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 Gmc500+ voltage		  New Topic  Reply to Topic
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Rainwolf511

USA
5 Posts
Posted - 09/22/2024 :  14:05:23  Show Profile  Reply with Quote
Hey all i have had my gmc500+ for a while now and it just suddenly quit registering pulses checking the voltage on the screen its only showing 40v and if i use my dvom to measure it at the tube is 13 or so vdc any idea what happened
Reply #1

nonus

34 Posts
Posted - 09/22/2024 :  15:22:13  Show Profile  Reply with Quote
Perhaps you have selected the operating mode only for tube #2.
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Reply #2

GTS

USA
33 Posts
Posted - 09/22/2024 :  15:32:24  Show Profile  Reply with Quote
Battery OK?
Charging OK?
You could do a master reset.
If all else fails, you could send it in for repair.
Edited by - GTS on 09/22/2024 15:33:18
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Reply #3

Rainwolf511

USA
5 Posts
Posted - 09/22/2024 :  16:14:34  Show Profile  Reply with Quote
quote:
Originally posted by GTS

Battery OK?
Charging OK?
You could do a master reset.
If all else fails, you could send it in for repair.


Best i can tell its charging fine and battery was at 60 to 70 % when I discovered this i tried to factory reset set it from the menus no change also i have it set for tube 1 only since thag is the higher voltage tube
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Reply #4

Stargazer 40

USA
431 Posts
Posted - 09/22/2024 :  16:53:42  Show Profile  Reply with Quote
Kinda sounds like something in the power supply. Perhaps a capacitor failed or is failing. It's a pretty simple circuit. You can adjust voltage (goes from 0-100). Depending on version there is an auto adjust that maintains when high cpm is reached. But the thing to try is raise the voltage number from say 40 something to 60 and see if any response. Been awhile since I've messed with that but don't think you'll see much improvement if a component has failed.
Stargazer 40
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Reply #5

Rainwolf511

USA
5 Posts
Posted - 09/24/2024 :  13:56:45  Show Profile  Reply with Quote
quote:
Originally posted by Stargazer 40

Kinda sounds like something in the power supply. Perhaps a capacitor failed or is failing. It's a pretty simple circuit. You can adjust voltage (goes from 0-100). Depending on version there is an auto adjust that maintains when high cpm is reached. But the thing to try is raise the voltage number from say 40 something to 60 and see if any response. Been awhile since I've messed with that but don't think you'll see much improvement if a component has failed.


Opened it up to try and figure out how the high voltage is made and where since its obviously not using the diode/cap ladder but could not find anything all resistorsbare in spec and i could not find and obvious caps that are blown or anything and with out a schematic or diagram its looking like it is a lost cause
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Reply #6

EmfDev

2238 Posts
Posted - 09/24/2024 :  17:12:03  Show Profile  Reply with Quote
Most likely its the capacitor or inductor. Capacitor C3 and inductor L1. both close to the + terminal of the long tube.
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Reply #7

Rainwolf511

USA
5 Posts
Posted - 09/25/2024 :  07:39:56  Show Profile  Reply with Quote
quote:
Originally posted by EmfDev

Most likely its the capacitor or inductor. Capacitor C3 and inductor L1. both close to the + terminal of the long tube.
the issue affects both tube 1 and tube 2 and when i probe around checking for shorts or anything something triggers and it will work for a little while then it stops again
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Reply #8

nonus

34 Posts
Posted - 09/25/2024 :  13:07:07  Show Profile  Reply with Quote
Tube #2 is less sensitive, it barely sees background radiation. You can see the voltage level in the settings for the tubes. Try changing the duty cycle % for tube #1, usually 35-45%. If this does not work, you can connect the m4011 tube to the terminals of tube #2 and select the operating mode of tube #2 only.
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Reply #9

Rainwolf511

USA
5 Posts
Posted - 09/27/2024 :  03:25:26  Show Profile  Reply with Quote
quote:
Originally posted by nonus

Tube #2 is less sensitive, it barely sees background radiation. You can see the voltage level in the settings for the tubes. Try changing the duty cycle % for tube #1, usually 35-45%. If this does not work, you can connect the m4011 tube to the terminals of tube #2 and select the operating mode of tube #2 only.
i get the duty cycles and stuff it is literally not generating high voltage when its acting up the voltage on screen is less that 100 volts at 100% and the actual voltage measured with a DVOM is even lower like less than 20 volts and this is at BOTH. Tube sockets
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Reply #10

Stargazer 40

USA
431 Posts
Posted - 09/27/2024 :  15:26:30  Show Profile  Reply with Quote
I'd get in touch with support and see about returning to get fixed.
Stargazer 40
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