Upon modification of voltage to ram I am unable to post

Hi, thanks for reading this thread and trying to help.

Heres what the current situation is, I changed the ram's settings from 800 mhz to 1066 mhz and addititionally changed the voltage from 1.8 to 2.1. After finding this change made gameplay instable I reverted the settings. After I reverted the settings I couldn't get the pc to post. I have tried the ram in another computer and it works fine, also I have tried a single stick in slot one of the motherboard and that does not affect anything either. I'm not sure if this is normal, but I can start up the computer with no ram in the motherboard whatsoever. Anyway, I'm wondering if I bricked the motherboard by changing and then reverting ram voltages, thanks for any reply.

Also here are the system specs:

LG 22X DVD±R DVD Burner Black SATA Model GH22NS30 - OEM
http://www.newegg.com/Product/Prod [...] 6827136152

Western Digital Caviar Black WD6401AALS 640GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive - OEM
http://www.newegg.com/Product/Prod [...] 6822136319

Antec Three Hundred Black Steel ATX Mid Tower Computer Case - Retail
http://www.newegg.com/Product/Prod [...] 6811129042

ASUS EAH4870 DK/HTDI/1GD5 Radeon HD 4870 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail
http://www.newegg.com/Product/Prod [...] 6814121291

Sunbeam CR-CCTF 120 mm Core-Contact Freezer CPU Cooler W/TX-2 - Retail
http://www.newegg.com/Product/Prod [...] 6835207004

CORSAIR CMPSU-750TX 750W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power ... - Retail
and
GIGABYTE GA-MA790X-UD4P AM3/AM2+/AM2 AMD 790X ATX AMD Motherboard - Retail
http://www.newegg.com/Product/Comb [...] mbo.201928

AMD Phenom II X4 940 Deneb 3.0GHz Socket AM2+ 125W Quad-Core Black Edition Processor Model HDZ940XCGIBOX - Retail
and
G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model F2-8500CL5D-4GBPK - Retail
http://www.newegg.com/Product/Comb [...] mbo.201928