afaik... you can flash it back as long as you can still access bootloader/loader/flashmode for the rk device.. good thing you have an original firmware, now there are different types of firmware, i think, in the researches ive done here some types that i still remember are Zip (Edify), FW (uhm, Firmware? i think this is the true Firmware file), and Image/Images in IMG format, (multiple images. i think these are dump / backup files, and a Orig.img which is also flashable in batchtools, right?)
-if you have the original.img from the vendor (Image, if you can take a peek in the content, go check if it has something like a res folder or other imgs inside) you can just simply flash it back, as long as your device can boot to loader/flashmode. can be flashed by rkflash,rkbatch(not really sure), rkflash_tools or any other compatible flasher, double check the start address or device partition parameters in the flasher, if there was any, this was the first major error that i did to my tablet, flashed a wrong cwm recovery in the incorrect start address. rkbatchtool doesnot have these i think but rkflashtool does
-if you have the original.zip from the vendor, you can put this file in the root of a external or internal sd(Adb push to copy in the internal).. You must be able to access the recovery mode for your device. You can adb remount, adb push orig.zip /mnt/sdcard or external_sd or somewhere else where you can push file. then apply update or restore from zip package, to avoid errors and make a clean update/restore, wipe data and cache before doing the steps. more option / tools / command / advanced and much easier if you have already installed a WORKING CWM.
-- you can access recovery mode by adb , removing/clearing the system partition(Not really sure but happened to me, boot priorities of my device is system - recovery - bootloader/flash), or by button combination, which is usually the vol+ and power, must do the combination while the device is off and hold it for a few seconds...
-if you have an original.fw, use batchtools to flash it back, the most easiest way for me to flash a fw for a rk device, but also the most difficult to find rom compatible, Cant use backup.img or tar or dump.imgs here, it checks for a certain structure.
-if update.img or update.zip from the vendor, you can try pushing/copying it to the root folder of your sdcard or external_sd. push it in the /mnt folder
im currently on my 5th day in my android venture, and will be around, im still trying to fix some remaining errors in the dumps of my unpopular unsupported device.

I will be around if i can help,
oh and if you cant detect your device, try these...
-double check then make a final check that you have installed the flash driver for your device, usually attached with the flashtools. and make sure that no unknown device or device with no drivers in windows.
-Reset button then plug, wait for a few seconds, scan hardware changes,,, if still not...
-Hold Reset Button, then plug it to computer, and if the device led is off or does not turn on, press/hold the power button, this will light up the leds, but if you dont release the reset button before you release the power, it will be turned off again.
-if all else fail, you will have to look for the nand chip, and pray that it is a hynix one, especially the h27ucg8t2atr or hynix 27 8gb, other variants or hynix nand can still be entered to mask rom mod. if you are lucky, you might find a jumper/switch on the board that will make it automatically a factory built device or masked rom mode,. This is how i revived my tablet, after fully bricking it by nand idb erase + flashing incorrect parameter
and leaving my device with no loader no recovery no system no kernel

)
EDIT:
i've just checked the link, and i saw that you are fully bricked unreadable, you might need to open up your tablet, try first some of what ive written, until you are 100% or almost 100% sure that you cannot detect the device in any way,
use an rk flashtool, especially made for rk29 devices i think, 1.37 is the highest version i've found but i am using a 1.35 moded by finless to flash.
extract you original fw, into multiple images,
most important parts are
Loader.bin
Parameter
kernel.img
i think even without these other images you can now start detecting your device in usb, reinstall the drivers, as it will be a fresh device out of the box after reloading the loader.bin find a compatible rk2918Loader.bin. use our bestfriend, google,
boot.img
recovery.img
system.img
my device are also detectable in dead/off state where the device is turned off, (android debug tool compat device)
i think you can adb reboot bootloader here
if you can open up and makesure that your nandchip is the same as what i am talking about in the previous step regarding the nand, You can follow finless steps in enteing masked rom, or follow these for a shorter (Actually these is pretty long already

)
0 Press reset or make sure 100% that your device is turned off
1 remove any charger/usb connector first.
2 locate the nandchip, might be close to the processor chip or edge. You can find a HYNIX, if it is a hynix nand, and the h27-model id or hy/hc-model id
if the same chip with the h27ucg8t2atr (or chip with same hardware features, NOT SPECS)
just count 8 from the top of the legs/pins of the chip in the left, (UPPER LEFT IS 1), in the position where you can normally read the letters/numbers. A magnifying glass can surely help in this process, plus with an aid of assistant,
then after you located the 8th pin, connect it to pin 9, next pin below the 8th, with any metal or tools that can short circuit the two pins. In my case, ive used a flat end precision kit (size 2.0 flat) to short circuit it, it fits in the middle of the two leg so it will be mounted and can avoid misalignment while we do this
Hold the jumper tool or keep it short circuited then insert the cable to the PC, Call your assistant if you have one,
then once you see the masked rom mode, You can release the short circuit and start flashing.
some important Facts:
Run as admin the Tools in win vista or higher just to make sure it works 100%
advice,
For safety precaution, remove any other removable device (including lcds, connected with a flex cables and power cable, memory cards, etc.
If you did all that and still not able to revive your device, (ive done most of what i've typed and revived mine, WITHOUT ORIG FW from the Factory or any other firmware file for my device, CREDITS to LEONAS btw because he made a CWM recovery for my device from my dump of recovery.img and provided some assistance, i have 1 romdump and 1 nandroid/cwm backup from a working and a semi working state.)
last option, (based on my logic, just a simple theory,) Go buy a new compatible nand for your device, better yet, buy a similar and read the manual, especially the pin shorting if it has any way to fool your board & procie or cpu that you have no NAND installed. If no option to do that , might be able to do a workaround with unsoldering the nand, or power legs of nand, then make it get detected with no nand then Support it with you hand, to fully connect the legs, and make a flash to it... just hope that it works, didnt get to the point where i had to test my theory....
Hope you fix your tablet soon....
---------- Post added 2nd October 2013 at 12:20 AM ---------- Previous post was 1st October 2013 at 11:41 PM ----------
ooops didnt notice that it is a month old unupdated thread but anyways this will be added to the search engines and will still be available if someone searched for the same keywords, hope that these infos help those who are in need.
---------- Post added at 12:32 AM ---------- Previous post was at 12:20 AM ----------
Try any ways to connect your device to the pc or any other android with usb on the go, or maybe yours have a usb on the go,
Then use adb tools
adb reboot bootloader,
or
if you had use a flasher, you can normally insert and turn on your device it will be pink in rkbatch tools or rock usb mass storage on rkflashtools then there is a button to reboot to flash mode
or
you can also connect to the pc and adb thru wifi,
or
i dont think you can flash it without making it connect to your pc in the most simple way, (wifi needs configs, cant flash thru wifi when bricked. Ethernet might work but may not too, just try anything and everything, )
you might be able to connect with ethernet, try adb listening to the port and ip of the device (Port is the allowed port for the device, specified in the system/build.prop if i am not mistaken, and you can also try default port. check in the router if any ip will be given for the device in the DHCP. ENABLE DHCP in the router first to make the device auto fetch ip from router, or if device have static ip , then try connecting thru it
you can try to look for a nand connector to pc, unsolder the nand from your device, connect to pc then mount it flash the rom, then resolder / remount it back to the device, (these are just my imagination i dont have any ideas how much fact is in there

)
try usb M - usb M connector, i know that normal pc can communucate with that kind of cable, nor very sure though,