switching power install

71CutlassS

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Im wondering how to install a switcher in an uncommon game. I dont have a manual/schematic and I doubt theres one online, but I do have the fried ps board. Is there a site with step by step instructions or anything?

This games been sitting in my garage for about a year and Id like to get it up and running one day! I think its the only issue with it too.
 
What game is it ?

Your average everyday run-of-the-mill this:

Picture463.jpg
 
I remember those cabinets. These were conversion cabinets.

From what I remember they had a phony baloney power supply. I _think_ that I converted one to a switching power supply years ago.
 
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This is the same cab as my frogger. If its a conversion, then a lot of trouble was gone through to put white vinyl on the entire cabinet!

It is also on their promo flyers and such.
 
This is the same cab as my frogger. If its a conversion, then a lot of trouble was gone through to put white vinyl on the entire cabinet!

It is also on their promo flyers and such.

Continuity check for ground and +5 from an eprom? Best I can think of... But if it uses -5 and 12V(which it will...) I'm not sure about checking for those besides running through the schematics and finding points that you know will be +12.

I'm surprised the schematic doesn't have the wire colors and values listed... very weird.

EDIT: You said you don't have the schematic... misread that, sorry.
 
Connector by the LED's is the DC output to the game board. The other connector is the low voltage AC from the power transformer.

Looks like it puts out the standard video game voltages, +5, +12, and -5 volts.

You should be able to flip the power supply board over and trace the +5 volt LED to the +5 volt output pins on that connector. Likewise with the +12 and -5 volt LED's. The other remaining pins are probably ground.
 
Connector by the LED's is the DC output to the game board. The other connector is the low voltage AC from the power transformer.

Looks like it puts out the standard video game voltages, +5, +12, and -5 volts.

You should be able to flip the power supply board over and trace the +5 volt LED to the +5 volt output pins on that connector. Likewise with the +12 and -5 volt LED's. The other remaining pins are probably ground.


If that black line (left) is ground... which it looks like since its connected to what I would think would be the large ground plane... then that 1000uf cap looks like it's on backwards while the 4700uf appears to be correct... Then again, it could just be that I'm really tired... no idea.

Just shoving the wired (+5, +12, -5) under the fuses (on the connector end) should give the right voltages out to where they need to be. Quick way to test the board, then after that just trace those wires closer to the board and splice in the voltages where they need to go?
 
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OK basic question, what exactly is the process that a switcher performs? Does it take 120v and turn it to the -5 +5 +12 internally?
 
All power supplies will take wall voltge and step it down to the desired voltages. Some do it by stepping the voltage down in stages and running taps off for the various voltages. Some actually have multiple power supply sections that just tap off of the original voltage.

Without seeing the values of the components, the original PS is a linear PS that takes the AC voltage (probably already stepped down to 12VAC) runs it through a half wave rectifier circuit (the two big diodes) and smooths it with the two big caps. That voltage, probably nominally 12VDC looks like it is being fed into the two voltage regulators (Q1 & Q2) to produce the +5 VDC and -5VDC. If you were so inclined, all of those parts should be readily avaiilable. It wouldn't be hard to rebuilt that whole board.

Or just trace the lines from the fuses and make a matching harness from a molex header and some wires over to the switcher.

ken
 
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