Help with power distribution board for kyoraku kamen rider machine.

[rugdoctor]

I think the IC kicked the bucket once I powered up after the initial short of the original step down failure. The machine was used properly prior to purchase. The transformer in the machine has no markings at all, but produce the steady voltage of 27AC when plugged into the new stepdown. When I powered up the second time the machine lit up and was normal then I notice a small puff of smoke. That is when I searched for the source of the problem.

[rugdoctor]

The replacement stepdown I used was rated for 500w. The original one suppose to handle up to 200w.

[daverob]

What's the spec of the step-down? I assume it's a 230 to 100v unit and the transformer fitted to the pachi is the original 100v to 24v as fitted in Japan.

Is the step-down transformer a wound iron core transformer or an electronic unit? Post pictures if you're not sure.

[rugdoctor]

the pachi has the wound up one screwed on the bottom of the machine. The lead coming out from it is a standard japanese 110V plug (it does not have any labels or marking). This is the step down I used for the 240-110V conversion.

344702482.jpg

* Convert from 240V to 110V
* Rated power: 500w
* Input voltage: AC 240V with fuse protector
* Output Voltage: AC 110V
* 2 x 110V output stockets
* On / Off switch
* LED power on light
* Fully Earthed SAA approved Plug
* CE certificate
* Colour: Black
* Dimension: 12x15x10 cm

**Caution, for safety reasons, ensure that any appliance you connect to this transformer does not exceed 350W

[daverob]

It's difficult to tell what type of step down converter that is from the pictures/spec.


I'd always recommend removing the Japanese transformer and replacing it with a locally sourced 24v transformer for the countries with 220-240Vac mains supplies. The reason is that if you use an electronic stepdown their 110V output waveform is often not a pure sine wave, and so is not suitable for inductive loads (such as the Japanese fitted 100V-24V transformer).

The cheapest electronic stepdowns have square wave outputs, and if this is fed into a wound transformer you get huge spikes on the output which can cause this sort of damage to the pachinko machines power supply board. If the converter is specced as 'Modified Sine Wave', then it's usually a square wave output, the only electronic converters that are safe to use are the 'Pure Sine Wave' type, but I'd still prefer to see a replacement 24V transformer used instead.

If both step downs are not of this type, and use large wound transformers instead of electronic converters, then the above does not apply, and we need to find another cause for why the power supply IC has been damaged. If the original 200W one was electronic, then it may have stressed the electronics on the pachinkos power supply board which caused the eventual failure.

The switch mode power supply IC appears to be a common type, so it should be possible to find a replacement, but I'd carefully inspect all the components around it for signs of damage, as often in these cases it won't be just the one obvious failure. It'll also be a tricky one to remove as the tab is soldered to the PCB, you'll need to snip each of the legs with good quality side cutters and unsolder and remove them one at a time to avoid stress on the PCB tracks, before attempting to unsolder the tab. Then clean up the traces using solder wick before fitting the replacement.

[rugdoctor]

Will tread with care. Inside the stepdown is an electronic transformer, will ask the seller about the waveform. Currently in negotiation with the seller of the pachi whether I can buy his transformer off him and another machine. He claim the transformer he has can power 3 machines simultaneously.

[rugdoctor]

I received the diodes, they are bigger than the original blown one, its bidirectional so it can be soldered in either direction right?

[Tink]

Correct, not polarity sensitive.