Blast City – Wiring

Originally posted Oct 12, 2020

Now I sorted out the monitors, it was time to start making my way onto the cab and seeing what else needs to be fixed.

First off the rank was power. I needed to figure out what was the status of the power.

This cab is 100v, so I purchased an external step down transformer from ebay as my test rig. I have plans to do internal step down at a later point in time (if I can be bothered )

Plugged the psu into its respective spots in the I/O, plugged the JAMMA harness with a pandora’s box as a test pcb… flicked it on and… nothing! No fan, no light, no sound, nothing! Boo!

Went over the cab again, made sure the “kill switch” at the door was pressed (even made the adapter for the kill switch), checked and replaced the fuse on the psu, still nothing.

Made sure 110v was coming out of the step down – check!

Unfortunately, I couldn’t find the reason it wouldn’t power on. I gave up for the night 

The following day, I was advised to check the Blast I/O if it was getting 100v, since everything has to go through the I/O before it can be fed back to the PSU. I started pronging around to find the 100v line and I eventually found where the 100v was and realised – wtf? It went nowhere!

So I did what everybody should always do first – RTFM!  

I found exactly what that connector did when I read the f***ing manual 

It’s clear in the manual, there’s a connector to loop back the 100v, so I made the little connector.

The moment I connected that, things started to work as expected 

After getting power to the cabinet, I tested the voltage of 3.3v, 5.0v and 12v. Both 3.3 and 5v needed to be dialed back but I didn’t realise the 12v didn’t have an adjustment pot on the blast!

5v right on 5.00

3.3v right on 3.3v

12v is slightly under – hope this doesn’t cause issues.

The last thing to check are the speakers – I’ve heard a lot of issue with the blast speakers, especially the challenges involved when you have to find a replacement.

I’m lucky to say both speakers appear to work – I haven’t bothered taken them out as I don’t really want to split the whole cabinet in half to get to the speakers.

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