Medieval Madness Slam tilt switch is stuck closed

[andrej]

Relative newbie to the forum and not technically minded so bear with me.

My MM is telling me that the "Tilt switch is stuck closed". I'm looking through the operating manual and can't quite work out what I need to do, or even where the tilt switch is.

Can anyone help me with some Pinball repair for dummies advice?

[Crashramp]

Relative newbie to the forum and not technically minded so bear with me.

My MM is telling me that the "Tilt switch is stuck closed". I'm looking through the operating manual and can't quite work out what I need to do, or even where the tilt switch is.

Can anyone help me with some Pinball repair for dummies advice?

Hi mate,
You can find the location of the switch your looking for in the manual on page 2-48. If you don't have a manual you can download it here under "documentation" http://www.ipdb.org/machine.cgi?id=4032

[Crashramp]

Also see page 2-3 in section 2 of the manual.

[andrej]

Thanks and found it. On page2-3 it shows item no 14 as Tilt mechanism assembly. I've had a look at it and can see a green and white wire connected top and bottom. Both look good.

I guess I am not actually looking for a switch? Is this something I can reset or fix?

[pinsanity]

Is it tilt switch or slam tilt switch?

One is like crashramp said with the hanging plum bob and the other two are attached to the back of the coin door and the floor of the cabinet.

It will look similar to this - this is not from a Medieval Madness but will closely resemble the picture



Check to see if one or the other has a bent metal tang and is permanently touching which could be a cause of the slam tilt message.

All three metal tangs in the assembly should be separated and not touching like the picture above - you can manually bend them to separate if they are.

If you are still stuck I can grab a picture from my MM showing the locations of where you need to look.

[andrej]

Yes its the slam tilt switch. looks fine to me?? Sorry my pic uploaded upside down.

Sent pic again

[pinsanity]

Check the one on the back of the coin door as well.

This is just the preliminary to eliminate any obvious causes.

[andrej]

This bit on the back of the coin door looks ok?

[pinsanity]

Okay so the problem lies further up the line. It will probably be a wiring short related to the slam tilt or a problem with the CPU board itself.

[pinnies4me]

Not at home to check, but if they are connected via a connector you can disconnect, might be worth disconnecting one at a time first to see if that eliminates the issue. have game off, disconnect, turn on and check. If it does, then the switch that is disconnected is the issue, if not, as Pinsanity said, then it may be on a board.

[Homepin]

Seems as though your switches are all OK.

Have you done any work on the machine recently? Changed lamps for LEDs etc? Adjusted something under the playfield?

Below shows a portion of the switch matrix for MM - we can see from that you have the Slam Tilt as switch #21 and the Plumb Bob Tilt as switch #14.

The ST connects to the MPU board at connectors J206 pin 2 and J205 pin 1

The PBT connects via J206 pin 1 and J205 pin 4

The common factor here is that (as the diagram also shows) both tilt switches connect to IC #U20 - this is VERY WELL KNOWN as a failure point when people have been "playing around" under the playfield. (It also shows connection to IC U17 but this is a rare failure point unless you have tried very hard to damage it  )

You should (power switched OFF) unplug connector J206 from the MPU and turn on - if your Tilt warning remains you can bet IC U20 is knackered!

[andrej]

I haven't touched the machine for a long time, changed the occasional globe but that's all.

Fantastic advice and appreciate your excellent direction....I will attempt?? to check the MPU board.

[robm]

Yep check the mpu. My money is on u20 being the culprit

[andrej]

Homepin, thanks for your advice and I think i have done what you suggested.

I assume the MPU is the one behind the backscreen as shown here. I disconnected J205 and J206 pins, turned the machine back on and it made no difference.

Are you telling me I need to replace this whole board? IC U 20 is fixed in this board, so I guess that can't be replaced.

Is there any other way to test this, my brother is an electrician, are there any tests he could do?

Thanks for all your help so far.

[robm]

U20 is a ULN2803 chip. If you have not had soldering experience, its probably not a good repair to start on!

If you (or someone you know), knows how to solder, cut the legs off U20 on the board, then desolder the remaining stumps left of the legs and clean the holes out.

Put a socket in place, so that if you need to replace it in the future, you can do it without soldering.

Socket and replacement U20 can be found at Jaycar or other electronics shops

Make sure you change the batteries, and mount them off the board - if they leak, you will be up for more expensive repairs