I picked up an Augen Gentouch 78 Android tablet the second that I heard they even exist from, of all places, K-Mart. I guess I was lucky to find one in stock on August 10th since they were apparently in such high demand.
Now, from reading forums and reviews online before hand, I knew what I was getting myself in to. The thing has its share of problems, although most of the annoyances are currently incomplete software. Considering that I was wanting to build my own Android tablet/in-wall PC for over a year, I jumped on this because of it’s low price.
I decided to crack the case open to see exactly what was on the inside, and to see how easy it would be to hack should I decide to add functionality to it. After struggling with those pesky, fragile plastic clips, I finally got the back off (click any picture for large size):
As can be seen, I guess I got lucky and received a 2100mAh battery. With the version 3 Augen update, my battery indicator no longer goes to 100%, but it still seems to hold a charge for a good 4+ hours of moderate use.
The main board appears to be partitioned (by ground rings) into 4 sections: Wireless (top-left), Unknown (top-right), Power Supply (middle), and CPU (bottom). I tried to take notes of the markings on all the major chips.
First is the WiFi chip in the top-left. It appears to be labeled “ROCm / ATHEROS / AR610ZG-BMZD / E022410-51C /00880068 /1009 PHIL”, clearly indicating an Atheros WiFi chipset.
Next, in the power supply section, is an 8-pin IC near the power button labeled “RT8272 / GSPCCW03”. Searching indicates a high voltage buck converter. Some people indicate that the USB port is incapable of charging the 8.4V battery because USB is limited to 5V/500mA. This buck converter’s datasheet indicates an input voltage rage between 4.75V – 24V and a configurable output range of 0.92V to 15V. I didn’t do any testing (perhaps I should have), but it’s quite possible to speculate that they could be boosting the USB voltage levels here to (attempt to) charge the battery. My suspicion is this: If the battery typically only lasts 4 hours on a 2100mAh battery, that tells me the unit probably draws about 525mA during operation. That’s clearly over USB’s limit of 500mA, which would explain extended battery life, but not actually charging the battery. One test that should be done is to see if the battery indeed charges via USB while the unit is powered off or in sleep mode.
The far right 32-pin IC near the LCD connector appears to be labeled “ALC5621 / A4K62S1 / GA18C” which is an I2S/PCM Realtek Audio Interface Codec. The datasheet link on Realtek’s website didn’t work, but I found another copy and uploaded it here: ALC5621. The datasheet clearly shows Microphone inputs, Line inputs, and Aux inputs, so it should be possible to add those features to this tablet (might require a driver/Android change in software to use). In particular, microphone inputs should be on pins 32, 1, 2, 4, and 5. It’d be interesting to trace these on the PCB to see what connectors they come out of (if they even route anywhere), but with careful soldering, you could probably just tap directly to the pins.
Next up is of course the CPU, which we already know is a TeleChips TCC8902. I deciphered the additional markings as “0BX / AN2D6K-CN / 1023”.
The NAND flash chip is a 16Gx8 labled “SAMSUNG 013 / K9GAG08U0M / PCB0 / YCC687AW”, which should be the advertised 2GB of flash in total.
There are two 1Gb DDR2 SRAM Hynix chips as well, labeled “hynix KOR / HY5PS1G1631C / FP-25 927A / NTHA8Z83MQ1”, which confirms 256MB of RAM total.
One chip that caught my attention was the 8-pin IC near the RAM. It is marked as “AT88SC / 0104CA / U 1016” which indicates an Atmel Secure CryptoMemory chip. Could this be utilized by a future update from Augen to lock us out of custom Android images via the bootloader? Is it intended to allow for a SIM card to be added? Is it intended for some form of DRM? It’d be interesting to see how this chip is utilized now, and in the future with more updates. As of now, Augen has been quite generous at keeping this device developer-friendly and hackable.
The three crystals by the CPU I couldn’t figure out. Their markings are, from left to right:
- “NSK L
As can be seen below, the bottom side of the mainboard just contains passive components, nothing interesting. Also, there is another PCB that is not utilized whatsoever. This PCB is labeled “MID 810-LCD-V4”. It even appears that the resistive touch interface was patched to bypass this board.
And finally, I took a photo of the sticker on the backside of the LCD. The sticker reads “HLY070ML245-12A / 10072901719”.
One extremely disappointing thing was that I saw no indication of a G sensor or accelerometer in the thing, despite the user manual indicating that one should exist for auto screen orientation. If I hear of a new batch of these coming out that does include it, I’ll seriously consider exchanging my tablet for one that does, or by finding out where it should be attached and install it myself. I’d also hope that version 2 has better soldering jobs and better quality control on the product. I’m glad I opened mine because the WiFi antenna was actually getting in the way of the stylus from a very loose screw and too much antenna cable that was badly pinched.
Update: Thanks for all the comments below. As of November, just before the K-Mart 90-day return policy expired, I returned the Tablet for a full refund. Two support tickets with Augen that were simply closed with no attempt at resolution, lack of promised and much needed updates, and false advertising on the box and in the manual regarding features meant this tablet was not worth keeping.