More on Power

OK. Talked to a local expert on these things. Turns out I was measuring wrong. I was expecting DC power when it was still AC power. So, the good news is that I am now getting 12VAC and 7.5VAC from my main power supply. Yippee!

Now, on to the main circuit board. I mistakingly thought I needed an auxiliary board simply because it was missing and it was in the schematics in the manual. You would think this would be a safe assumption. Turns out it was a wrong assumption. Again, after talking to my local parts guy, he told me to look for some rework wires on the bottom side. If they were there, then it was a "modified" board that did not need the auxiliary board. Lo and behold, I had rework cables and the auxiliary board is not needed (I'm still going to hold on to it, just in case though.)

So, checking the power on the main board, I found that I was only getting about 1.19VDC when I should've been getting about 5VDC from the Base pin on the power supply. I looked at my edge connector and noticed it had "burnt fingers" which indicates that the connector is not making good connection and is arcing over to the pad. I pulled the connector pins out a bit to try to make a better connection. This seemed to work a little better. I am now getting 4.5VDC and a lot of random noise out the speaker. However, the edge connector is getting really hot near the 7.5VAC pins (precisely where the burnt marks are already). So, either I'm still not making a good connection, or I have a short somewhere. I examined the board pretty well, and did not find any shorts on power rails. So, I'm thinking I probably need to replace the edge connector. One website said that some folks just bypass the connector altogether and solder the wires directly. Don't think I want to do this - just seems like a cludge.

Oh yes, and also found the brightness control on the monitor board. I adjusted it all the way up and turned the screen white. According to the parts guy, this is apparently a good sign and an indication my monitor is in good shape. We will see.

Hopefully, with full power restored, I'll get the thing to at least boot up and see something work on the screen.

UPDATE: Apparently, the edge connector blow out is pretty common (see: http://www.homearcade.org/BBBB/pace.html)

The Beacon Is Lit!

I was able to work on this most of today, except for when my boys persuaded me to engage in a water balloon fight. I vacuumed the entire thing out and replaced the proper fuses. Also attached a new power plug onto the end of the power cable. Turned out the first time that I got Line and Neutral mixed up and no power was getting through. Switched those around in my splice rework and got power going to the primary side of the transformer, but on the secondary side I am only getting 0.2V and 0.3V when I should be getting 12V and 7V.

However, the florescent bulb now lights up! Going to have to figure out what is going on with the transformers...

First Things First

I've decided to tackle the power system first, since I won't be able to diagnose much else without POWER. All fuses are missing and the power cord has been cut. These are fixed easily enough. Hopefully the transformers are OK and I can get the proper power out of the board once I replace the fuses and cord. As you can tell from the picture, it is also VERY dirty.

Restoration project begins!

Hi all,

This blog is dedicated to the restoration of a Ms. Pacman arcade machine. This particular machine was found by a friend in an old building in downtown Durham NC. She is renovating the building to provide affordable office space and wanted this machine to be restored as well.

Hope to be done in about 3 months. Pictures will be forthcoming!

Jason