Dell Inspiron 3656 FX-8800P motherboard

Hello, are there any restrictions in use Dell Inspiron 3656 motherboard with FX-8800P without all Dell Inspiron 3656? I have bought on ebay a new mobo, but can't start it normaly, have the atx 24 pin - dell atx 8 pin adapter cord too, but it's does'nt give output to screen(VGA or HDMI, with igpu or dgpu), or just appears Dell logo with load line on a second, and then as other times just black screen (display says it's 1080p if HDMI and 1024p and then 600p if VGA(DVI if DGPU)). Used with second FAN on SYSfan header and without it.

P.S: for more then 3 years already have another DELL Inspiron motherbord, and using it well. That's the same mobo, but with A8-7410, without pcie x16 socket and powered like laptop from 20V power supply(or power station). Any ideas? Same RAM that works with A8-7410 board doesn't work with FX-8800P.