How to tell if I need an Isolation Transformer

[Chainsaw]

Hello. I have a Capcom Q25 cabinet that I've been restoring and looking to turn in to a MAME cabinet. When I purchased the cab it was complete, missing only a PCB.

I stripped the cab out and haven't put anything back. Living in the UK I thought I could simply plug the monitor in to a 220v-110v stepdown transformer and that would be fine. I've connected the monitor to a 300w transformer, and run a seperate wire for Ground in to the wall socket, so that should be taken care of.

Then I rad a little and start hearing about Isolation Transformers. So my question is, how can I tell if I need one and if the PSU I took out of the machine is one or not? It has a model number "CPS-001A-7A" but I've been unable to find any documentation about this or the cab anywhere online. Here is a picture of the PSU:



Other pictures of the cab can be found here:

http://www.chainsaw-films.com/games/arcade/index.html

Many thanks in advance, I don't want to carry on until I know what I'm doing as it sounds like I could kill myself!

Thanks,

Matt
http://www.chainsaw-films.com

[nwhutt]

Did your monitor originally plug into the PSU in the picture?

If it did it looks like it runs off 100v and needs an isolation transformer.  You have a very expensive to replace Nanao monitor in there, looks like it could be a dual res one as well don't plug it directly into the mains or put more than 100v into it.  As a) you will probably blow it up and b) without an isolation transformer the whole chassis will be live and you are likely to electrocute yourself.

Anyway I don't see why you would need to remove the original PSU???  Just put an Arcade VGA card in the PC and connect to a JPAC, plug this straight into the jamma harness and the job is done.  No need to rip the cab to bits and it's all easily undoable if you want to play a real gameboard or sell the cab at a later date.  It just seems like you are making more work for yourself.

Regards

Nick

[Chainsaw]

Thanks man. I tok everything apart as the cab had been languishing in a Japanese arcade for many years, and the condition inside was scary  So much gunk and dirt, it needed stripping to be cleaned. And not knowing any better I thought the PSU was to supply everything and all the monitor needed was a stepdown.

Now I know, I can't thank you enough for taking the time to help me out.

Matt

[Thenasty]

well when you get your stuff together, it does not matter if you use an ISO even if the monitor don't need one. It won't hurt the monitor to use an ISO, in fact it might help the monitor.

[Chainsaw]

Thanks guys. I'm now counting myself lucky I didn't d any damage to myself or the cab, and that I decided to ask just in case.

With a bit of luck I'll get everything up and running within the next week or two,

Thanks again,

Matt