Quincy Phillip raided a store room for laptops, mobile phones, tablet devices and Apple watches before selling them online.
READ: Spice Girl Mel B gives girl power to women in Yorkshire fleeing domestic abusePhillip was caught when he was challenged by staff at the Victoria Gate store in Leeds as he put a power supply cable into his staff locker.
The 37-year-old immediately admitted that the cable was for a laptop he had already stolen.
Phillip's home on Nunnington View, Armley, Leeds, was searched and 19 mobile phones, six tablets, 11 Apple watches and two hard drives were recovered.
Investigations then revealed Phillip had sold more stolen items on a second hand electrical retail website.
Louise Pryke said goods worth a total of £40,688 were stolen.
Items worth £11,147 had not been recovered.
Mrs Pryke said: "In interview the defendant gave full admissions.
"He said he stole because he believed there was a CCTV black spot.
"He admitted that he was motivated by greed."
READ: How 'Shags' helped this Yorkshire man win CountdownPhillip pleaded guilty to two offences of theft.
Simon Alexander, mitigating, said: "He feels guilt, shame and remorse over the way that he behaved."
Mr Alexander said Phillip had dropped out of university and began working in the retail sector, selling mobile phones in Huddersfield.
He said Phillip got the job at the John Lewis store in Leeds when it opened in 2016.
The barrister added: "He feels a massive sense of sadness about the way his conduct led him to lose that job.
"He feels like he has lost part of his family."
READ: Multi-millionaire farmer crushed to death after his dog knocked a lever in his tractorDescribing the offending he said: "At the end of the month there was a shortfall between his income and expenditure and he would take things from the store room and sell them to make up that shortfall."
Phillip was given a 12-month prison sentence, suspended for 18 months.
He was also ordered to do 280 hours of unpaid work and pay £2,000 compensation to John Lewis.