Cell phone disassembly

Check its back light inverter and CCFL lamps.

the inverter is the usual cause of that issue. You can get the replacement Inverter from www.tvrepairworld.com

If there is problem with an inverter or a back light, the lights will come on for about 2 seconds and then shut off.
The Sanyo DP42484 television has a problem with poor quality back lights. I had one that had three bad back lights. I replaced them and it fixed the problem. The TV now comes on and stays on.
Replacing the back lights is a very tricky problem. You have to completely disassemble the entire TV to expose the back lights. The hardest part is removing the LCD glass without damaging the very delicate ribbon cables that connect it to the rest of the TV or cracking the glass.
You then have to reassemble the television, except without the LCD glass. You can then power up the TV and see which back light are not illuminating.
The back lights are 950 mm long and 3.3 mm wide. There are 12 of them. The ends are coated in a silver paint for conductivity. They are held by metal U-shaped sockets at either end. In the middle of the length of the fluorescent tube is a C-shaped plastic support to hold up the center of the long tubes. This plastic is very brittle and breaks easily. Try to slide the tube to the side thru the plastic support. If you try to spread the support wider and pull the tube foreward, the C-shaped plastic support will break.
I searched for an exact replacement, but I was not successful. The closed I could get was 950 mm long and 3.0 mm wide with wire ends. I purchased these from http://www.ccflwarehouse.com for $25 each. Part number CC30950. I bent the wire ends back and soldered them to the metal sockets. When the 3 bad lights were replaced the Television came on and stayed on.

Phone is in silent mode. Check your owners manual or user guide for how to change out of silent mode. Try turning up the volume at the main screen, this works for Samsung phones :)

hii ppl i jus bought samsung tocco few days bak i was haviing same problem but i found out wot was wrong go in menu then select settings then phone settings then there is option on d bottom PC connections click on da select mass storage then save afta dat wen u connect ur cable to Pc it will install it self then ur ready to transfer into ur phone gud luck

Ill send you an email

One thing you could test for is a thermal-fault in the phone's circuitry. To do this, you put your phone in the fridge over-night then, turn it on the next day and try the keypads while it's still cold from the fridge. If that doesn't help and you're brave enough to venture into the inner-workings of your phone to attempt repair/cleaning, you can read my post here- keys won't work on sanyo mm 8300 phone.
Hope this helps, TechnoWolfy.

call *2 - sometimes the rep will help you over the phone and other times they will tell you to take it in to the store to have it reset.

Sounds like you locked the keypad.

I know you stated all the keys don't work, but let's give this a try.

Press the "unlock" key (the key in the upper left)

Enter your lock code (usually 0000)

Let me know if this helps.

Some local wireless stores can do this for a small fee. Try finding a wireless supply store and see if they offer this. Most phone companies won't do it because they want you to stay on their network, and/or they want you to buy their phones.