Space Wars: No screen or HV adjustment

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Hi;
I just completely rebuilt my Cinematronics Ver. "A" monitor in my Space Wars project and the 2 pots, one for the screen and the other for the HV adjustment, do nothing.
The HV is 24.5kV and cannot be lowered or raised.
The brightness control does nothing either.
Another fact, the spot killer does not work.
I replaced all the components listed in the Cinematronics FAQs' and also most of the resistors and the rest of the caps as well, along with the resistors in the neck wiring.
I tested all the remaining transistors before the rebuild.
I checked the schems and thought that maybe IC7 was the cause but after replacing that, still the same....

I checked the CRT with my B&K and it shows that the CRT is functioning correctly (no shorts etc) and has good emissions but the CRT takes a very long time to warm up and the display, when it come up, is dim and washed out. I get a couple of bright dots but in general, looks poor.

Has anyone had a similar problem that they would be willing to share?

Thanks
Jeff
 

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Sounds similar to a newer cinematronics monitor I had that had a bad high voltage box (newer keltron style).
 
Last edited:
Sounds similar to a newer cinematronics monitor I had that had a bad high voltage box (newer keltron style).

Hi;
I'm getting over 24kV at the anode so I think that it is not the problem but I actually have no idea.
I really thought that by replacing IC7, the problem would have been solved but it is not going to be that easy!
Back to the schems......
Thanks
Jeff
 
http://www.outerworldarcade.com/arcade/cinematronics/manuals/cine_faq_v096.pdf

Another source for the older monitor info. Did you check the pots range with a multi meter to verify its working?

Back to the Space War:

I verified that the game does work by taking my Star Castle and Space Wars back to back and plugged the Space Wars ribbon cable to the Star Castle monitor and I could play Space Wars on the Star Castle monitor, sounds, controls, everything works........

Now, back to the Space Wars monitor.
I tested both pots, 10K (brightness) and 1Mohm (screen) and both wipe correctly.

I have a constant 24kV at the CRT anode and the screen control has no effect on the output voltage.

I have a constant 98vdc reading on all 3 legs of R11 (brightness) and the control has no effect on the output voltage.

I have deflection chatter as well.

Any insight / suggestion would be GREATLY appreciated........

Thank you

Jeff
 
did you read the whole cinematronics FAQ document? see if this helps

Symptom: No brightness control.
• Check intensity pot R11 for open wiper or internal short.
• Check for bad solder connections to R11.
• Check C17. Note: the only Cinematronics manual that shows C17 is Rip Off. All the other
manuals list C17 as a possible cause in the troubleshooting section, but they do not show the capacitor on any of the schematics. Although the Rip Off manual shows C17 as a 10uF 150V cap tied to one of the three terminals on the brightness pot on the monitor board diagram, the capacitor is not on the schematics.
 
did you read the whole cinematronics FAQ document? see if this helps

Symptom: No brightness control.
• Check intensity pot R11 for open wiper or internal short.
• Check for bad solder connections to R11.
• Check C17. Note: the only Cinematronics manual that shows C17 is Rip Off. All the other
manuals list C17 as a possible cause in the troubleshooting section, but they do not show the capacitor on any of the schematics. Although the Rip Off manual shows C17 as a 10uF 150V cap tied to one of the three terminals on the brightness pot on the monitor board diagram, the capacitor is not on the schematics.

Hi;
--I checked both the HV and R11 (brightness) for proper operation and they both checked out 100%
--I checked for resistance through the soldered connections and all check out 100%
--I checked C17 (10uF cap) and it also checks out 100% (I am using the Rip Off manual as it is the closest to the Space Wars monitor layout)

I also jumped out Q2 to no avail......

NOTE: R14 (500ohm 8w) gets super HOT......

I checked for +5vdc at R1 and R2:
R2 runs from south to north and I get +4vdc on the south end, mV on the north end
R1 runs from west to east and I get +4vdc on the west end, mV on the east end??
Is that correct??

One other question, as the output is a little over 24kV at the anode, will that have any harmful effects on the human body????

Thanks
Jeff
 
24kV is 24,000 volts...twenty four thousand volts...don't touch it on purpose or by accident

Hi;
Thank you for the warning.... but what I meant by "harmful to the human body" was with regards to radiation, as the voltage increases, the possibility of damaging X-Rays increases.........

The manual states 18kV for the "discrete" and 16kV for the Keltron style and as I had pointed out that I cannot lower the voltage, I just want to make sure I am not going to permanently harm myself trying to repair this monitor........

It's really getting to me as I have the deflection chatter and I have upgraded or replaced almost every single component and the ones I did not replace, I tested, I need a guiding light to get me through this.

I'm going to try and get some sleep as I'm sure my children will be getting up in a couple of hours..... DAMM THESE YUENGLINGS!!!!

Thanks
Jeff
 
you might want to contact cinelabs...they work on vectorbeam and cinematronics stuff

If all else fails, that is what I will do.

I look at these situations as challenging puzzles and like the saying goes, "if it doesn't kill you, it'll make you stronger".

So as long as I don't start glowing in the dark or my balls fall off from radiation exposure, I think that eventually I will solve this enigma, (with the help of my fellow KLOV'ers).........

Jeff
 
don't worry about the x-ray part...electricity to the anode, no matter how much there is, isn't x-rays (x radiation)...24k volts will knock the crap out of you, but it won't x-ray you...just don't touch the anode when it's on...
 
don't worry about the x-ray part...electricity to the anode, no matter how much there is, isn't x-rays (x radiation)...24k volts will knock the crap out of you, but it won't x-ray you...just don't touch the anode when it's on...

Hi;
I understand the voltage issue, in fact, one night many years ago while I was working on a game, i inadvertently touched the CRT anode port while reaching over to another area in the monitor and received a nice little reminder through my arm not to ever do that again!

There is a reason for the protection circuit on monitors, it is there to shut down the HV when it reaches a predetermined set point to avoid harmful X-Ray exposure. My concern is that since my HV is going full out, is it producing any dangerous radiation. If I had a Geiger counter, I would know for sure what the exposure level is.

This monitor HV should be running at 18kV, so it is obviously too high and as the HV pot does nothing and I cannot lower the voltage, I am just concerned.......

Also, the HV section is integral with the deflection PCB and I cannot isolate it to troubleshoot the monitor.

Jeff
 
Not yet but I have not given up.
I am waiting for a delivery from Mouser and hopefully once received and then implemented, I will have conquered!!!!
I'll probably know by the end of the week.
Jeff
 
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