LJB

Thank you, that's a very good bit of advice. Very logical and obvious when pointed out. Appreciate it

Keypad is mounted on brick face, whoever originally installed it has placed it over the mortor joints so water has been getting in through this joint. There is only 1 x 1amp glass fuse in the psu which is fine, I have removed the fuse also and done a test of it. As said, the keypad and maglock is now getting power and working as it should. It's just the red error light is now showing on the psu and is worrying me incase it's a fire hazzard. I have powered everything off for now. I have added a photo of back of keypad

Hi all I am not a security engineer just a home owner. I have a tool shed with a vanderbilt Act5e keypad controlling a maglock on the door. This is powered by an elmdene psu. It also has a green break glass and push to exit button. The power had stopped going to maglock and upon various checks with a multimeter the psu, break glass and push to exit switch was OK. I then removed keypad and water had made its way into back of unit and corroded the 12v and 0 terminals and the common wire had snapped. I have replaced the common wire into the 12v terminal and after connecting all back up, the red fault light is showing on the psu, however the maglock is now powered and working. I am thinking it might be recognising a short circuit due to the corrosion. Will cleaning the terminals correct this or will a new keypad be required or any other issues you think it may be. The psu also has a standby battery showing correct voltage. I am not an engineer, I really cannot afford an expensive fix as it's only a shed. I would like to try all things possible to me before removing. Thanks for any help or advice.