USB to serial cable part 2

I recently got my TP Link WR703N ultra tiny router. Neat little thing.
But what makes this small electronic piece even more neater ?
Flashing custom firmware, of course !!

So long story shorts. I successfully bricked my device. Totally. Not even failsafe was working anymore.
So I had to get access to the console via serial port.
Uncool without a proper USB2Serial cable but I remembered to have a very old mobile data cable dug deep in my hardware trash mystery chest.


The converting of the mobile cable failed because the PCB with the Prolific PL2303HX chip had no pin out printed on.

So suck it and see.
1. I made a close up shot of the board. Properly lit.

World Phone USB Data Cable for a Sony Ericsson mobile
World Phone USB Data Cable for a Sony Ericsson mobile

 

 

 

 

 

 

 

 

2. Got the datasheet for the chip (link) which is a PL-2303HX
3. Then I traced the circuits from the pins to the chip and I came up with this drawing:

Reverse engineered circuits for the PL-2303HX
Reverse engineered circuits for the PL-2303HX

 

 

 

 

 

 

From top to bottom:

BLACK (thick cable) = GND

8 / not assigned = ?
7 / yellow = ?
6 / not assigned = ?
5 / not assigned = ?
4 / black (thin cable) = RXD
3 / white = RTS_N
2 / not assigned = DTR_N
1 / blue = TXD
V 0 / red = 3.3 V

Hooking it up with the soldered serial port on the bricked device I managed to get serial console access using RealTerm.

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