Unbrick LG LD, LH series TV sets

If you made a bad firmware upgrade for some LG TV series, you could recover the TV with a few steps…from a  RS232 – serial console!

What you will need:

  • Hyperterminal. If you have Windows XP, you probably already have this. However, the trial version will do;
  • A serial port on your computer.
  • A Null modem cable. If you don’t have one laying around, you could make one.

So, here is what you will need:

-Two DB9 female connectors;
-A disposable USB cable with reasonable length (I found a 2 meters long one); Also, any 3 wired cable will do;
-A soldering iron for making connections;
-A steady hand.

Here is how you must wire the whole thing:

db9nulldumb_0_o

You will also need a good firmware version. You can download a good firmware for your LG Tv model, from the LG site.
Optional: A good UPS, to avoid any data loss.
Now, if you have all of that, do EXACTLY this way:

  1. Turn OFF your TV;
  2. Connect the cable on PC and on your TV;
  3. Start Hyperterminal;
  4. On the „New connection name” window just enter LG. You can use any name here, it is not important at all;
  5. On the „Connect To” window select the port you are using (I use COM1) then click on „Configure”;
  6. In the „Configure” window select:

Bit rate per second: 115200;
Data bits: 8;
Parity: none;
Stop bits: 1;
Flow Control: none.

7. Hit „Apply” then „Ok” twice.
Right now, „Hyperterminal” will wait for incoming connections. So… Let’s connect the TV!
1. Turn ON the TV and press ESC key several times. If everything goes fine, you will see „Mstar #” prompt after 5-10 seconds;
If you are lucky enough to see that prompt, type swuz then hit Enter key (you will see some HEX numbers);
2. Go to Transfer->Send file menu;
3. On „Filename” box select the correct firmware and on „Protocol” box select „Zmodem” (not „Zmodem with Crash Recovery”);
4. Hit „SEND” button and wait without touching ANYTHING else. Basically, just leave your computer for 30 min or so!

You need to wait for about 30 minutes or so for the file to be transferred. If everything goes fine, you will see a very fast-scrolling screen with EPROM informations. You don’t need to know those, but after few seconds you will see the prompt again.

Don’t do anything else than turn off your TV, unplug the serial cable, turn it back on, and all should be working with no problem!

PS:You may have to try several times to succeed the transfer. I noticed that the transfer is stuck when the monitor goes to sleep, so you better disable monitor standby. Also, don’t do anything else on your computer. If you also get stuck with transfer, just turn off your TV and carefully re-do all steps above.

 

Good Luck!

#32ld320, #ld-series, #lg, #lh-series, #service, #tv, #unbrick