ElectronicNoobBlog

I was sitting on my computer chair doing programming, then suddenly i ended up on the floor…

after couple of second needed for my brain to reboot i realize that chair just break off…

here are couple of pictures…

Here are old pictures of fixing “dE” door error on Samsung WF0600NXW washing machine by replace door interlock . Here You can see closeups and part number, after replace and assembly in revers order – working perfect.

Today I decide to make firmware (ROM) update, after finishing and restarting Android i get information about “Invalid IMEI”.

When my heart start beating again i start looking out for solution then develop many attempts to address the problem.

RT4 is unpopular phone, so there virtually none information.

Lucky chipset inside phone is compatible with Xiaomi solution and that software i used.

1. open Your phone, and on back label You have IMEI numbers for two sim cards – write them down.
2. using windows computer install https://allmobitools.com/downloading-maui-meta-3g-4g-imei-repair-tool/
   
   
3. after install open application using administrator privilege
   on right side click “reconnect”  remove battery and unplug usb cable,  install battery, plug usb cable there should be beep of plugging in usb device, after while You should see something like this:
   
4. from drop down menu on the left select “IMEI DOWNLOAD” and in new window click button “IMEI UPLOAD FROM FLASH”
   They should appear two tabs SIM1 SIM2
   You need to enter Your IMEI form point 1
   last digit is checksum so don’t enter it, it will be calculated automatically, if it match then You are good to go and can click “Download to flash”

After successfully write, click disconnect and restart phone, it should work properly 🙂

I miss that old good times when You could just replace cells in battery to make it fully working again 🙁

Here are pictures of me testing Smart-UPS made by APC model APC 750 before replacement of batteries.

On oscilloscope i check true sine wave while working on battery (while testing on a power supply).

As You can see there is a beauty-full sine wave!

There are also visible connections in case You have that ups without battery.

Some random UPS APC simple repair job – no DC charging – failed capacitor, after replace working perfect.

They are very old photo and i don’t remember what king of model it was…