Changing a power supply

Acid King · Post by **Acid King** » Wed Apr 11, 2007 4:16 pm

I'm looking to swap out my power supply this weekend (Yeah, I know it's been 5 months since I got it... that's five months a mint Galuda 2 has been sitting on a shelf unplayed...). Does anyone have a diagram of the wiring for a cabinet handy? The plan is to mount the new supply in the back, run all the wires for power through that and leave the other supply in unattached except for the volume, test, demag etc functions that are mounted on it. The wiring inside is a bit of a clusterfuck so I wanted to find a diagram of the wiring if possible.

bay · Post by **bay** » Wed Apr 11, 2007 9:45 pm

not all cabinets are created equal.

Post by **Dave_K.** » Wed Apr 11, 2007 10:42 pm

As bay mentions, power supplies can vary widely. If its a standard Astro City supply, then look at the last two pages here for a wiring diagram (and verify with a multimeter): http://www.killercabs.com/manuals/snac.pdf

Acid King · Post by **Acid King** » Thu Apr 12, 2007 12:00 pm

The plan is to replace this 7a power supply with this 15a power supply. The cab is a new astro city.

Post by **system11** » Thu Apr 12, 2007 12:51 pm

That's going to be awesome fun.

See Dave's link, you need to pick just the wires needed for your new supply, cut them off from the connector(s), and route them to the new supply. At a glance, that's the +12,+5,-5,GND lines. HOWEVER. You'll need to leave valid ground on that connector too or the test/etc switches won't work. I'd suggest leaving one GND connected between that connector block and the PCB, and allowing the PCB to essentially provide the ground line. Now, this means inside that power supply/etc block, you'll still also have the ground connected to ground of the faulty PSU - so you'll need to turn it upside down/take it apart/whatever, and remove the feed beween the old PSU outputs and the common bar (at a guess) used at the connector outputs. It's probably worth gutting the PSU box anyway, you really don't want anything going in or out of that anymore.

Now the AC side is more fun. You need to leave 100v going in there, because it's the output for your light fixture and monitor. If you don't do this, youll need to splice the three or so pairs of wires together, cutting all from the larger connector except for the demag button wires. Now, the cleanest way to do this (if that diagram is correct), would appear to be to steal the output pair 4,6 on CN1 and route those to the new PSU, because it appears to go nowhere. It's likely that the CN1 inputs and outputs use some common bars inside the PSU block, and if you've fully removed the old PSU guts, those common links will be safe to use. This can be checked by gutting the PSU and checking continuity between the input and output pairs. Test this with the connector between CN1 and the transformer disconnected. As for field ground, it's probably best to run another from the same source as the one going into the PSU.

Enjoy.

Personally I'd source a proper replacement, it could turn into a real hackjob in there unless you're intending to make a good clean job of it. Connector blocks are your friends.

Acid King · Post by **Acid King** » Thu Apr 12, 2007 1:41 pm

I'd like to get a proper replacement for it since my technical skills are, shall we say... fucking shit. I don't know what the likelihood of finding one is though. If you know offhand where I could get a larger, similar styled PSU, or even somewhere I could begin to look, let me know and I'll just hold on to that other one, maybe use it for a supergun project or something. I emailed Matsu and he said he didn't know about it. I think something might have been lost in translation though. Maybe I'll try to get in touch with him again and see what he thinks.

Post by **system11** » Thu Apr 12, 2007 1:57 pm

Suggest posting a WTB in the trade section for one, hopefully someone who knows where you can get Sega parts in the US, can help. If you lived in the UK I'd know where to start.

Acid King · Post by **Acid King** » Thu Apr 12, 2007 4:23 pm

No mailorder to the states? You limey bastards!

All kidding aside, thanks for the help, I'll do that now.

bay · Post by **bay** » Thu Apr 12, 2007 4:42 pm

i just ordered a whole slew of astro style connector blocks in the group order. if you need some extra parts to make it all look nice, i've got some spares.

too bad you didn't mention the PSU before, that would have been a good group order inclusion.

Acid King · Post by **Acid King** » Thu Apr 12, 2007 4:52 pm

Yeah but I've been sitting on it for months now cause I've been dreading the work. I'm a lazy prick, what can I say? I can wait a bit longer, so if I can't find another in the states in the next few weeks, I'll hold off for the next group order. I'm getting DDP next week and I've had no trouble running Ra.De. so I know I won't have problems with that atleast. That'll be enough keep me busy til the next group order if need be.

Acid King · Post by **Acid King** » Wed Apr 18, 2007 4:06 am

Here's a question; do New Astro's and Blast Citys have the same style of power supply? Since Blast City's were use for Sega Bass Fishing cabs in the states, I'd have a much easier time finding one of those in the US.