed in the 5V). The 12V is about 11.8 or so, which is what it was before the AR2 rebuild, too. Is there a way to adjust the 12V? How low is too low?

What's the next step? Double check all voltages on the AR2 again, and test for continuity from the edge connector to the harness?

Thanks,
Wade

RayB · « **Reply #23 on:** April 27, 2005, 02:29:22 pm »

11.8 is fine. It's used for audio anyways (AFAIK)

When you say the game won't start up, is this with the test mode switch on or off? (just asking in case you had a blonde moment and didn't switch it off)

Wade · « **Reply #24 on:** April 27, 2005, 02:35:09 pm »

This is with the switch off. When it is on, I get the static, a low beep then a high beep, which if I'm understanding the manual correctly, means everything is a-okay.

Wade

RayB · « **Reply #25 on:** April 27, 2005, 06:27:26 pm »

Yeah, and after the "a-ok" beeps, you should have a screen with the cursor and some info... sounds like you don't get that?

Wade · « **Reply #26 on:** April 27, 2005, 09:08:12 pm »

Sure don't.

Wade

RayB · « **Reply #27 on:** April 28, 2005, 12:34:29 am »

Well the thing is, the self-test tests what, 8 chips? Yet there are many more than 8 on the board. Could be bad EPROMs or other...

Wade · « **Reply #28 on:** April 28, 2005, 08:26:33 am »

Yeah, I think the self test just tests the RAMs, but I'm not positive. Guess I'm going to have to get someone to walk me through an involved troubleshooting session. I'm leaving for the Allentown pinball show tomorrow morning so I'll have to pick up on this next week.

TTYL!
Wade

Wade · « **Reply #29 on:** May 03, 2005, 02:18:41 pm »

Okay guys, does anyone have any more recommendations for things I could test? I will recheck all the voltages, but I'd be willing to bet they are all just fine (were before the rebuild kit... probably are now, after it too).

Thanks,
Wade

RayB · « **Reply #30 on:** May 04, 2005, 11:24:54 am »

I guess I would replace the EPROMS?

Wade · « **Reply #31 on:** May 04, 2005, 11:34:47 am »

Hmmm, yeah, worth a try. I don't know anyone offhand who can make them though.

Wade

Wade · « **Reply #32 on:** May 09, 2005, 12:54:50 pm »

RayB,

I reseated the chips and all the voltages are good.

What should I try now? Find someone who makes EEPROMS?

Also. There are two connectors on the harness right at the coin door that I can't figure out what they connect to. They are two tiny quick disconnect female spade connectors. I can't find anything for them to connect to. I'd just like to verify they aren't supposed to connect to anything.

Wade

RayB · « **Reply #33 on:** May 09, 2005, 02:05:17 pm »

Spade connectors? Sounds like the ground line that's supposed to tie all metal parts together.

But I can't say for sure that's what they are.

As for the PROMs, there are services out there, but I don't know them off-hand. RGVAC is probably your best bet at this point.

Wade · « **Reply #34 on:** May 25, 2005, 08:41:12 am »

I'm still not sure what those two connectors are for. They don't look like a ground. One is a white wire and the other is a black wire. They are right inside the coin door next to the volume control. Maybe I will snap a picture of them.

I just wanted to post a follow up for this thread. Last night, I removed all the chips and sanded them with some fine sandpaper. They didn't appear very dirty at all, but I didn't know what else to try short of sending it out for repair. Well, it worked!! DEFEND CITIES!!!

Wade

Rocky · « **Reply #35 on:** May 25, 2005, 09:10:50 am »

Wade,

That's great.

Wade · « **Reply #36 on:** May 25, 2005, 09:40:06 am »

Yeah, I wasn't sure either. In fact, I was pretty sure I WASN'T going to get it working.

I had tried reseating the chips already. Cleaning them with sandpaper was my "last ditch" effort. I didn't expect it to help and was really surprised when it did. I don't know that the sanding made a difference, it could just be that I didn't have them seated straight from the last time, or something else like that.

Relieved...

Thanks for the help guys! Saved me $100 dollars or more!

Wade

RayB · « **Reply #37 on:** May 25, 2005, 10:59:22 am »

Does your machine have a coin counter? If not, maybe that black and white wire is for powering the coin counter.

In any case, it works now. Just tape up those loose wires so they don't accidentally touching something else and short-out something.

Wade · « **Reply #38 on:** May 25, 2005, 11:20:27 am »

Yeah, it has two counters, one for each slot, and they are powered through a big harness connector along with the other coin door stuff. At first I thought it might be for the volume control but it is hooked up and works.

I'll get some pics and then just tape them up. I suspect it is a factory omission.

Wade

RayB · « **Reply #39 on:** May 25, 2005, 01:48:16 pm »

Do you still have a slam switch?
Does your coin door have lights?


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