MLais M52 Teardown

I got stuck trying to swap SIMs and decided the put on engineers that delivered this bargain machine for £85 had not tested this and that the pins had some how bent to deny me access. As will become apparent it was the metal girdle pressing the SIM card against the contacts that was the culprit, or, more specifically, a wayward curl of plastic from the SIM itself blocking (easily removed with a sharp blade).

Anyway, on with the teardown:

The boards are visible after the usual procedure to remove the back plastic:

1. battery out, then hold the power to short any residual charge
2. undo screws (about a dozen on this monster) including one with a security sticker on it, they can be tight so have a good bit
3. nails or if they matter plastic like a toothpick

Both camera modules are instantly accessible and should their interface ever become standardised (#ahem# #project ara# #ahem#) we could find drop in replacements. I've been looking at many camera modules, for many uses, mostly for quad copters, and sadly nothing is standardised at the level of integration of flagship phone cameras.

Got your cameras out and away from dust and harm? Good. These are the locations (drawn in mauve) of the electrical connections that must be unfastened for the circuit board to be levered out.

That's showing them undone. I should go through them one by one so you needn't sweat it about breaking any when you try. Does anyone still do this or is it just the Know-How team at PC World when they grade their computers refurbished? Here goes, clockwise from the power button at the bottom left.

1. Power button - tricky this as you kneed a sharp blade slid precisely along the plastic shell to lever up the flexible button. It will retain most of its stickyness and has mechanical fixation by other means.
2. Wide ribbon - flip up the black lever where the cable enters.
3. Main camera module - lift directly up applying even force if you're careful.
4. Goodix orange chip ribbon - flip the black lever at the back where it pins the ribbon.
5. Front camera - pull connector directly upwards, don't worry about the black tape on top, it isn't connected elsewhere
6. Volume button ribbon - afforded its own ribbon connector! No expense spared! Like the Goodix connector of similar size, flip the black lever from the opposite side of cable entry

Next undo the screws, again they can be tight for a mobile phone. There are 3 in the photo but I struggled for a long time prising up the PCB because another screw is hidden under the silver tape where the connector for the volume button ribbon is opened. Carefully peel the tape back, using a sharp blade for a clean initial purchase. Don't worry too much, it's quite sticky still and there isn't really an alternative. It helps keep temperatures down.

With the 4 screws removed one proceeds to lever the PCB up from the top, be very careful at the bottom because there is a broad ribbon I couldn't find a way to disconnect running behind the battery. I must record here, because it isn't in any of  my pictures, that I couldn't find how to undo this last connector, on my Lenovo teardown it's a vertical plug in connector like the two camera modules here.

This is the rear of the PCB in all its glory. The blue square is very likely masking the MT6572, I can see the beginning of an M and it is right the size and place with enough attention given to cooling. Trying to remove the blue foam leaves a layer on the chip which isn't convenient when all the while that stubborn last ribbon is the last link between PCB and phone. With more experience and motivation I'm sure I could deal with both obstacles.

The chip models might be some use to ROM developers so here they all are beginning from the front:

What's this? Behind a heatsink the inscription,
6671122.1
1510 NX
is visible (or HX or even MX)

GOODIX
GT9157
1443-B37A
147C1200
E5L 401 xxxx (or E5I)
see http://www.goodix.com/Products/touchscreen-chip-for-mobilephone/hotknot/
This is our touchscreen controller and supports a form of NFC screentouch communication called "HotKnot" (probably only with other GT9157s)

Primary camera, ribbon marking is
JAL-JBL
-A128B
(8604)

Front camera ribbon markings:
JAL-JBL-
A128F(4-8)

On The Flip Side

a radio transceiver
MEDIATEK
MT6169V
1513-AMTH
BTP2NV39

The 2Gb DDR3 ram
SAMSUNG 516
KMR820001M-B609
Some probably unique number.


Other phones with the MT6169V
Pioneer K88L
Meizu-MX4
TCL Momoda 4G

After reading some other teardowns I notice that they aren't so easy to find and the MLais is not very anti-tamper for my part. There are some metal screens I didn't try very hard to look behind but much less than on equivalent phones, though the phones listed above do tend to have many more chips than I discovered, they are a bit older, or perhaps I am missing some.