Hello!
Please help me.
I'm have MikroTik OmniTIK U-5HnD and MikroTik hEX S (RB760iGS).
Omnitik powered throw injector MikroTik OmniTIK U-5HnD.
I'm fail and connect data end injector in PoE port on hEX S. On hEX S PoE mode in force on.
After this Omnitik not turn on.

Is it possible to repair Omnitik?
Can I give you some other advice?

You don't need power injector between hEX S and OmniTik if you connect OmniTik to ethernet port 5 of hEX S (which is PoE out capable). Power adapter, supplied with hEX S (24 V, 1.2A) should be good to power both devices (each consumes max 11W, combined 22W or 0.9A @ 24V).

You don't need power injector between hEX S and OmniTik if you connect OmniTik to ethernet port 5 of hEX S (which is PoE out capable). Power adapter, supplied with hEX S (24 V, 1.2A) should be good to power both devices (each consumes max 11W, combined 22W or 0.9A @ 24V).

I know this, the question is how to restore the device

Ah, now I understand your question. I'd try to use the PoE injector to rule out possibility that hEX S doesn't provide power on PoE out ethernet port. I'm not familiar with OmniTik, but photographs indicate that there is a power status LED.
If OmniTik is bricked, you can try to unbrick it (Netinstall) while powering it via PoE injector.