"If the TV is in the Store Demo mode" on page 122 of http://downloadcenter.samsung.com/content/UM/201112/20111216102348708/SX5DVBEU1A-ENG.pdf
Also look for that firmware update and be sure it's up to date.
I've had a Samsung TV sitting in the cupboard for a year and took it out to use as a monitor for my PC, a few minutes after it turns on, it sometimes randomly switches off and back on. most of the time it'll get stuck in a restart loop. I don't know how to fix this? Does anyone know? http://www.samsung.com/uk/support/model/UE22D5003BWXXU

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