andycivil's video: Fix HP laser printer if crashed stuck on initializing or turns off for no reason

I'm going to show you how to fix your HP laserjet AIO printer if it shows symptoms like locking up (like this). Or turning itself off for no reason. Or getting stuck half way through initialization like this. Mine did all of these. Here's what I did to fix it. It requires an oven, and a soldering iron; it's a good idea to have a proper thermometer too. You need to remove the side cover. There's a screw on the back, and underneath there's a locking tab than needs to be pushed in. If you've got any protective covers on unused sockets get them out of there, they get in the way. The cover unhinges, then you have to tease it off straight once it's unhooked. Take note of the battery; you're going to have to unsolder it because the board is going to get baked in the oven. While you watch me undo all the connectors to this board, I'll explain that HP let their customers down a bit with a new more environmentally friendly soldering process. Unfortunately it led to a high incidence of bad solder joints, and the fix is to re-flow the whole board. Fortunately, this is something that a keen do-it-yourselfer can do at home. You need to set your oven to 350 Fahrenheit. To get an accurate temperature I put bricks in my oven and waited for the temperature to stabilise; it also gave me something solid to measure the temperature of with my non-contact thermometer. The bake time is 8 minutes with the main components on top. There are five screws to undo, and two little tabs that go into holes in the top corners of the board. You have to unsolder the battery, because it would pop in the oven. Remember which way round it goes! You're going to support the board on balls of alumin(i)um foil on each corner. (Yes, I started doing it upside down at first, I corrected it later.) I also covered over the rather soft looking plastic socket, out of fear that it would melt. I have no idea if this is necessary. So put your board on a baking sheet, component side up, minus the battery, and bake it for the required eight minutes. Remove it, and let it cool by itself for half an hour or so. Don't forget to re-solder the battery in place. Screw the board back into place, re-attach all the wires, and it should be fixed. I took this video yesterday planning to do the voiceover if it worked, so I can now assure you that it did work for me, and the printer is working correctly.