| Author |
 Topic  |
|
|
wilsonamelie
United Kingdom
2 Posts |
 Posted - 04/03/2018 : 01:52:01
|
I had GMC 300 for the past many years. It used to work fine. But Now it has been sitting in a drawer for years with no battery in it.
Recently I decided to see what was happening with it, and installed a new battery. After it came to life I noticd the right hand side of the display incl the battery level meter display is faded..but more important is zero clicks.
Also i tried to contact [url=h**p://ukdth.com/toshiba-laptop-customer-service.php]Toshiba Support UK[/url] for more support.
While testing.. I noted it will count clicks when I touch the Multimeter probes.. I can make it count up to the alarm level of 100 and the alarm goes off. This actually shows the device is working.. but maybe the tube is not. Its had very little use..??
Is it likely its working and I really do have a zero BG radiation??
Also, visit [url=h**p://windows-support-me.com/]Windows Installation Support[/url] for more issues related to your windows. |
|
| Reply #1
ullix
Germany
1171 Posts |
Posted - 04/07/2018 : 07:51:30
|
It will certainly be wrong if you have zero counts. Expect something beyond 10 CPM, most likely less than 30CPM (if you lived in an area with higher background, you would probably know)
There are may ways these Geiger counters can fail. Since this happened after a longer time of no use, and the batteries are ok (?), chances are the tube is broken. Open the case (careful, high voltage at the tube contacts!) and look at the tube: there should be a faint rainbow shine inside the glass tube (from a vaporized metal deposit). If this is absent, in particular when you see a powdery appearance instead, then most likely the tube is cracked, air came into the tube, and the metal vapor deposit became oxidized. A new tube is needed.
If that is ok, electronic defects are the likely cause; repair is needed.
|
Edited by - ullix on 04/07/2018 07:52:32 |
 |
|
| Reply #2
John Galt
USA
1 Posts |
Posted - 10/16/2024 : 10:19:32
|
Sorry to revive this zombie thread..
I ordered a GMC-800 from Amazon the other day to use at Trinity day this weekend. Got my unit, turned it on and...... Nothing.. not a peep out of it.. no background count.. nothing..
I thought that was pretty strange so I started looking around the forums for any info.. While doing that I noticed a faint rattle when I'd turn my unit over. So, I opened it up and this is what I found...
quote:
Originally posted by ullix
chances are the tube is broken. Open the case (careful, high voltage at the tube contacts!) and look at the tube: there should be a faint rainbow shine inside the glass tube (from a vaporized metal deposit). If this is absent, in particular when you see a powdery appearance instead, then most likely the tube is cracked, air came into the tube, and the metal vapor deposit became oxidized. A new tube is needed.
While searching for an answer I came across your thread. I noticed that even though my tube was clearly broken and open to the atmosphere the 'faint rainbow' is still visible.
So.. I just wanted to throw it out there that a cracked tube can still exhibit the rainbow.. And, to thank Amazon for getting me another unit before I leave for White Sands...
|
|
|
| |
Topic |
|
|
|
Showing No counts with GMC 300.. what to do??
