you have to be referring to that ONE guy that came in Tuesday, made a big post about burnt fingers, and subsequently has not returned for 2 days? (he still has a 1 post count)
1) that's not "people" ... that's 1 noob.
2) he said he had a 32ch transmitter... there are no plug and play cables for any 32 channel transmitters. The only 5.8Ghz, 32ch transmitters I'm aware of are the not-real-Boscam TS8xx series which do NOT have the standard Boscam pin configuration... even if there are some I'm not aware of, the PnP cables are only for the ImmersionRC 600mW (which is 7ch) or a real Boscam TS351, TS352, or TS353 (8ch each)
so one person vs the hundreds if not thousands on this forum alone having no issues when they pair the right cable with the right transmitter... I'm going with some sort of user error on that one.
Just like that guy, you don't mention exactly which transmitter you have
and while you're at it, how about a link to the exact cable you bought?
your question: "how can I check it" - easy... understand the path the power and signal are supposed to follow, and just follow the wires while comparing them to the wiring diagrams of your equipment. Whatever transmitter you get should have a wiring diagram (or it's easy to look up online) ... just make sure the cable you install has the proper pin configuration. Most importantly is the power... there's red (power) and black (ground)... make sure they go into the proper power/ground plugs on the transmitter.