I'm working on a Stern Magic. About half of the feature lights are not working. For example the High Score light is out. If I connect to ground it lights. No light when connected to the driver board. I connected a jumper from J2 - pin 23, still no light. I did the same for Game Over (J2 - pin 11) - no light. Those two lights are from two different decoders (U2 and U3).

I suspect the problem is in the lamp address or lamp data connectors from the MPU. How can I test these inputs?

All the connector headers and crimp connectors are new but I've found 3 bad connectors already. (in the displays and the switch matrix)

Thanks

Bob

I just discovered something. 4 of the lights that are out in the back-box are Ball in Play, High Score, Game Over, and Tilt. These connect to U1 - pin 14, U2 - pin 14, U3 pin 14 and U4 pin 14.

Then I looked at the other lights that are out - Player 1 Up, Player 2 Up, Player 3 Up and Player 4 Up. These all connect to pin 16 on each of the decoders.

I haven't looked at the playfield lights that are out yet but I suspect I'll find the same kind of pattern.

What would keep those pins from lighting?

Thanks

Bob

Thanks Quench,

This is exactly the information I needed.

I probed pin 2 on each decoder and got high-low and pulse. Then checked pin 3 on each and got high only. Then pins 21 and 22 and got high-low and pulse.

Looks like pin 3 (AD1) is bad.

I then checked R71 on the MPU (AD1) and got high-low and pulse.

Looks like a problem with MPU J1 - pin 14 or Light driver J4 - pin 15.

I seem to be having a lot of problems lately with connectors going flat. It could be the that I'm smashing the connector when I install them or the connectors are loosing their springiness. But to be sure I ordered some new connectors from GPE. When they come in then I'll change these connectors.

Is there any way you could tell me what other lights (or SCR's) would be effected by AD1 not working? I have about 20 lights on the playfield not working as well.

Thanks

Bob

WOW. That's like looking at a list of lights that are out on my game. When I started working on the lights I was making a list. I quickly realized the list was going to be too long so I just stuck a piece of blue tape on the bad light inserts. Check the photos. Looks just like your list.

I'm trying to understand the information above. I'm vaguely familiar with binary numbers. Back in the late 70's we had one of the first CAD computers where I worked - about the size of 3 refrigerators and a whopping 32 megabytes of memory. I helped do some programing on it. But that WAS a couple of years ago.

Hopefully the new connectors will be here tomorrow or Friday and I'll get this thing all finished.

Thanks Quench.

Bob

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1970's computer

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New connectors arrived today. I replaced the offending connectors and now most of the lights are working. Only about 5 - 6 lights out but I think those are bad sockets. Repair/replace a few sockets and this game is good to go.

This game sat neglected for years. The playfield is almost perfect - no wear at all. It's been a long trip but now it's going to be a nice player.

Thanks for all your help.

Bob