Centipede Power- I'm sorry, I'm sure this has be asked a million times.

goldiedpimp

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Centipede Power- I'm sorry, I'm sure this has be asked a million times.

I've got a centipede cabinet that worked fine until last fall. I went to power it up and she's dead.

Coin doors light up, power led on main board lights up, but no sound or anything on the monitor.

I checked voltages and things just don't check out right. On the AR board, AC side where I should be getting 36vac, I get 17. Some of the other voltages are PRETTY close, others are way off on the AR and the main board.

I took the ar board out and inspected, reflowed all the solder joints, and found nothing else obviously wrong. I didn't get the multimeter out to mess with individual components.

I pulled the brick out of the bottom. The bridge seems to be functioning. Nothing seems burnt and all the fuses check ok.

What's the next step?

Do I just order a ARII rebuild kit, rectifier and big blue? (if so, where from these days?) I don't want to just throw parts at the issue and hope it fixes it. It seems from what I've seen that this should cure it?

What do you experts think?

Thanks!
 
is the game playing/can you hear it and did you measure the 5vdc line at the game pcb?? did you check the fuse holder for corrosion or loose connections? if you need parts/kits i stock all the best parts for the power brick and AR boards.
 
You might have AC ripple on your +5 rail. If you set your meter to AC volts and measure the +5 line, what reading do you get?
 
What ieure said.

Also, if it's playing blind, it's common for the video output sections of the game boards to go on Centipedes, which can kill your video. It would need a board repair in that case.

Also, your AR is likely fine. Don't spend money on a rebuild kit unless you can measure that it is bad, and even then you don't need to cap it. The AC must be measured between the two 36v test points. If you only measure one of them to ground, you will only get 18V.
 
It doesn't appear to be playing anything at all. There's no sound for anything, and nothing on the monitor.

I'll double check voltages in the morning and see what I can report.


What's usually involved with the board repair you speak of for the video?
 
It doesn't appear to be playing anything at all. There's no sound for anything, and nothing on the monitor.

I'll double check voltages in the morning and see what I can report.


What's usually involved with the board repair you speak of for the video?


There are output buffer chips for the sync signals that can go bad, as well as the drive transistors for the color signals. You need at least a logic probe to troubleshoot, and optionally a scope.

But if the game isn't playing at all (even without an image, i.e., no sound or any other indication that the game is playing in the background), you may have more significant board issues, which can be in any one or more subsystems on the board.

But as ieure said, bad power is a common issue, particularly bad big blue caps causing too much AC on the DC supply. So that is the first thing to check.
 
Agree with everything andrewb and ArcadeDanger have to say here.

You might also check your AR2 board for burnt resistors. R29 is a common failure and is easy to spot just by eyeballing the board.
 
I'm not seeing anything visibly wrong. Until a few years ago, I was certified for assembly and inspection of aerospace electronics. I moved to a different job and don't have the actual certs anymore though.

I took voltages and I think this is all of them.

On the AR board. Looking at it with the AC side at the top I get.I guess I didn't jot down what the pcb says the voltage should be on all of them. If it's not enough info, I can get the correct values to post.

36vac =35.2
-23.9
+22 = 23.7
+12.3
-5.1

Dc side of the board
10.3
12.1
sens 5.1



On the main board

5v = 5?? (can't read it)
-22 = -23.9
+22 = +23.6
-15 = 0
+15 =15.3
-30 = -12


Does this give anyone any ideas where to look for issues?



Thanks
 
Replace the -15V regulator on the board (7915). That should also fix the -30V as well, as it is derived from the +15 and -15V.

Also, when you have the 7915 removed, test to see if there is a short between the output (i.e., the -15V test point) and ground, as it's hard to know if the regulator failed on its own, or if it died because something else shorted it out. If there is a short, don't install the new regulator until you figure out what part is causing the short.

If there is no short, you're safe to install the new regulator and fire it up, but test the voltages first, with the monitor unplugged.
 
Awesome.! I'll get a 7915 on the way. I need to order other parts, so I'll be making a digikey order.

Are there any other parts that i may want to order "just in case".? It might be easier to waste a few bucks now instead of having to pay $20 postage for a couple of $1 parts.


Thanks!
 
There isn't anything obvious for this repair. If you want to get into board repair, there are tons of things you could order, but it's a slippery slope. But for this repair you won't know what else you might need until you replace that regulator. You can try removing it and checking for a short as I described, but that's about all you can do right now.

These regulators can be purchased almost anywhere. You may get cheaper shipping from someplace like greatplainselectronics.com or arcadepartsandrepair.com, if you only need a couple of parts.
 
I've already got a digikey order going. I build boards for paintball guns and have to get parts ordered for that anyway.
 

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So I just installed a new 7915. I finally got around to it.


It didn't work. It's feezing in my shop right now, so I didn't mess with taking any voltages.

I have this feeling that I could start going down the rabit hole trying to fix this myself.

What are the costs of having a board looked at inspected by someone who knows what they're looking at?

By the time I'm paying for shipping both directions, would it be cheaper just to buy another board?

I'm really not sure where to go at this point.
 
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