Apex digital LD4688 turns on then screen goes black

T'Con board fault. If you wish to get some details; check the site linked here. Pull up older posts.
http://electro-medical.blogspot.com/
http://electronicshelponline.blogspot.com/
Faults & possible causes to LCD screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD screen are similar, irrespective of its brand and screen size.

Check and replace damaged component/s at its horizontal scan output section circuit. Check the LOT (Line Output Transformer) too for damage. Replace the horizontal scan output transistor. Check the input voltage to LOT. If the voltage is absent check the feeder resistor; if any. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electronicshelponline.blogspot.com/
Type in this key phrase " my service table today " in the search box at the top right of the display window of the home page, to get gathered some pages which has the details of practical experiences to the author of that site.

Sounds like a vertical scan out section ciruit problem. Contact any service technician.
Gopakumar Gopalan Google

http://www.retrevo.com
Try this link.

No It has only analog tuner.

Hi there,

On the acer one hold down the blue Fn button and look for a screen like caracter that is blue too. I think its F5 or F6. Press one of those while the Fn is holded down.

Good luck.

replace backlight inverter.

The set is slow to respond but you must have a clear shot at the lower right corner of the set. That is where the signal is received. Our sofa cushiopn sometimes gets in the way and must be moved. When a signal is received the blue light comes on.

I install dish network. i have tried all versions of dish remotes, . the only one that works is Dish Network 21.0 Learning Remote. it will work with all dish products and i have programed it for this tv apex ld4688 hd and it works great.here is a link for the manual on how to use.
http://www.satelliteguys.us/dish-network-forum/158496-dish-network-21-0-learning-remote.html

Not a home repair take it to a repair store.