BT Response power adapter (BR4 - West Wickham south side)

Our answerphone suddenly isn't working any more, so I think it's the mains power adapter which has probably failed. Just posting this on the off-chance that someone has one hanging around somewhere so I can at least check. According to the instruction manual, the code for the adapter is 045209, but now I actually look at the existing adapter it has 078332 on it, so your guess is as good as mine which is right1