Yep, more detail would be helpful to be sure we are on the right track to help you.  Based on what I am reading, the DC plug on the end of your power pack is likely broken and it sounds like you want to solder a new one on.  Is that correct?

You get them from a shop. Or trademe .   :-)

Seriously though, trademe . You need the EXACT power pack for your model of monitor .

It's the standard dc power plug used on all Samsung monitors. I thought you guys might be familiar with it.

I have dozens of PSUs (I build my own) and just need the plug. Looks like I'll have to get the complete unit instead.

6.5 x 4.4 mm

I have a rough idea what you are referring to now, but really you need to check the exact model etc or risk (prob low chance but still there) blowing something.

Something like this any good for your Samsung Monitor DC plug?

https://nz.element14.com/multicomp/mp-205/plug-low-voltage/dp/1737264

http://www.farnell.com/datasheets/3180603.pdf

Thanks Gordy..  very close may well have done the job. I went to order a couple but they wanted $15 for delivery.

ADKM:

 

Thanks Gordy..  very close may well have done the job. I went to order a couple but they wanted $15 for delivery.

 

Your spec didn't include price.

You could try Radio Spares who offer free delivery.

i got a replacement for my monitor from an e-waste site in Auckland after the dog decided it looked like a snack.  Maybe look up a collection site and ask nicely or swap for beers!