Stars
Stern Electronics, 1978I have a Stars machine that I can't get to power up at all. I have a good working MPU, sol. driver and transformer assembly in it and I have checked the cord and wiring harness and both are fine, is it possible that the switch under the cabinet is bad? I have 120v at the plug in inside the bottom of the cabinet next to the chime assembly.
Thanks for any info on this.
All the power for the machine passes from the cord, through the switch to the Rectifier Board. J2 gets power from the switch, that passes into and out of the transformer back into J1.
Carefully, check power out of the switch and to the test points on the rectifier board. Remember, that's 120 VAC running through there.
Could be a bad fuse holder or a burned fuse.
faz
Ok, got it up and running, it was the 3 A slow blow fuse on the rectifier board. All coils, displays, gen illuminatio and gameplay is working but I have no lights under the playfield, what should I check for that?
Power to the PF comes from J1 off the rectifier board.
Coils, GI and CPU controlled lights. You did not say which lights are not working under the PF...GI or CPU Controlled.
I'm looking at the schematic from IPDB...page 28 of the PDF....upper right hand corner shows the connector layout.
I'm betting the connector is burnt or you have a break. Inspect the connector. If it looks toasty, rebuild the connector and/or the header pins. If all is good with that, you probably have a broken wire. Pull the connector and start running continuity tests.
Let us know how this works out!
faz
it's the lamps under the playfield that are not working, the ones below the inserts, all of the gen illumination on top of the playfield are working fine
The rectifier board is usually a mess on these games. I would assume your problem is connectors until you rebuild or replace the rectifier board and the female connectors.
Ok, those are the CPU controlled lamps (feature lamps). Check connector J1 (pin 7 to be specific). How's that connector look?
Did you check the testpoints off the rectifier board?
faz
What would be the problem with the rectifier board that would cause F6 (3A slow blow) to blow when I power the machine up?
Looking at the schematic. F6 is the main power feed into the transformer. There's a dead short somewhere.
Clay suggests: Check the varistor and the line filter in the cabinet.
faz
Well I tried another transformer/rectifier board and it will power the game up without blowing the fuse, so it has to be something on the rectifier board itself or the transformer assembly?
How about a picture of said board?
Wolf, if pins 6 & 7 were shorted, would the fuse blow? I would expect the circuit breaker in the house to pop. I would expect a short on the board between E1 and E2. Or the transformer is bad. I don't know how to test a transformer.
faz
From what I've read...transformers don't go bad often...but it could be damaged.
SkinnyLynny, did this game ever work before? What's the history?
faz
It was not working when I got it, had the MPU repaired, was working for a few months then the blown fuse thing. I took another transformer assembly that I had and it powered up and would play but with that one I did not have any lamps working under the playfield so I went back with the original transformer that has the fuse issue.
Ah, that helps a lot. Well, you have two boards... compare all the wires on the two boards.
E1/E2 are your prime areas of interest. How do the taps on the transformer look? Any hacks? Several lugs should be connected as to configure it for 120V. Compare the wire configurations on the lugs too.
faz
On the rectifier board remove all fuses except F6 and power up.
If F6 holds without blowing add the fuses in one at a time until you
determine which circuit is causing the F6 to blow.
You can check your varistor with fuse F4 removed power off using a meter. Measure for low resistance.
If you leave F4 installed, you will see a low resistance because of the transformer winding. A shorted varistor
will cause F6 to blow. The varistor protects the machine from high voltage surges and can commit suicide by shorting and blowing F6 to protect the machine.
Transformer outputs can be checked with a voltmeter set to AC, test points E3 to E4 should measure 49VAC
E5 to E6 should measure 11.3VAC, E7 to E8 7.3 VAC, E9 to E10 7.9VAC, E11 to E12 12VAC. You can sucessfully measure all these test point with all fuses removed with the exception of F6.
Wanna join the discussion? Please sign in to reply to this topic.
Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!
This page was printed from https://pinside.com/pinball/forum/topic/stern-stars-pinball-machine-no-power-no-gen-illumination-nothing and we tried optimising it for printing. Some page elements may have been deliberately hidden.
Scan the QR code on the left to jump to the URL this document was printed from.
Gulf Coast, AL
Sana'a