Paperboy Power Help Needed

Gamer4Life

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I picked up a Paperboy a while back to restore. It was working when I got it, then it started having issues. It would boot fine and play for a few minutes then the graphics would go nuts then rest. So I checked the voltages and the 5v was fine(it has a switcher in it) but the 10.3 on the ARIII was only at 4.5 volts. I figured no big deal I was goint to rebuilt it and the PS anyway. I rebuilt the AR and then I was getting 12.5 at the 10.3 TP, and it was blowing the F3 fuse (25A 32V). I went ahead and rebuilt the PS with new caps(both), fuse block,bridge. No luck it comes up to a white screen and I can hear it just resting over and over. I checked the 10.3 TP again and now its only getting 5.something. Anyone have any ideas on where to go next?
 
Disconnect the big power brick from the ARIII and flip the brick up on its side. (It might make sense to remove it from the bottom of the cabinet.) Connect your multimeter's electrodes to the two leads coming out of the + and - of the big blue nearest to the bridge rectifier. Measure DC voltage here, as well as any residual AC. Do this again for the second big blue. Let us know what you find for values. We first need to determine whether or not your brick is actually supplying the 10.3 VDC unregulated that the ARIII needs.

There are a couple of scenarios that could be happening. 1: There is something wrong with the rebuilt power brick, and it is not delivering the voltage you need to the ARIII. 2: There is something wrong with the ARIII, and it is dragging down the supplied voltage due to a short or malfunction of some sort.
 
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88 thanks for the reply. I checked both caps and I am getting 5.2v at both and 1-5v ac at both. I double checked the bridge wiring and its good. I even swaped out the bridge with the old and got the same results. What should I look for next?
 
You could do what I did after an ARIII rebuild didn't help my power problems. i disconnected the +5 wiring from the ARIII to the bottom board, then connected the +5 and GND test lugs on the bottom board directly to the switcher. Game runs fine now...
 
88 thanks for the reply. I checked both caps and I am getting 5.2v at both and 1-5v ac at both. I double checked the bridge wiring and its good. I even swaped out the bridge with the old and got the same results. What should I look for next?

Ok, now we're getting somewhere. You did make sure to disconnect the ARIII, from the power block, right?

You should have more than 5.2V coming out of your big blue. It also sounds like you are getting too much AC on them as well.

Let's go one step further up the chain. Disconnect the wires that feed AC to your bridge rectifier. There should be 4 wires connected to the bridge rectifier; the ones I want you to disconnect are the ones that aren't connecting it to the big blue. Connect the wires you removed to your multimeter, and measure how much AC voltage is on them. Report back with that value.

What should be happening is this--stepped down AC from your transformer goes to your bridge rectifier. The bridge rectifier separates out the + and - phases, and the big blues are there to 'smooth out' the 'bumps' in the voltage, giving you (roughly) 10.3 VDC. Let's see what kind of AC you're feeding the bridge rectifier...

Also, while you have things taken apart, you should check the individual diodes on your bridge rectifier (may as well disconnect if from the circuit for this). The bridge rectifier is made of 4 diodes, which you can think of as one way current flow controllers.. they let current go in one direction but not the other under normal circumstances. Your multimeter may have a mode for diodes. Check and see that all of the diodes are working properly.
 
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Ok here is what I came up with

Incoming AC is 116
Bridge is good with .5-.6
14.8 On the incoming ac line to the bridge

Here are the voltages at the 15pin connector
1-10.7
2-10.8
3-11.1
4-11.8
5-12
6-28.4
7-3.9
8-1.6
9-3.3
10-3.0
11-1.8
12-30.3
13-11.1
14-15.3
15-37.9

Thanks again for the help
 
Ok here is what I came up with

Incoming AC is 116
Bridge is good with .5-.6
14.8 On the incoming ac line to the bridge

I'm assuming the .5-.6 is the forward voltage you measured across each diode in your bridge. That sounds about right.

Now that we know that you are putting 14.8 VAC into the bridge rectifier (which sounds good), reconnect those leads to the bridge rectifier. Switch your multimeter into DC mode, and measure the voltage across the other two leads of the bridge rectifier without them connected to the big blue. It should be roughly 10-12 VDC (unregulated/unfiltered). If your value is much lower than that, you may not have the bridge connected properly.

Check out this image:

http://upload.wikimedia.org/wikipedia/commons/2/2c/Diode_bridge_alt_1.svg

Make sure that you are connecting the AC to the corners of the bridge rectifier that have both a diode pointing to and away from that point. If you have it hooked up any other way, it is not going to put out the voltage that you need.
 
Ok I cheked that and I was getting 6.2 with them not connected. Now while they were still disconnected I check the caps and they were at 13.2 along with the 10.3 TP on the ARIII. The game booted up just fine when I check the AR TP played it for a few minutes and turned it off. I didnt change anything other than reflowing the joints on the tranformer. So why am I getting 13.2 at the caps with and without being connected to the bridge? Should I put the old bridge back in since its good and check the voltages again?
 
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