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                | PolskaCanada | Posted - 09/02/2022 : 12:28:15 Hello, I haven't used my GMC-300E Plus counter for a few years.
 Now, after replacing battery I get no signal at all/
 Counter is permanently on "0"
 and before it was always showing some radiation.
 Is it a problem with counter?
 Is it broken, or something needs to be set:
 all the counter functions seem to work - I set date, display etc.
 
 I would appreciate advice.
 
 Aleksander
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                | 1   L A T E S T    R E P L I E S    (Newest First) |  
                | ullix | Posted - 09/04/2022 : 08:04:10 Well, this is odd - I had already posted an answer, and I see now that my post has disappeared. Strange, I'll try one more time.
 
 1) do a factory reset. Any counts now?
 2) remove the battery for at least 1 minute. Do another factory reset. Any counts ?
 3) Measure the anode voltage from one end cap of the tube to the other with a DVM. Voltage is then expected somewhere within 100 ... 160V. What did you get?
 4) Do you have an about 1 GigaOhm resistor? Put it in series with your DVM and measure anode voltage again. You should now measure near around 4V, meaning your anode voltage is ~400V (this is where it should be).
 4a) remove the tube from its holder clamps. then repeat #3 and #4 by measuring voltage at the holding clamps. Results?
 5) Can you run GeigerLog with the counter? Please post the output of menu: Device->GMC Series->Show Extended Info.
 6) Can you read out the counter history using GeigerLog? Does it show anything? Anything but zeros?
 7) remove the back of the counter, and look closely: any obvious damage? Do you know how capacitors look like? Do you see one "bulging"?
 
 
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