Sanyo EZ-20 100v Power Question (Solved)

[Titan91]

I installed a cap kit in my Sanyo EZ-20 Donkey Kong monitor. The monitor was working before after it warmed up. Before warm up it would lose horizontal sync. The AC outlet in the bottom of the cabinet is putting out 110v. The sticker says "100V MAX." I have 122v at the wall outlet.

I don't want to power up the monitor unless I know it's safe to do so with 110v going in to it. As the monitor was working before at 110v, will this be ok to leave long term? I'm going to sell this and don't want to stress the monitor, causing issues down the road for the buyer.

The line input is connected to the 120v spot on the main transformer. The transformer and cabinet wiring all look original and unhacked.

 

[behrmr]

You can't plug a Sanyo into a wall outlet you will blow it up. It needs to be through an isolation transformer and it needs to be 100v. In most Nintendo cabinets there is what looks like an outlet where the monitor and the marquee plug in. That outlet is stepped down from the wall to 100vac and is isolated.

 

[Titan91]

Correct. But in my case I'm getting 110v. I read a few places on here that 105v is the absolute max. So I think I have a bad isolation transformer. Looking at the schematics, there are two 100v secondary windings. One for the game board power supply and another for the monitor and marquee light.

I'll need to find an isolation transformer that handles a 118w load at 100v.

 

[jimbodeanny]

Both of the transformers in my Punch-Out and Red Tent measure roughly 105-106vac coming out of the outlets on the isolation transformers. I think it's pretty common for them to pump out a little more than 100v. 110 sounds a little high though.

 

[Titan91]

Yeah I think the isolation transformer is bad. The primary is wired to 120v correctly on the block. That secondary winding that powers the monitor and marquee probably has some fused turns. Curiously enough, the marquee light has been completely removed from this cabinet. I'm thinking the transformer probably got hit by a lightning strike or power surge, causing it to step up the 100v output to 110v. This in turn probably caused the 100v marquee light to blow starters or lamps, which is why it was removed. Just a theory.

Where's the best place to find a replacement PT821B transformer? I checked eBay which is has only one result for a non-working power supply assembly. Would a typical Japanese 120v to 100v step down one work as long as it handles 1.2A on the output, per the label on the cabinet sockets? I found one that outputs 300w.

 

[security0001]

Yeah I think the isolation transformer is bad. The primary is wired to 120v correctly on the block. That secondary winding that powers the monitor and marquee probably has some fused turns. Curiously enough, the marquee light has been completely removed from this cabinet. I'm thinking the transformer probably got hit by a lightning strike or power surge, causing it to step up the 100v output to 110v. This in turn probably caused the 100v marquee light to blow starters or lamps, which is why it was removed. Just a theory.

Where's the best place to find a replacement PT821B transformer? I checked eBay which is has only one result for a non-working power supply assembly. Would a typical Japanese 120v to 100v step down one work as long as it handles 1.2A on the output, per the label on the cabinet sockets? I found one that outputs 300w.

here is a 100v iso transformer.

Monitor Isolation Transformer 100V Output - Arcade Parts and Repair

Arcade CRT monitor isolation transformer with 100VAC output and 120VAC input 60Hz, 100VA. color coded wires for the input & output for easy installation.

www.arcadepartsandrepair.com

BTW: if your transformer has no load on it when your measuring it then the 110v is probably okay.

 

[Titan91]

Thanks! That's what I'm missing. I was testing the output with nothing plugged in. Let me test it again with a 100w light bulb connected to simulate that load and I'll report back.

 

[Route3]

here is a 100v iso transformer.

Monitor Isolation Transformer 100V Output - Arcade Parts and Repair

Arcade CRT monitor isolation transformer with 100VAC output and 120VAC input 60Hz, 100VA. color coded wires for the input & output for easy installation.

www.arcadepartsandrepair.com

BTW: if your transformer has no load on it when your measuring it then the 110v is probably okay.

I'm having similar issues. And how compatible is this ISO to the original. The unmodified AC tap that ran into the original PP-7B are a dead end. And to the power block is the input on this transformer 0V and 120V, thanks Jeff

 

[security0001]

I'm having similar issues. And how compatible is this ISO to the original. The unmodified AC tap that ran into the original PP-7B are a dead end. And to the power block is the input on this transformer 0V and 120V, thanks Jeff

it can replace the original 100vac iso transformer. your input is 120vac and the output is the 100vac that you need for the nintendo cabinets.

 

[Route3]

I appreciate your response. I'm so new at this and trying to not go crazy figuring it out, this is my current set up which I think is incorrect, since I went with a switching power supply