LK204-25 Stuck at Startup Display Matrix Orbital

Raquel · Post by **Raquel** » Wed May 31, 2006 3:42 pm

Hi Erv,

I am posting a picture of how to get the LK204-25 PCB 1.23 to TTL levels, and as I see it, yours is at TTL levels.

To get the board to RS232 levels, undo the comments, ie. Connect the two traces that you can see obviously severed in your board, and unsolder the solder jumps that are soldered in your board.

erv100 · Post by **erv100** » Wed May 31, 2006 4:37 pm

I bridged the two lines (vertically). I had not to unsolder because that was allready unsoldered. (This is a new device I just got today). Effect: No characters displayed anymore (all blank at power up and thereafter).

Raquel · Post by **Raquel** » Wed May 31, 2006 4:50 pm

Hi Erv,

Okay, let's go back a bit. The picture you sent has the 2 solder jumps jumpered, it also has the two traces severed. When a board is such, it is configured in TTL.

Unless otherwise requested TTL level settings, the board should be in RS232 level settings when it leaves the factory, which means that the 2 solder jumps are not soldered and the traces are not severed. I wonder about your new board, how it has the traces severed but not have the solder jumps soldered/jumpered.

And also, may I ask how you are communicating with the board? Since you wanted to put the board in RS232 levels, you must somehow be communicating via a PC or a host controller that has some level translation to RS232?

erv100 · Post by **erv100** » Wed May 31, 2006 5:12 pm

OK. I have interpreted the upper pads differently. Thought there was a horizonal link. Now I got it , have unsoldered the two pads and .. YES it works now! It seems to me though that this 'new' board was not really new when I got it.

Your support was highly appreciated. It is now 1 AM time to leave.

Thanks
Erv

Raquel · Post by **Raquel** » Wed May 31, 2006 5:18 pm

Hi Erv,

I am glad to hear that things are now better. Have a good night, or whatever's left of the night.