SAFE MODE THEN BLANK DISPLAY?

A couple of weeks a go i started up the car and the radio flickered and went into safe mode, dont know what could have caused it, but anyway, annoying. However, since then ive just left it switched off and never bothered about it till now. Now when i turn on the radio it no longer displays anything at all and there is something coming through the speakers, but none of the buttons work so i cant do any tuning. The display is not broken as when the radio is off it shows time etc, when radio is turned on it just stays blank and remains non-responsive! Even though it no longer said safe, i tried the procedure to enter the code on the off chance, but it does not do anything at all. Radio is a Grundig Car 200, came with the car, an S reg Corsa breeze. Any ideas before i buy a cheap replacement to stop the girlfriend going completely mad and buying a new car when im not looking! Cheers!