cannot get custom PC to output signal! Terp PC builders, HELP ME PLEASE!

Hello. Several months ago I had a friend convince me to build a PC. Unfortunately, it has been a mess from the get-go and has yet to work. I took it to a repair shop, had several parts swapped, and now the store can't seem to get it to output a signal either. Am I missing something? Are my parts compatible? If not, what can I do if seemingly no one can figure out what's wrong with it? Sell the parts?

parts list:

• 1 x Intel Core i7-7700K Kaby Lake Quad-Core 4.2 GHz LGA 1151 91W BX80677I77700K Desktop Processor

• 1x ASRock Z270 Extreme 4 LGA 1151 Intel Z270 HDMI SATA 6Gb/s USB 3.1 ATX Motherboards - Intel

• 1x EVGA SuperNOVA 750 G3, 220-G3-0750-X1, 80+ GOLD, 750W Fully Modular, EVGA ECO Mode with New HDB Fan

• 1x Cooler Master Hyper 212 EVO - CPU Cooler with 120mm PWM Fan

• 1x MSI GeForce GTX 1070 DirectX 12 GTX 1070 GAMING 8G 8GB 256-Bit GDDR5 PCI Express 3.0 x16 HDCP Ready SLI Support ATX Video Card

• 2x G.SKILL Ripjaws V Series 16GB 288-Pin DDR4 SDRAM DDR4 3200 (PC4 25600) Intel Z270 Platform Desktop Memory Model

• 1x Phanteks Eclipse P400 PH-EC416PTG_BK Satin Black Tempered Glass/Steel ATX Mid Tower Computer Case

• 1x PNY CS1311 240GB 2.5” SATA III Internal Solid State Drive

Any help would be appreciated. This was supposed to be a graduation gift to myself and at this point I'm really just considering taking a huge loss to sell the parts. Anyone that has experience building PC's that is willing to take a look for me, I'd happily pay for services. I live close to campus.