Sunday, September 11, 2022

Quick Yard Sale Ryobi 40V 300W Power Source Repair


Picked up this Ryobi 40V 300W Power Source at a yard sale for a buck (they had it for $2 but it hadn't sold yet, so...) The seller said it did't work, that his son had fixed it but then it didn't work. Who knows. They sell for $119 at Home Depot so I have incentive to make it work. I have two 40V ryobi batteries for my lawnmower and blower.


Two screws. All screws except for the PCB screws are various Torx.


Two more screws hidden by the swinging handle.


Two more screws by the fan.


And I'm in.


Removing the fan screws.


Removed the bottom 4 screws and the bottom comes off.


Nothing looks bad. Two phillips screws retain the PCB.


There's a soldered in blade type 15A fuse on the other side. I couldn't read any continuity between the two terminals. I quickly bodged on a fuse holder.


And it's alive!


122.1VAC with no load looks good to me.



Bad fuse removed. You can see the link is blown. It's smaller in footprint than a standard automotive type fuse. Ryobi could have designed this better.


Soldered in an automotive type fuse after nibbling down the leads to fit.


Plenty of space for a standard fuse...they could have put in a socket, or even better a resettable circuit breaker.


Charged up a running laptop from 50% to 100%. I'll call this repair good and see about ordering a proper spare next time I get components in. Who knows why it blew, probably powering too big of a load for too long.