Get something which you can hopefully return if it doesn't solve the problem.
Sadly if I had a spare PSU I would send you it for testing!
As for the CDROM (sounds like you have a SATA CD/DVD like I do), it may be that it works because, for example, it might only use the 12V wire.
Do you have a digital camera? Some photos of the Molex-to-SATA-power adapter would be helpful. I'd be looking for photos of the Molex end (specifically the pins) and a "general" photo showing the wires which go from the Molex connector to the SATA power connector.
Naturally I can't do much (remotely) regarding checking the PSU to see if the Molex power connector you're using actually sends 12V, 5V, and 3.3V up the wires.--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.