The machine didn't STORE the key, only VOL+, VOL-, SEARCH, and PR+ four keys, based on symptoms and the actual circuit, voltage pushbutton circuit this fault is caused by leakage of the key. Four buttons on the test machine, only the voltage differential across PR+ key, as shown in the figure, PR+ and the CPU{18} feet after opening, STORE features disappear, key and remote control are returned to normal, keys for new PR+, troubleshooting.
Summary: due to PR+ key leakage, CPU{13} feet of 5V voltage by resistance RK03 buck, again by PR+ key leakage resistance buck Hou, sent to CPU{18} feet voltage will below PR+ key normal work Shi sent to of voltage, CPU will the voltage for compared, determines was by Xia press of location (function), Executive phase corresponds to of function instruction STORE, thus appeared the fault.