Jega
About VT8237R+/VT8237 - here (may be some interesting).
About VDDR on ASROCK 775i65g - near mosfet - resistor network RNxxx (I'm not see number on photo).
Measure voltage on one side RNxxx and on other side RNxxx. Also measure voltage on gate VDDR mosfet.
Control scheme to this mosfet (VDDR) IMHO one of the two 14-pin IC (LM324 - my fantasy) near south bridge.
Jega
About VT8237R+/VT8237 - here (may be some interesting).
About VDDR on ASROCK 775i65g - near mosfet - resistor network RNxxx (I'm not see number on photo
Measure voltage on one side RNxxx and on other side RNxxx. Also measure voltage on gate VDDR mosfet.
Control scheme to this mosfet (VDDR) IMHO one of the two 14-pin IC (LM324 - my fantasy