My tablet is showing the usb symbol on the screen and will not go anywhere cannot power down or anything tried plugging to my laptop and now to the electrical plug still nothing .

Make sure it is fully charged. Hold power button down for about 10 seconds and wait if nothing comes up press power again for half a second. Still nothing? Then put it on charge, it should show that it is charging with a light of a picture on the screen. If there is no sign of charging, wait about 3 hours leave the charger connected and press the power button again for about a second and wait for it to turn on or for the picture to show it is charging appears on the screen, (make sure the charger is on and connected) . Press the power button again for another 5 seconds and wait. sometimes it takes a little while to turn on, especially if the battery is very flat. Other things to try are check the charger on another device e.g. another table or a phone if you can and try another charger on the tablet if they are compatible, (usually the same plug is o.k, check the voltage is the same. most chargers are USB 5v). It may need a more powerful charger than most small phones,. you can try plugging the USB cable into a car charger or USB 3.0 port on a computer. 2 amps is common for most tablets. Apple may be different, hard to be exact without knowing brand etc.
If all else fails see the retailer

Help! My tablet won't turn on! what do I do?! - Asus - Android ...

www.tomsguide.com/forum/id-1869519/tablet-turn.html

Oct 17, 2015 - 50 posts - ‎43 authors
We often get questions such as " My tablet has stopped charging & I have .... Maybe the case was designed badly and the power button won't ..... Something must havelocked the Memopad open and ran the battery completely down. ..... I had RCA send a replacement tablet after it happened the first time.Missing: lean

Why can't I get my RCA tablet rct6077w2 charge or turn on ...

forums.androidcentral.com > Get Help & Give Help! > Ask a Question

Oct 8, 2014 - 4 posts - ‎1 author
Screen will not light up at all. Took it to store, got brief charge there. At home, now, no indication of power.....Missing: lean

How to Calibrate Your Mac, iPhone, or iPad Battery ...

www.macblend.com/how-to-calibrate-your-mac-iphone-or-ipad-battery/

Mar 14, 2012 - The iPad and other tablets draw more current to charge quickly then a lot of other USB devices ..... Also, it's not something you should have to do frequently. ... iPad 2 will not charge shows battery in red with electrical symbol and plug symbols flashing on ..... I'd lean against trying to restore if it won't stay on.

My samsung galaxy tab wont charge at all, why? - Ask Me Fast

www.askmefast.com > ... > Charge

The fact the battery shows fully charged means nothing, the symptom is a defective battery.

Try to hold the power button down until the tablet reboots.

get it to power off total . hod the switch for 20 sec
power up .
if it wont power it up with a usb attached to computer that can trigger it to go into debug mode

have you tried turning off tablet with charger plugged in and letting it charge up. You should see a battery symbol come onto the screen with a pulsing level indicating the battery is being charged. hold in power till unit turns off then plug in charger cable into tablet and switch on charger at power point . Do not try and push power switch to power up tablet see if screen indicates charging is occurring. I have experienced this exact problem on a samsung tablet !

Plug the supplied charger in to the TP and into the wall. Then hold the power button and the button at the bottom of the screen simultaneously. After about 10 - 15 seconds the TP reboots.

Exactly 1.5 meters?

Another way to adjust the screen brightness is to hold down the Functin key (blue, Fn) and then repeatedly press the up or down arrows (which also show the symbol for screen brightness on the keys in blue.)