Post by jeremy on Jun 3, 2014 10:51:07 GMT -5
I was given this Dynex DX-L40-10A 1080p LCD TV From a company I liquidate equipment for. The issue with it is the standby LED would illuminate, but you could not get the set to power up via the touch buttons on the side, a remote, etc....
Some symptoms you may notice with your set would be: loud cracks from the speakers, the TV set not displaying any image, unresponsive buttons on the side of the set, and/or remote, standby LED on but set will not power on, screen illuminates black (backlights come on) but no image from the internal menu OSD or source device. All of these problems can be remedied with the same solution below:
I decided to look it up on the net first before I took it apart just to see what the common issues are with the set, and if anyone has had the same problem and possibly a solution (why not take the easy way out if its available? 
). Needless to say, most results turned up absolutely nothing useful, but a plethora of people having issues with this set. The most relavant topic I found was a set like this that had a similar power issue, not quite the same, but similar.
I later found the service manual, and in the SM it says the symptoms I am having suggests replacing the main control board of the set (the one with the HDMIs and other I/O), part 122917. It is also listed as a best seller on partstore (I wonder why? *eyeroll*)
Anyway, instead of buying another future-defective board, I went ahead with replacing ALL the capacitors on it. These have to be some of the CHEAPEST capacitors you can find anywhere... The brand is "PEACE". Too bad all they do is cause anger and hate towards the set!
Anyway, there are 8 470uf 16v, 6 220uf 16v, 3 220uf 25v, and 16 100uf 16v capacitors on this motherboard, all cheapo PEACE electrolytics. I went ahead and replaced all of them with brand new, genuine, nichicon audio grade capacitors (yeah its a huge waste of such a fine capacitor in a set like this, but really, this thing looks brand new, so I figured I would stick the whopping $15 of parts I have into it) into the main board.
Testing the old capacitors will most likely show the capacitance to be almost dead on, ESR may also be relatively close, but when there is a load on these, that's when things start to happen, and that's why they must ALL be replaced, to prevent any future failures.
The set is relatively easy to take apart, theres less than 20 screws to remove the back cover, and it just pulls right off without any effort once the screws are out, revealing the PSU, inverter, and main board.
As a recommendation; it is a good idea to recap the entire power supply as well. I have not detailed the capacitors on this board, but since you are most likely in the set at this point, you should be able to easily see the capacitor values on the PSU. The capacitors on it are just as cheap, and likely to fail as the ones on the mainboard. Replacing all the capacitors on the PSU and mainboard, with quality genuine capacitors from a reliable source (NOT EBAY SELLERS IN CHINA!) I recommend nichicon because of their very high reliability over time, they cost more than most brands, but are completely worth it if you don't want to fix the set again in the future.
That sums it up. Provided all parts were installed correctly with a decent soldering job on the connections, the set should behave like a good working set again. I hope this write-up helps those of you who were like me; hoping to find a quick fix to get your set going again!
