Sony MHC-W55 fm presets lost after unplug from wall socket

[deepaksetohul]

HELLO .. my Sony MHC-W55 fm presets are lost when the unit is unplug from power.. Thanks send help

[theHWcave]

I suppose the main unit (not the remote) has a battery. After all, it appears from a quick glance at the manual the clock keeps running even if the power is lost. That battery is  probably also used to store other settings. Sadly it is nowhere mentioned and it has probably finally died. You would need to open the thing up and look for it. If you are lucky its one of those CR2032 coin cells in a holder like PCs use for storing BIOS settings. It may be soldered in. I have seen that in a couple of motherboards and other electronic gear 

[SeanB]

Sony also used supercapacitors there, normally 0.22F 5.5V rated, you would find 2, one for the RTC and the other doing the presets. they do fail, or there is a CR2016 soldered to the board.

[deepaksetohul]

Thanks ... it indeed used a supercapacitor and in the MHC-W55 is the C501 thats needs to be changed