yes i agree with brewski
24v reading means they are not charged, might be why the battery lights are flashing.
The manual says to check the AC main power supply, which we know is working because it turns on, also says to check the DC fuse may be blown, and lastly it says the power circuit break down.
It does have a protection mode that if the DC fuse blows it will cause the red led to blink so check that fuse and it's connections.
when you start the charger it should try and charge for 5 mins, if the DC circuit is faulty (ie: blown fuse) it will start blinking.
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