Sigma SG 150 double cherries, transformer needed KS-1503A 120v to 100v

[Skyape]

I’m in need of a transformer for a Sigma SG150. It’s a KS-1503A 100v. I would greatly appreciate any help in locating one.

[Chris-socal]

Is that the little one up by the switching power supplies?
If so, thats a 24v ac transformer. Nothing special about it really, it goes to the game board and gets rectified if I recall correctly.
How did one of those die? Did it get shorted?

Chris

[Skyape]

The transformer is the one on the plate that holds the three power supplies (5/12/24v). I’m also replacing all three due to two are bad. (The 5v and 12v have issues).

The output voltage on the KS-1503a is <16vac. I assume that the output voltage on this one is 100 V due to the markings.

Here’s what I found online…
The model number "KS-1503A" is not a standard designation for a power transformer and is likely a proprietary part number for a specific piece of equipment. Information about a 100V transformer under this model is likely referring to a component inside a device made for the Japanese market, which operates on 100V AC power.

[Chris-socal]

I don’t think so, 100v is the standard AC voltage in Japan, where these are made. Most of their equipment has no problem running in our 120vac world.
The schematic will tell you the output, it might rated at be 14vac but because its a transformer it is directly proportional to the input. That power goes to the main board, the wires on the left of the white connector….brown if I recall. It does not output 100v.
Unless you have a version of machine Im not familiar with, I really don’t think that is the problem. The switching power supplies are likely your problem. I have worked on many and I have never seen the little transformer fail.

Chris

[Skyape]

Thank you so much for the info. I’ll wait on the new power supplies and see if I have anymore issues with power.

[Chris-socal]

Those switching power supplies are known to have leaky caps but you have to open them and remove the board to see the damage, even though they are upside down. The 2200uf and 1000uf caps are notorious for going bad. Their voltage will drift significantly, possibly starting low, then edging up well above the stated voltage, then as they get hot they drop below what the components, like BV, like and the machine starts acting up.
If you had trouble once it isn’t going to get better.
You can replace them with any switching power supply of similar rating but unless you get Eiko the AC input screws will be on the opposite side and you will need to un-do the wire loom and move the wires around. Some wires might be too short so you might have to extend them, depends on your machine.

Chris