PlayStation 4 (PS4) launch has been marred by reports of defective units, prompting Sony to investigate.

Sony has acknowledged that some users who bought PS4 found them to be defective or bricked and assured that these were isolated incidents and are very small in numbers. "Be assured we are investigating reported PS4 issues. The number is very small compared to shipped, we believe they are isolated incidents," tweeted Shuhei Yoshida, President of Sony Worldwide Studios.

Be assured we are investigating reported PS4 issues. The number is very small compared to shipped, we believe they are isolated incidents.

— Shuhei Yoshida (@yosp) November 14, 2013

Complaints had initially popped up on the Reddit. Later they were also seen in the reviews on Amazon and company's own support forum. One problem related to the inability of the console to stream videos to the televisions.

"I also got a defective console right out of the box. I just get the blue flashing/pulsing light on the PS4 and never turns white; no display or sound. Very disappointing in this whole mess. I don't think I've ever had a piece of electronics fail right out of the box. I tried the different methods that I found online to get it to work, but they didn't do anything. I can't even get it to boot into the safe mode. Getting my refund and going to try to get one at a local store, if any are in stock," read Julian Woodrum's review on Amazon.

Sony is taking the issue seriously and has promised to sort it out at early as possible.

"A handful of people have reported issues with their PlayStation 4 systems. This is within our expectations for a new product introduction, and the vast majority of PS4 feedback has been overwhelmingly positive. We are closely monitoring for additional reports, but we think these are isolated incidents and are on track for a great launch.

"There have been several problems reported, which leads us to believe there isn't a singular problem that could impact a broader percentage of systems. The number of affected systems represents less than .4% of shipped units to date, which is within our expectations for a new product introduction," Sony told IGN.