Sorry, the question was difficult to word. Basically I recently bought a controller board for a monitor and the DC cable I got wasn't correct. So until I get the right part, I just want to test the board and the monitor to see if they work.

When I turn it over, where the DC 12V jack is, there are 4 pads: 2x 12V and 2x Ground. Is there a way I can simply connect a red and black wire just to test?

[Here is an image to explain it further.]

photo of PCB

All I want to do is connect a red and black wire, which I will connect to step up board, as this will be powered by USB, and supply 12V. (Don't worry, I checked all the amps, and voltages first, and please don't give any alternative ways of doing this.) I just don't want to go ahead and connect two wires and cause something to break.

EDIT: Which ones do I connect to? Both of the 12v and gnd? Or a specific one?

Many thanks.

  • \$\begingroup\$ Soldering Iron ... ? \$\endgroup\$
    – brhans
    Feb 16, 2019 at 15:12
  • \$\begingroup\$ *sigh... * I realise my question probably wasn't very clear so I've edited it. I meant which ones do I connect to? One wire to both 12v and the other to both gnd. Or one wire to one 12v and one wire to one gnd? \$\endgroup\$ Feb 16, 2019 at 15:30
  • \$\begingroup\$ why should we guess without full datsheet? use 12Vdc input jack + on pin. It could be switched 12V pin for dual source \$\endgroup\$ Feb 16, 2019 at 15:46
  • \$\begingroup\$ @SunnyskyguyEE75 - Here is all I could find online: vslcd.com/specification/M.RT2281(Without%20Audio).pdf \$\endgroup\$ Feb 16, 2019 at 16:00
  • \$\begingroup\$ so all you have is RT2281 ? with what monitor? and what input? LCD uses 12V for signals and 12V for LED backlight option and some boards have onboard converter and others interface via CN2 option \$\endgroup\$ Feb 16, 2019 at 16:30

2 Answers 2


Just connect one wire to one of the 12V pad and the other wire to one of the GND pad.

Although there are 2 pads for 12V, the pads are interconnected so it doesn't matter which pad you connect to. Same applies for GND.

  • \$\begingroup\$ Some boards have torroidal coil with converter, however this PDF shows none and uses external converter \$\endgroup\$ Feb 16, 2019 at 16:38
  • \$\begingroup\$ @SunnyskyguyEE75, Thanks for the correct info, edited the answer. \$\endgroup\$ Feb 16, 2019 at 16:42
  • \$\begingroup\$ I've marked this as the answer. Thank you @SunnyskyguyEE75 and Electric_90 for your help. \$\endgroup\$ Feb 16, 2019 at 16:58
  • \$\begingroup\$ It seems to have many options for 12V input V with jumper for 5V,3.3V and LVDS may need flat ferrite CM strip on ribbon cable to improve S/N at 1920x1080p from my experience due to SMPS ripple. As I cannot see SMD CM Chokes for dual LVDS GHz signals \$\endgroup\$ Feb 16, 2019 at 17:19

do a continuity test with one probe on a known GND pad and probe the unknown pads that show which 2 pads are GND do the same with the 12V line then just solder each wire to the right pad, there might be a reson for the 2 pads but if your just wanting to see everything powers on then there shouldnt be a problem


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