Life on FR4

My sister has broke her iPhone screen, and she hired me to repair as cheap as I can. I have bought a failed iPhone in second hand marker for about half the prize as new LCD module. Later, I tear it down and I had to realized, than it has a lot so called "liquid damage". This means somehow water get inside the phone and not properly cleaned it, or not even noticed. When water get inside some kind of electronic device and not immediately turned off and cleaned, corrosion developing and start eating the solder joints just like the rust in cars body. After I checked the screen connector, I noticed some damage on it too. I decided to replace these connectors so I desoldered from the broken one. Next I desoldered the connectors from the good one and luckily it is turned out that the problem is not as big as I first think. Only one pad needed a repair and I quicky ran a jumper wire on the display flex cable. It can be a good example for everyone, what the liquid does if get insid

Recently, I got a used Razer BLACKWIDOW Ultimate 2014 mechanical keyboard with the fancy Razer greenswitches inside. The keyboard looks awesome and I really like the illuminated keys too. I'm not a person who likes the lound, clicking sounds that this switches are make when you press them down but I decided to give it a try. Sadly, the smile in my face went away as soon as I plugged the keyboard in and started typing on it. Every second or third character was doubled or missed on the screen of my computer. Something was wrong for sure with the keys, this issue is called scattering by the way. Actually I know that before I bought the keyboard and this is why I was bought it. There was nothing left, time to investigate the source of this issue. After a few phillips head screws I got inside the keyboard, and I desoldered some of the failed switches. The switch itself was easily disassemblable, 2 securing on each side. The problem was obvious after I looked inside the switch, corrod

I really like my JBC soldering station, perfect and robous tool. I usually just put the handpiece back to its holder, and after a few minute the station will activate the hibernation mode (no heating). This is a great feature because you don't have to turn on and off the station, but sometimes, for example when your 2 years old daughter start exploring your lab this can be dangerous. If you let the iron in hibernation mode, it is start heating very quickly (5 sec. from room temp.) as soon as you pull the handpiece out of its holder. Fortunately, my daughter dropped down the handpiece in time, and she don't get burned, but this was a terrible mistake as a dad because things could be happen much worse than in my case. The problem is when the soldering station is turned on, you don't get enough visual notification about it. The display are saying "hibernation" of course, but if you tired or you are in hurry, you probably miss it, and you will forget to turn it off.

I get myself intro repairing Xbox One Controllers. I going to write some of my experience about repairing this thinks. Most common problem is the analog stick of course, moving part are the weakest point of any device. You can buy a replacement part for a few buck, but actually you need only the variable resistor part. You can clearly see what is going wrong here, the conductor layer are broked on the left green resistor. If you want cheap fix this stick you should only replace the faulty resistor. Disassembled analog stick Another common failure is the board-to-board connector.You can find 2 different pcb inside the controller which are connected by this way.The problem come up when the solder joints cracks.This is because the upper pcb get different kind of forces under in use. The solder joints give up and crack and can't conduct any more. Broken connector I attached more example here. Angry player XD And here is an interesting thing for the end: I tested out

I get another toy for this week.It is working great, exept it is not charging the batteries. Teardown time! Diagnosing the problem allways  starting with visual expection. You can clearly see what is wrong here Something blown up and burned hard The problem is clear, but how to replace a part that never existed in a good condition that is to say, you never seen it, just as a burned piece of silicon.Googling based on the PCB silkscreen get some hits but nothing usefull at all. I dig myself into the device power section, specialy in the charger circuits an I think this is some kind of regulator or protection circuit. Now time to thinking... How this tablets are made? Every manufacturer design his own pcb from scratch? Not of course.Semiconductors like RockChip are popular in this segment.Lot of manufacturer use these kinds of SoC and exist somethink called "solution".A full solution for tablets,smartphones,TVboxs and others. You don't need to searching too hard to

I love watching videos about reapiring electronics and common problems in this video are faulty ceramic capacitors.This little guys usually sit between Vcc line and ground used as a filter caps. This is great for smoothing voltage rails, but the problem comes up when this caps are failed and causing a dead short to ground. Your device will immediately turn off and never come up again. My Minix Neo X5 had a same problem when I bought it. After I opened up I see somethink strange, somebody tried to fix it by upgrading the fuse just like Tesla Motors did in they batteris . Probably he spend years to researching the right material for this job :D Shorted Fuse Detecting the problem was easy, same as in my previous post about A31s android tablet .Some measurement on diode mode and clear to see that we have a shorted a rail.You can find the WM8326G  datasheet online and usually this datasheet including a reference schematics.This is a good way to start discovering your device subsytem