Atari ROTJ Power?

HighScoreSaves

Well-known member

Donor 7 years: 2013-2019
Joined
Mar 23, 2007
Messages
15,831
Reaction score
757
Location
Blaine, Minnesota
Ok, I just picked up the ROTJ cockpit and am having an issue with the power.

I was looking at the schematics and noticed that the power brick in the game currently, did not have F2 populated at all. No wires, no fuse. The schems show all 5 of F connections being used.

I swapped in a power brick from a known working game (centipede) and powered up. Nothing but blank raster. Lights up the cab lights, coin door, powers the monitor, etc.

Then, I noticed that the J6 plug was not plugged into the ARII pcb. I plugged it in (with the new power brick) and got a LOUD buzz through the speakers.

For the first (even though brief) time, the pcb showed power by the red light. I left it on for about 3 seconds, blew the fuse on the brick at F4.

Any ideas what is causing this?
 
Well, I put the original brick back in. Left the ARII with a known working one. Left J6 plugged in, it popped the F4 again on the brick.

Short? bridge?
 
Well, the fuse won't pop with the J6 on the ARII unplugged. That is a guarantee.
I'm stumped, any ideas?
 
Do you know if the game pcb is ok? You could try hooking your own external power to the PCB and monitor to see if it plays and you get video.

Are the voltages coming out of the AR OK with the transformer block connected but not the PCB?


Bill
 
Does it blow if you have everything disconnected except the ARII and the Power Supply?

i.e. No PCB, No Lights, No Coin Door, etc...?

I just tested that again (and used the last of my 4amp fuses) and realized I still had the monitor connected.

So everything else disconnected it still blew the 4 amp fuses.
 
I just tested that again (and used the last of my 4amp fuses) and realized I still had the monitor connected.

So everything else disconnected it still blew the 4 amp fuses.

Well, the good news, is you've just eliminated a bunch of stuff as being the cause :D

Since you tested it with a known working ARII, it has to be an issue on the Power Supply.

Do you have a spare that you can swap out to confirm?
 
I have one from a Centipede. Would that work? Connections are a little different.

The Bridge is fine, the cap is fine (even though I ordered new from Bob). Going to replace the cord and fuses, when those get here on Thursday. Also a rebuild for the ARII.

It is just puzzling to the cause of this.
 
I've got an upright that was popping fuses as fast as I could install them when I first brought it home.

I put a new big blue, bridge rectifier, and rebuilt the ARII all at the same time. Solved the fuse popping problem.

-JM
 
Look a little closer at the scat my friend.

The negative side of big blue is tied to the center tap of the winding that is used for F4 & F5, this is true but is that technically in circuit with the two 36Vac lines that run through F4 and F5? Could a failure of big blue cause the F4 and F5 to blow? Assuming you are getting an output voltage from the center tap and the circuit is faulty at big blue I'm missing how that can affect the outer lugs?
 
The negative side of big blue is tied to the center tap of the winding that is used for F4 & F5, this is true but is that technically in circuit with the two 36Vac lines that run through F4 and F5? Could a failure of big blue cause the F4 and F5 to blow? Assuming you are getting an output voltage from the center tap and the circuit is faulty at big blue I'm missing how that can affect the outer lugs?

This is my question too. The only way that I could see it coming into play, is if big blue was internally shorted. *shrug* Can't prove it, cause I don't have a bad big blue laying around to try it with.
 
Back
Top Bottom