Four letter phat broken leds?

My 4 letter phat has some non-working leds. It’s just the 2 on the left. Is there anything I can do to diagnose the issue before asking for a replacement?

Here’s the soldering on the back:

nasty looking solder job, looks like you need to turn up the heat ,not enough solder paste used ? ,you shouldn’t see all that brass

I agree with Jack, most likely a soldering issue.
Have a look at this and see if it helps.

Thanks both of you, a resoldering has fixed it.

great work ,enjoy its a neat little phat

Ditto to what Jack said. =)