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avatar: stein-rune
stein-rune
4 posts
Replied to stein-rune's post on April 16th, 2012

Where can I locate the door sensor? I have a door alarm that says Door is open. The door is closed.

avatar: Emma_W
Emma_W
8 posts
Replied to stein-rune's post on April 17th, 2012

Hello stein-rune,

I recommend you contact our Technical Support team at 800-438-4851 in North America.

If you're located in another region of the world, please use the ‘Contact Us’ tab on our website: http://www.thermoscientific.com, and select your country and product line to find the correct telephone number (or submit a request for help).

Kindly retrieve the serial number of the unit prior to contact so that the team can verify the exact model and age of the unit.  
 
I hope this information helps.

avatar: wbeaty
wbeaty
15 posts
Replied to stein-rune's post on August 11th, 2017

There is no door sensor, instead the steel frame of the glass door is connected to +5VDC wrt chassis ground, with signal leading to the CPU card.   When the door is closed, the small leaf-spring located under the circular black latch-knob will touch the door frame, shorting the 5V to ground.

Failures:

- Door hinges moved, so the latch spring doesn't touch the steel frame of the glass door.  Loosen the hinge mounting screws, then tighten them while pushing the entire door towards the latch, so it compresses the spring when closed.

- Cable conductors internal break (every time the door opens, it twists the cable, which eventually fails.

- Cable connector crumbled.  The plastic gets destroyed by the acidic CO2 atmosphere under the outer door.

avatar: medphysteo
medphysteo
232 posts
Replied to wbeaty's post on August 11th, 2017

Also, the leaf spring can break leaving the door frame without a contact, and the spring and the frame can get corroded. Make sure the contacts are clean, and if the spring is broken, it's just a AA battery connector