SamyGO

I hope someone can help with my problem.

I'm a noob when it comes to TV hacking but more experienced with phones. Anyway, before starting I have aquired (from ebay) an ex-link cable/adapter based around a CP2102 chip.
I believe this is a USB to TTL adapter and it has standard output pins RST, 3V3, 5V, TXD, RXD GND.
Using the loose wire cores which came with the adapter I have managed to connect to my Samsung TV successfully to receive, but not to transmit.
I have connected the cores up as detailed in the Samygo wiki and initially nothing would work (I had the RXD of the TV connected to the TXD of the USB adapter and vice versa). When I connected the it the other way around (TXD of TV to TXD of adapter), then it started to receive a serial stream of data (at 115200 baud and as per the other settings detailed in the Samygo wiki). Consequently I connected the RXD of TV to the RXD of the adapter to tried to transmit. I cannot get the TV to accept any commands and I have tried Putty, Hyperterminal and a number of other serial comms tools. None have worked. I have read many sites where people have slightly different setting in the TV to that stated in the wiki.
In any event I have tried all of these settings e,g,
Always I need to have RS-232 mode to "Debug" to get it to work, as expected. However other settings I have read to try are Hotel Mode - tried both "on" and "off". Also Watchdog - also tried both "on" and "off" Still nothing works.
To test the adapter, i have connected the TXD pin to the RXD pin and I can successfully transmit and receive data fine.

I have spent many hours searching the net and this forum about what the problem could be but I have now almost given up - I can't get the TV to accept anything.
I'm getting to the point of considering making changes to the TV without having a working ex-link cable - all I'm interested in doing initially is to root the TV via the instructions listed at
http://wiki.samygo.tv/index.php5/Rootin ... cpu_models. What are the risks of bricking your TV if you only wish to do this?
My firmware version is listed as "T-GASDEUC-1013.7"

I hope someone can help me.

Thanks in advance

If you don`t transmit anything to TV, but you can see the debug, probably:
1. your tx pin is soldered to wrong contact.
2. cable`s tx pin wire is broken
3. your vga part pinout is wrong: if you connect GND to tx and tx to GND you also get the signal! Check triple: cable loopback, vga pinout.

Thanks for the quick reply.
I haven't done any soldering. I am using a VGA cable.
I tried to attach photos but it hasnt worked. The connections are as follows:

VGA connector pin 4 <> white wire <> TXD at USB adapter
VGA connector pin 9 <> black wire <> GND at USB adapter
VGA connector pin 11 <> blue wire <> RXD at USB adapter

(as per photo shown in http://wiki.samygo.tv/index.php5/File:VGA-Exlink.jpg)

Strangely I still get serial data from tv if I only connect pin 4 of VGA to TX of adapter.

Sorry for my misunderstanding but are you suggesting that I swap the connections of the TX and GND wires at the usb adapter
Also what is triple cable loopback vga pinout? I've done a Google search which didn't come up with anything.
Thanks

Sorry for all the questions

how do you detect tx, rx and gnd of your cable? by wire color? Wrong approach, because colors may differ from cable to cable.

Loopback test: make short circuit between tx and rx of cable and open connection like you did that before. Try to input any text. If you see what you type - cable is ok. If not - something is wrong with cable/connection settings.

Sorry the wire colours are the loose wire connectors i am using to connect the vga connector to the usb adapter (i.e. the colours don't matter).
I have reduced the photos and and attached them to explain my setup. As below:
I have tested the cable via loopback (connecting pin 4 to pin 11 at the other end of the VGA cable) and it works ok.
If i leave only the white wire connected the serial data is still received from the tv, as below:
Is it possible that pin 11 on my TV is not the correct receive pin? Do you know if it would damage anything if I tried connecting it to different pins?
Thanks

Is that really 11 pin blue wire is connected to? not 12?

Is your vga-vga cable ok? Are you sure the 11 pin is not connected to any other pins inside the connector of vga cable? You should try to connect without this cable, because i think this is your problem.

Yes, definitely pin 11 - the one in the bottom left corner of the connector. I checked the cable with a multimeter and it is a straight through connection i.e.pin 11 to pin 11 and it is not connected to any other pin either.
I originally thought the problem may be the VGA cable but my cable tests indicate that it should still work.
I think i will do what you have suggested and buy a vga connector and solder it up instead. Maybe the length of the cable is causing a problem somehow.
Do you know if it is always pin 11 from the TV perspective?
Thanks very much for your suggestions

ive just bougt one of those adapters - noticed that my pc has a vga output, can i access tdm just by hooking up vga cable from tv to pc.

You'll get no echo of what you type in unless you entered the proper codes to unlock the TDM. maybe your cable is ok ?

@neil75 : you have to use the ex link cable , PC vga output is useless in this case

ok thanks - to confirm then, the usb to ttl connection to a vga cable is all that is needed to connect to the tdm ?