Atari Centipede Cocktail table game has no power

Arcade Collecting > Restorations & repair

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PL1:

--- Quote from: vapuser on April 14, 2020, 07:01:16 am ---Additionally, one of the 10K 2W resistors that showed a low “in circuit” reading was actually very close to the 10K value after I removed it and retested it. I should probably just leave the resistors alone. Is that typical? That a resistor “In circuit” value will show a different reading after being removed from the circuit?

--- End quote ---
That can happen when there is more than one path from one meter lead to the other.

If you try to measure R1 in--circuit, current can also flow through R2.
(Assume the battery has been disconnected since you should never take resistance readings with power applied.)

To accurately measure R1, you would need to either:
1. Desolder a leg and lift it clear so there is no path through R2 to the lead on that leg.
or
2. Desolder both legs and remove it completely from the circuit.

Scott

yotsuya:

--- Quote from: vapuser on April 14, 2020, 07:01:16 am ---Good morning all, Well, some of my electrical components finally came in the other day. One of the parts that I ordered was a replacement for the cracked Ceramic capacitor that is soldered to the H/Out transistor as seen in the above picture. That original cap is probably the size of a dime. The replacement part that came in is probably the size of a pea. Does that sound right? The part is a 151J which is a 150 pf 1.5 KV AC 5% Tolerance Ceramic cap. The description of the new part is identical (Actually a 2KV) but so much smaller. Should I be concerned?

--- End quote ---

It’s been 40 years - electronic components have evolved and gotten more efficient. I wouldn’t give it a second thought. ;(

vapuser:
Good morning all, now that all the components have been restored, I turned the unit on, and the screen finally lit up. It only stayed on the main centipede game screen for about 5 – 10 seconds then went black. I can turn up the brightness, but then all I get is a white screen. I also turned the RBG knobs and only got a slight hue of those colors. The both fuses don’t blow anymore. I checked the B + and I have a DC voltage of 119.5. Is it critical that the reading be exactly 120vdc? According to the documentation, the adjustment reference R909 is not on the board. At least, not that I can find. Please see pic below. Can someone send me a picture of the adjustment potentiometer? I thought for sure everything would have been good except for a few minor adjustments. Not sure where to go from here. Does anyone have any suggestions?

bperkins01:
.5v will not make a difference. If your screen is getting scan lines (meaning you can turn knobs and get see anything like you said - white, red, green) then the issue may be in the circuits that take the video signal in.. or your video ground has disconnected in the connector.

Is the power LED on - on the game PCB? are you sure the PCB didn't lose power?

vapuser:
perkins, I turned the game on again when I got home from work to take a closer look as to what is going on. When I turn the game on, everything looks normal for a total of about 40 seconds. The game shows the high score screen with red lettering for about 15 seconds. Then the lettering will turn to green for about 20 to 25 seconds. Then to yellow for a few more seconds, then to a black screen. At that time I looked over at the PCB board and the LED light was still on. I can do this repeatedly (turn it off and on) and it will basically do the same thing each time. Although, one time I turned it on and the screen just went right to a black screen. But when I turned it off and back on again it repeated as above. What are your thoughts?

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