Turning off a sigma bc 506 - Sigma Cycling

Remove the battery. With most bike computers the display typically is always on. Here's the manual:
SIGMA SPORT BC 600 Manual

I’m happy to help further over the phone at https://www.6ya.com/expert/donald_f2ed37026a3ac881

I already referred you to Google and to Sigma support, but it sounds as if you probably need to replace the unit. It should work when you replace the battery, even if you have not set wheel size, as all bike computers come with a default setting. There is no way to "fix" such an inexpensive device (under $25 with shipping)
https://www.shop.com/Sigma+Topline+Wired+Bike+Computer+BC506+05160-1484064483-p+.xhtml?sourceid=298&CAWELAID=120179650032541809&CAGPSPN=pla&CAAGID=18133145218&CATCI=pla-152669075578&catargetid=120179650019543638&cadevice=c&gclid=Cj0KCQjw24nNBRChARIsALldLD0RZb-nYYKOoe52_lIzut84VQ406pw9AatsMu2TGjtjIT117rR1mx0aAoOwEALw_wcB

I’m happy to help further over the phone at https://www.6ya.com/expert/donald_f2ed37026a3ac881

Google "sigma bc 506 manual" or contact Signma:
SIGMA SPORT

I’m happy to help further over the phone at https://www.6ya.com/expert/donald_f2ed37026a3ac881

http://www.manualslib.com/manual/395732/Sigma-Sport-Bc-300.html

You should be able to use it on your indoor trainer. The Sigma will need a wheel diameter callbration to give correct readings.

Hi Enrique Aparicio...
Got to the following website and download your manual
Bud

https://docs.google.com/viewer?a=v&q=cache:PLuFdndb0jcJ:www.sigmasport.com/us/allgemein/showdatei/?download%3D1%26name%3D3_1_Manual_BC906_USA.pdf+Sigma+Bc+906+Computer+user+manual&hl=en&gl=ca&pid=bl&srcid=ADGEESjmWFy82205e8C7AUiLD8618PQdH7XiGoaPs7YDAhhfeG3hQorHFs9KtltB03XNQCqV5WSPaAO34MaLHc-wJkIms2qtdE-xgWfzDWT5gnwuRFlrKWPePpzuze_mnsV2GWoT0cqU&sig=AHIEtbQx1n_behQSle5XjQgQuTfiyesg2A

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"sigma 506 manual"

Manuafacturers usually have the manuals. sigmasports.

Get the manul...
http://www.sigmasport.com/en/service_center/produkt_support/bikecomputer/

I can not off Sigma 906. It is working but can not be closed. Please help

are you sure the polarity on the battery is right, positive side to the positive contact?