New computer build, no POST, no video

[regnaseel]

New computer build, not getting video however powering up everything seems fine.

Specs :

Motherboard - Supermicro C7Z170-SQ
GPU - ASUS GTX 1050 Ti Phoenix 4GB
CPU - Intel Core i5-7500
RAM - Ballistix Sport LT Gray 4GB DDR4-2400 UDIMM
PSU - 480W

Notes :
- Have tried reseating everything.
- Have tried resetting CMOS.
- Have tried checking piece by piece to see if faulty parts (outside of mobo ofc).
- Have tried completely resetting/reseating/removing everything and restarting from scratch.
- Removing and reseating GPU along with thermal compound/heatsink.
- Back panel does not seem to be working(?), front USBs are working but back ones are not.
- Have tried running through both integrated graphics and GPU, neither worked.
- 5 short beeps + 1 long beep with RAM removed, no beeps with 1 stick of RAM placed in.
- Have tried different CPU (i7-2600 from old PC) still no video.
- Motherboard error code is either E2 or 23, unsure if reading it right/wrong.

Unsure if I have forgotten to list anything else I have tried but I've tried practically everything. Posting here as last resort before returning parts as possibly faulty.
Help is much appreciated.

EDIT : USBs on back panel are working, however DVI/VGA/HDMI ports are not...

 

[raisonjohn]

The C7Z170-SQ might not have an updated BIOS to support 7th-gen Kaby Lake CPU (i5-7500). Z170 chipsets support 6th-gen Skylake CPUs out-of-the-box (not 7th gen Kaby Lake without an updated BIOS). Try booting up with any Skylake CPU (even a Celeron G3900 or other 6th-gen CPU) and see if it works. If it boots up, update the BIOS to a version that will support the Kaby Lake CPU you have. Then you can use that i5-7500 on that Z170 motherboard of yours.

 

[raisonjohn]

Additional comment:

The "Z" chipset boards are intended for overclocking unlocked CPUs ("K" series). Since you only have an i5-7500 (non-K), you won't be able to take advantage of the Z170 mobo's features. If you decide on exchanging (either the mobo or the CPU, or both), it's best to pair the chipset and cpu to these:

Z170 motherboard -> "K"-series 6th-gen Skylake CPUs (e.g., i5-6600K or i7-6700K)
Z270 motherboard -> "K"-series 7th-gen Kaby Lake CPUs (e.g., i5-7600K or i7-7700K) or "K"-series 6th-gen Skylake CPUs
H170, B150, H110 mobos -> non-"K" 6th-gen Skylake CPUs
H270, B250 mobos -> non-"K" 7th-gen Kaby Lake CPUs or non-"K" 6th-gen Skylake CPUs

 

[DRagor]

You put 1155 CPU (i7-2600) into 1151 socket? And expect it to work?