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Hot Hand / Student prince power up

darren_ross

darren_ross

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Joined
Jan 12, 2015
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Stockholm, Sweden
After having a bit of a rummage around in the garage of the apartment I live in. I've come across a couple of pinball machines. After speaking to the landlord, I have permission to set them up. They look like they'e been stood here for at least 20 years.

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Anyway now one of them is set up. The thing doesn' boot up. Lights, but nothing else.
The fuses have been checked but what's worrying is the rectifier board. Every wire has been soldered on by the look of it. Seems like some nasty repairs and corrosion on there too.
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I don't really want to put any money into it as it's not mine, nor does the landlord care about it to be fair. Would just be nice to see it working.
I really don't know much about these old sterns. I've done a little googling but that's it.
Any pointers on this thing would be muchly appreciated.

Darren
 
Schematic will help, it has the rectifier board layout - 2nd diagram:
http://mirror2.ipdb.org/files/1244/Stern_1979_Hot_Hand_Schematic.pdf
You can use that to check the voltages and the wiring to the correct pins. As you will see from the schematic, a lot of the pins and wires are actually connected together (e.g. a lot of earth wires). Should be easy to test out with a meter. You have the 5 test points TP1 - TP5 at the top

BE VERY CAREFUL one of those is high Voltage DC current on TP2
 
Hi, Darren,

The electronic side of the old Stern games is basically the Bally system of the time, except for 'audio', which is an expansion board added to the Mpu, rather than a separate processor, Rom, etc.

I've always thought that that motorised 'sweeper' at the top of the playfield was included to use up left-over parts from Chicago Coin's attempt to introduce 5" flippers several years earlier
 
So you powered it on without disconnecting all the boards?
 
I just needed to do one solder and re-seat all the plugs. Always first step to re-seat I guess. Why would i power it on after disconnecting the boards?
I could do with shopping my pinball tools across from the UK to be fair :oops:
 
So you don't send god knows how many volts thru any mpu/driver boards?
 
So as a precautionary measure one always disconnects any cables attached to the mpu/driver board etc before powering on an old beast like this. Then takes readings from the rectifier board to ascertain what voltages are being sent out.
 
Arv said:
So as a precautionary measure one always disconnects any cables attached to the mpu/driver board etc before powering on an old beast like this. Then takes readings from the rectifier board to ascertain what voltages are being sent out.
Click to expand...
Ahh I see. Never did I know. Now I do. Thanks mate. Glad the thing isn't in bits.
I will do this before I power up the 1969 beast
 
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So i got round to dragging this old gal out tonight.

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A bit of a mess at first glance. A little glass cleaner later

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Looks like some kind of hard resin has been spilt right down the glass. Going to take a little more polishing to get that baby off. But it can wait for now.
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Backbox was found slung in the corner. No sign of the legs or bolts though
 
Razor blade at an angle should get that resin off watch your eyes though for bit flying off. Wear goggles.
 
Looks to be in really good shape cosmetically :thumbs: It's obviously not been used for a while judging by that first pic :rofl:
 
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So it's together. Great fun lifting that back box up on my own.
Turned it on, but nothing much is happening. Fuses are fine. I just get a light buzzing and a coil next to a coin mechanism is firing
 

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Hi, Darren,

Williams and Bally e/m games usually have contacts on the left flipper button, simply to energise a 'Hold' relay and bring the machine into the Game Over mode

The small coil on the coin door is the 'coin lockout' - without this energised even the correct coin(s) will be rejected
 
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