So, one of the bigger perks associated with working in a multimedia research lab is that you’re surrounded by a ton of multimedia equipment. After a long day of fighting with an LTE simulator, its nice to have a 65″ 3DTV to watch a film on after hours.
Sadly a few weeks ago one of our passive 3DTVs in the lab gave up on us. This was regularly used for subjective assessments by other researchers and, after being deemed beyond economic repair, was promptly replaced to avoid delays to anybodies work. That left the old JVC sitting around gathering dust. Nasser (friend and colleague) and I decided, even purely as a learning exercise, we would see what was the matter for ourselves. So we popped it on a trolley and up to the electronic engineering labs (another perk of working at a university!).
The symptoms of the LCD TV were typical of a backlight issue. The screen would show up for a few seconds when first turned on, then go black. This was a CCFL backlit TV, not LED, so caution must be used when investigating the backlight circuitry due to very high voltage. Without any kind of service manual or circuit diagram being available anywhere online, our ability to track down faults was severely limited. We used reason and logic to deduce that the power supply board was serviceable, and the issue lead more and more to the CCFL tubes which had done their fair share of hours.
In order to check if the LCD was still functional, we used the torch trick and could see the screen responding to changing of the input source.
An Idea! Lets convert the CCFL backlight to LED! On a 46″ 3DTV!
After a search online it was clear we were the first to attempt this on a TV (or at least post online about it!) so we were on our own. We set to stripping down the old backlight assembly which essentially required splitting the LCD + Diffuser + backlight sandwich. I feel this stage is probably best shown in pictures for anybody interested.
More updates to come. Stay Tuned.