I've had this problem in the past. If I load up a 2014 version of the firmware to the sj4000 it will boot up just fine. But, when I update it with the latest firmware, it boots to a blank screen with a blue light on the side...yellow light on the top.
i have a same problem. just try to upgrade my firmware for sj4000 wifi 1.5 LCD and got black screen and blue light.
I should have check this post before I started a new thread , anyway , same for me , camera was working fine then I had the clever idea of updating the firmware and now the camera is stuffed. Sent a message to support , let's see what is the solution.
If I remember correctly, then there was 2 different screen sizes for sj4000 wifi. The older one was a bit smaller and when this camera got updated to the FW that was meant for the more recent model, it resulted blank screen. Reflashing to the correct version would help.
What version did you download, and which SJ4000? In any case, I found out just today that the first batch of SJ4000s cannot update using the latest firmware and should use specific versions of it. I took the liberty of creating a new post so it can be properly tagged. Jump to the post by clicking here: Older 1.5-Inch Screen SJ4000 Series (First batch) Uses A Different Firmware