sony amplifier str k750

[alimaj]

Hi I have this amplifier hoping to get some help. After power is applied the word UNLOCK shows then PROTECT .Does anyone knows how to unlock, I would be grateful for your help. TIA. alimaj.

 

[Nelson Pass]

Does it do this with no speakers attached?

 

[alimaj]

Hi NELSON ,it occurs with the speakers disconnected, as well as connected. thanks . alimaj.

 

[AndrewT]

is this Sony using frequency and voltage detection to prevent grey imports?

 

[alimaj]

Hi Andrew I do not have a SM , I do not know if it uses that type of detection ( which I am not familiar with). Thanks. alimaj.

 

[alimaj]

Hi I have been able to get the amp .out of UNLOCK ,it is now in PROTECT.This amp. is similar to STR-DE 495P9 EUROPEAN MODEL).Is there anyone with experience with this problem, please share your experience. alimaj.