Works on Mains not battery

Check the battery it may have a high internal impedance.

sounds like to me you have a bad connection in the battery terminals. try cleaning the contacts with a Emery stick.

Seems the battery has gone bad prematurely. Charging circuits have to be good since the unit works fine off the adapter plugged into the mains.

I have noticed exactly the same issue with my Sony XDR-S55DAB

Even if it has batteries installed but only working off mains electricity, after several months it will not start when the power button is pressed and I have to replace the batteries.

The radio will work again if you just replace the batteries with fresh ones

Try this next time the batteries go flat; disconnect the radio from the mains, replace the batteries with fresh ones, and leave for a couple of minutes (you do not have to switch on!).

You can remove the batteries if you like then reconnect the mains cable and press ON

If your radio behaves exactly the same as mine, it will spring into life so how come?

In the "olden days" ie pre-2000, small portable radios often had a physical switch which connected and disconnected the power supply be it battery or mains.

Nowadays, many radios don't have a "proper" switch, but a "function" button - press it on, and the radio operates, press it again and the radio stops - to enable this, a very small amount of charge is required to keep the central "brain" alive in order to notice this, and in the case of the Sony XDR-S55DAB, this only seems to be supplied by the battery, not the mains adapter.

My advice is simply keep a spare set of batteries handy and replace them whenever your radio wont turn on. Using the mains adapter allows the batteries to lastfar longer than using the batteries on their own.

It is completely counter-intuitive that a "battery/mains" radio needs batteries to work off the mains, but this is the only design fault can find in an otherwise excellent radio.

Change the battery in it. It can be found online. It is easily accessed on the back of the radio, by unscrewing 2 philips screws. I had the same problem with mine, with an old battery. Once turned on, I could unplug it and it would play for 12-14 hours. Apparently the iPal needs a higher voltage when it turns on, so your old battery is not able to deliver that.

I take it the battery has life in it ? check the connections to where the battery makes contact on the radio, your battery contacts may not be connecting to the radio or they may need cleaning. Does the radio charge the battery still ?

Yeah the same has happened to lenovo x61s, i contacted the supplier and they told me i need a new battery, unfortunatly laptop atterys arnt the cheapest things around

replaced the circuit board where it meets the battery

Theres an internal error you will need to get it sent off for repair

send your radio for repair. till the guys at the service for grc repair cost. very economical rather than you do it your self if you are not sure of the problem. radio need 3 circuit borad or also a charger