The Acer Iconia A500 Android tablet contains the following components, which should be visible in the photos below:
NVidia Tegra T20-HP-A3 CPU (part # 12828140 1107A3) Broadcom BCM4751 GPS receiver Atmel mXT1386 touchscreen controller module (total of four chips) Azurewave AW-NH611 WiFi/Bluetooth/FM combo chip Elipda B8132B2PB DRAM SanDisk SDIN4C2 NAND flash Texas Instruments TPS658621C power control ISL6251 battery charge controller
Here are the steps necessary to teardown the Acer Iconia A500 Android tablet.
Begin by separating the case – the easiest place to start is under the removable cover for the SD card slot. Use a spudger if you have one, or if you’re a cheapskate like me, a heavy guitar pick works pretty well too. Gently pry under the seam and work your way around the case until it comes into two separate pieces.
Here’s the Gibson Heavy acting as a spudger – you can get between the two sides of the case and gently unclip a number of places where the case clips together:
Yay! The case is apart. Set the back aside, and we’ll concentrate on the remaining section that contains the motherboard, battery and display (shown on the left in the photo below).
Here’s a few parts of the device identified – we won’t be talking about those much any more:
You’ll notice that the motherboard has a number of metal “cans” covering a large amount of real estate. Those are there for radio frequency (RF) shielding. We’ll take a look underneath them soon; in the meantime here’s some details while they are still intact. You also may notice there’s a big empty chunk of space in the middle of the device – this is a WiFi-only version of the device, no GSM (3G or 4G). I assume that big honkin’ space is for a GSM controller card, and there’s a bit of space near the edge of the case where the 3G/4G antennae would go.
Any time you see a tiny co-ax lead with a U.Fl connector, as in the photo above near the designator “ANT5,” you know that is some kind of RF connection – WiFi, Bluetooth, cellular, or such. In the case of “ANT5,” it’s the lead to the 2.4 GHz antenna that’s shared by the WiFi and Bluetooth.
Another U.Fl connector with a co-ax lead (above) … this time it’s “ANT3” and it’s for the GPS.
Below is a close-up of the ribbon connectors that lead from the external USB host/slave connectors (on the upper right of the photo) to the controller:
Next is a look at the touchscreen controller:
I mentioned that the Azurewave controller provides both WiFi (b/g/n, with only a single n stream provided) and Bluetooth (3.0+HS and SoftAP). It operates only in the 2.4GHz range, and a single fractal antenna (shown below) supports both interfaces. It uses the Broadcom BCM432x WiFi driver.
Here’s where the other end of that co-ax ends up, our old friend “ANT5” right next to the can where the Azurewave chip lives:
And here’s another look at the GPS antenna “ANT3”, next to a can S4 that covers the Broadcom GPS receiver:
A couple of close-ups of the Atmel touchscreen controller are next:
OK, now it’s time to start stripping off the RF cans to see what lies beneath. None of the cans were soldered on, so they can all be removed by gently prying. They will bend as they are coming off, so we’ll need to reshape them to replace them when the time comes. Otherwise we could have RF emanations that could interfere with the device’s operation, or the operation of other devices nearby. Don’t want your plane to plummet into the ocean, do you?
Above is the Azurewave WiFi/BT/FM chip shown with the can removed. I didn’t find any sort of FM antenna, so I’m assuming that part of the chip simply isn’t functional on this tablet.
Below is a look at some of the other circuitry on the top side of the motherboard, including the battery charge controller chip:
And now let’s revisit S4 and remove the can from above the Broadcom GPS receiver:
There are a number of roundwire and flatwire connectors that we need to disconnect as we move forward. Shown below is a Low Voltage Data Signaling (LVDS) connector that tunnels under the battery. Note the shiny silver tape – this is a flexible type of RF shielding. When we carefully peel it back, we can see the connector. When reassembling the device, be careful that this metal mesh tape makes a good connection with the copper pads on the circuit board, to ensure proper shielding of the devices.
Observant viewers will have noticed “ANT1” and “ANT2” in the above photo, both unpopulated. I assume these are for the missing GSM module. I never did find an “ANT4” however.
Ok the final can to be removed is the large one that covers the Tegra CPU, Elipda DRAM and the LVDS controller:
A couple of Kingstate microphones can be disconnected (MIC1 and MIC2) and popped out – I didn’t find these part numbers on Kingstate’s web site, however:
Now we can remove the four screws holding the battery in place, and remove the battery.
Here’s what the other side of the battery looks like:
Now we’re going to disconnect the final connector to the motherboard. This one is also wrapped in metal mesh tape – in fact it has no backshell at all, it just seems to be held together with that tape. So I pried it apart gently one side of the connector at a time.
There are three flat ribbon cables that also need to come off – the trick to these is to click upwards the black part of the connector, then the ribbon comes right out. They are kind of like those old zero-insertion-force connectors that Pentium CPUs used to use. The black part pivots in place, and when clicked up, releases the ribbon connector. Here’s one, shown in the released position …
… and another, shown still in the secured position:
OK if all our connectors are undone, we can separate the motherboard from the rest of the case now, by removing four screws (including one with a black finish that is on metal tape next to the charging circuitry):
All that’s left now in the case are the touchscreen display, USB controllers and various other input/output devices … not much point in taking those apart:
What we are interested in is the motherboard – here’s another shot of the top, then one of the rear side with the can still in place, then a couple with the can removed (sorry about the blurryness):
You can see the SanDisk NAND flash that acts as the “default” /sdcard directory when you don’t have an external micro SD plugged in. This will be Android’s default external storage directory.
Let’s have a closer look at the CPU on the front of the motherboard. I’ve scraped away some of the thermal gel that was left behind when I separated the can:
OK well that’s about it for dissection. Time to put it back together … the keys are to be gentle, make sure all the connectors are reconnected, RF cans back in place, and the circuit boards lined up properly with the case, then snap the case back together. Here, you can see how the two halves go together:
And, a final smoke check, make sure it boots and all the peripherals still work:
All done! Hope you found this helpful.