Help with a LK204-25-PC my friend gave to me

fusionnv · Post by **fusionnv** » Mon Sep 26, 2005 9:29 pm

My friend decided he didn't want to mod anymore and gave me his LK-204-25-PC special edition LCD. The only cable I got was a serial cable that attaches to the thing. Now I did a search and I can use a USB to serial convertor to use USB instead of Serial because my mobo doesn't have any. That is a simple $10 fix. Now can I use the $7.49 fix of a

Communication and Power Cable from the matrix orbital site.
Straight through serial communication and 5V power cable. This cable can be used with any MOS or LK/VK/PK display to power and communicate through the 4pin SIP header. (From the pic, I am not sure how it connects to the power and serial)

I want to elimate extra wires, so can I use this to power the LCD thru USB thru the serial convertor or am I asking for trouble esp. if I start to use the GPO to control some Cold Cats, LEDs, and fans.

Tom · Post by **Tom** » Tue Sep 27, 2005 10:50 am

Hi fusionnv,

Thank you for posting on the forum.

You can also power the unit via the serial port, so if your usb port can power up the display, you won't need to get the extra cable. The picture below will illustrate what you need to for power via the serial connector. You will also need to plug in an unmodified power connector to turn on the backlight.

The power and communication cable is for power and communications via the 4 pin power connector, but you are not able to communicate via the 4 pin power on your model of display because of the age of the display.

If you have anymore questions or concerns, please feel free to post them.

Best Regards,

fusionnv · Post by **fusionnv** » Wed Sep 28, 2005 5:40 pm

Cool, that is super good news. I can just solder pin1 and the usb convertor to Serial will do the rest. How I have a question about the GPO. The serial power will be able to handle Cold Cat lights and fans? Also do you have any documents on how big of a register and which side is +/-. I tried searching on Bit-tech but all those links are dead now.

Tom · Post by **Tom** » Thu Sep 29, 2005 9:33 am

You will still need to plug in the unmodified to power up the GPOs too. They can handle the Cold Cathode lights, depending on the light being less than the specified power rating at a maximum of 12V 750mA. If you want a copy of the manual, please email me at tlam@matrixorbital.ca , and I will send you one.

Best Regards,

fusionnv · Post by **fusionnv** » Thu Sep 29, 2005 3:14 pm

Tom wrote:You will still need to plug in the unmodified to power up the GPOs too. They can handle the Cold Cathode lights, depending on the light being less than the specified power rating at a maximum of 12V 750mA. If you want a copy of the manual, please email me at tlam@matrixorbital.ca , and I will send you one.

Best Regards,

Ok after reading thru the manual. I think I have one last set of questions. The LCD is not idiot proof so I don't want to blow it up esp since it was free.

1) The unit is suppose to use modified 12V ? or do I have to do both the 5v through the serial and 12v thru the modified power.

2) I assume that on the GPO all the pins on the right side odd number pins are - and all the left side all the pins are +.

3) I see there is 26 pins in the GPO area with the diagram in the manaul. Does this mean there is ( 8 ) 12v (Pins 1-16) , and ( 2 ) 5v (Pins 17-20). and the rest shouldn't be used?

Tom · Post by **Tom** » Thu Sep 29, 2005 3:56 pm

fusionnv,

1) You will need to plug in an unmodified floppy power cable, which is the same cable coming from your pc's power supply.

2) On the GPO, the left side is the + and the right side is -.

3) There is 8 - 12V GPOs. The rest are 5V outputs for whatever you desire, but you don't need to use them.

I hope this clarifies things.

If you have anymore questions or concerns, please feel free to contact me.

Best Regards,