Getting my feet wet... CENTIPEDE wont power up.

CyberDude

Member
Joined
Aug 6, 2016
Messages
368
Reaction score
11
Location
Utah, Utah
I got a CENTIPEDE from a buddy of mine for work I did for him. Its been just sitting in a garage uncovered for many years. I knew ahead of time it wasnt powering up but decided I would make it my first project machine and try an fix it myself. I have never repaired an arcade machine before but Im gonna give it a try. Here is what is going on. When I plug it in I hear a quick crackle noise and the red light on the PCB comes on solid. The monitor is not coming on and I can hear a slight hum coming from the speaker. And thats it. When I unplug the machine the monitor does a quick flash and the machine shuts off. I am researching Youtube for HOW TO troubleshoot arcade machines and reading posts here but to be honest Im pretty scared. I have a electronics background but no experience with arcade machines. I own a FLUKE meter but thats all I have at the moment. I started with the power brick and all the fuses are good. Next I will figure how to test voltages. I will update my progress as I go.

Here is a pic of my power brick. If any of you guys see something thats not right please feel free to comment. I will take all the help I can get and be very grateful. Thanks. Michael

 
It sounds as though the PCB and monitor ARE getting power.

You might try reseating the 2 edge connectors at the PCB.

You'll NEED to verify the voltages. There are test points on the AR2 board - the one with the large heat sink - that's the power supply and audio amp all in one board.
 
Measure the voltages at the test lugs on the PCB. Drops can occur from the AR2 to the board edge due to age/oxidation. Report back on what you get and we can help you go from there.
 
I removed the whole power brick from the cabinet to give it once over and clean it up a bit. I also ordered a BIG BLUE cap to replace this original one. I should have it in the mail in a few days. Once I swap it out I'll put the brick back in and fire it up. I am hoping for a miracle quick fix but I doubt it. LOL I will check voltage on the PCB then. Thanks for the help so far.


Measure the voltages at the test lugs on the PCB. Drops can occur from the AR2 to the board edge due to age/oxidation. Report back on what you get and we can help you go from there.
 
New big blue never hurts. Bridge rectifier is the part on the brick that can fail, but no blown fuses is a good thing. You'll want to recap the AR2 at some point, but the parts that typically crap the bed on there are the 3055 transistor on the big heat sink, the voltage regulator, or the trim pot for the voltage regulator. Are the resistors at R29 and R30 ok?
 
Voltages might be OK.
First -> coin it up, do the start LEDs blink? Does it "play blind"? Can you hear the game playing?
Next -> flick the test switch and listen for beeps.
 
Ok... While I wait for the BIG BLUE to show up in the mail I said what the heck and put the power brick back in and powered it up to check voltage readings. On the PCB I see a +5V little ring and about 4 inches straight up from it is a GROUND ring. When I put my FLUKE on there it reads 9.77 VDC. This is all I have done so far. Any thoughts on why thats reading so high? Or is that high? Thanks. Michael

 
Last edited:
Once I turn the machine on all that happens is the RED light on the PCB comes on. The PLAYER 1 and 2 lights are on solid and I can hear a low hum coming from the speaker. When I flip the test switch NOTHING at all happens. Monitor flashes for a second when I power the machine down. See my post right above this one for a voltage reading I did on the PCB.


Voltages might be OK.
First -> coin it up, do the start LEDs blink? Does it "play blind"? Can you hear the game playing?
Next -> flick the test switch and listen for beeps.
 
Last edited:
Time to rebuild the ARII. :(
Don't continue to power the logic board till you get 5.0VDC on those test points.

EDIT: here's a rebuild kit (likely overkill for what you need) and, unfortunately, it does not include the regulator IC -> https://iankellogg.com/parts-by-category/rebuild-kits/atari-ar-ii-02-03.html

Includes

  • 4 - 3300uF 50V Axial Caps
  • 3 - 470uF 25V Axial Caps
  • 1 - 1000uF 25V Axial Cap
  • 2 - 22uf 50V Axial Caps
  • 2 - 1.0uF 50V Axial Caps
  • 1 - 2n3055
  • 1 - TIP32C
  • 1 - TO3 Insulator
  • 1 - TO-220 Insulator
  • 1 - 2.7 Ohm 1W Resistor
  • 2 - 10 ohm 1/2W Resistors
  • 4 - 1N4007 Diodes
  • 1 - 7812 12V Vreg
  • 1 - 7905 -5V Vreg
 
Last edited:
Should I unplug the PCB and start metering all the DC voltages on the ARII then? Thanks


No, just worry about the +5 for now. Ideally you should have your leads clipped on to the +5 and GND test points and be ready to shut the game off if the voltages are too high. That goes for any game you test going forward too.
 
I have a working TEMPEST and a DIG DUG. Is the ARII in either of those the same as the CENTIPEDE? And would it be wise to take a working ARII out of one of those and test it in the CENTIPEDE or could I risk damaging that good ARII? Just a thought. Thanks
 
Here is a good ARII resource page ->

http://www.elektronforge.com/AudioRegs.htm

It summarizes well what each power board provides and in which game each version is used.

If you eventually find the ARII is bad, then there are vendors here on KLOV which sell refurb'd/tested ones if you are not confident to fix yours.
I would guess you could also negotiate a trade + cash for a working one. YMMV
 
Thanks VectorCollector I appreciate and respect your opinion. So after looking at the link you provided It looks like the TEMPEST ARII is the same as the CENTIPEDE. So should I just take the ARII out of my TEMPEST and see if it fixes the CENTIPEDE?


Here is a good ARII resource page ->

http://www.elektronforge.com/AudioRegs.htm

It summarizes well what each power board provides and in which game each version is used.

If you eventually find the ARII is bad, then there are vendors here on KLOV which sell refurb'd/tested ones if you are not confident to fix yours.
I would guess you could also negotiate a trade + cash for a working one. YMMV
 
Thanks VectorCollector I appreciate and respect your opinion. So after looking at the link you provided It looks like the TEMPEST ARII is the same as the CENTIPEDE. So should I just take the ARII out of my TEMPEST and see if it fixes the CENTIPEDE?

"Give a man a fish and you feed him for a day. Teach a man to fish and you feed him for a lifetime." :)

It's up to you. I cannot recommend one way or the other due to the risks involved.

I typically test mine on the bench to be safe as I have the benchtop test equipment to do so (power supply, electronic load, DVM, etc) ... and I'm pretty conservative when it comes to testing my games etc. Jeopardizing one to save another is risky, IMHO.
 
By all means recap the AR2, but there's a problem with the +5v regulation there and a cap kit plus power transistor isn't likely to fix it. I'd highly recommend replacing the voltage regulator (small silver can near the trim pot), and get a new trim pot while you are at it. I've found either or both of those bad numerous times when the 5v line was out of whack.

Arc is right. You'll need a load on the AR2 that's provided by the PCB to make adjustments, but allowing 9v to pump through to the PCB for any length of time might take out components on the PCB. You can use the AR2 from your Tempest to confirm that there's an issue with the AR2 (almost a certainty here) in the Centipede. Once you are getting good 5v to the PCB, then it's on to troubleshooting the board if it still doesn't come up.
 
My first guess - 2N3055 Q3 is short. Can ohm it out and validate. (if low impedance, voltage drop from 10.3Vdc unreg to the noted 9.7V could be seen)
My second guess - LM305 Q1 is dead. Replace.
My third guess - both these parts are bad.

Double check R29 and R30 remote sense resistors are still 10ohm (and not high impedance). I believe this can cause over-voltage.

NOTE: if either sense resistor is shown to be incorrect higher impedance, then this may imply poor edge connector contacts and this would then need to be investigated too.
 
Last edited:
Ok... If time permits tomorrow I will take the AR2 from my TEMPEST and try it in my CENTIPEDE and see if it sends the correct 5VDC to the PCB. I will post my findings after doing so. Thanks for the help. Its much appreciated.

By all means recap the AR2, but there's a problem with the +5v regulation there and a cap kit plus power transistor isn't likely to fix it. I'd highly recommend replacing the voltage regulator (small silver can near the trim pot), and get a new trim pot while you are at it. I've found either or both of those bad numerous times when the 5v line was out of whack.

Arc is right. You'll need a load on the AR2 that's provided by the PCB to make adjustments, but allowing 9v to pump through to the PCB for any length of time might take out components on the PCB. You can use the AR2 from your Tempest to confirm that there's an issue with the AR2 (almost a certainty here) in the Centipede. Once you are getting good 5v to the PCB, then it's on to troubleshooting the board if it still doesn't come up.
 
Well I just couldnt wait. I put the TEMPEST AR2 in the CENTIPEDE and the voltage is now 5.11 VDC at the PCB. And the monitor comes up but its just a YELLOW screen. The PLAYER 1 and 2 lights are still SOLID RED. When I flipped it into TEST mode there is NO change. Where do we go from here?
 
Back
Top Bottom