ElectronicNoobBlog

Here is simple example why it is important to do visual inspection on Your electronic applications.

In this case i was able to spot leaking capacitor before it failed and create more expensive failure.

Guess why it failed… maybe it’s because they use 35V and silk screen stated 50V?

Of course i will go for 50V… higher the better.

Another example why not trust in Chinese stuff 😉

I got myself a TRI PRC 152 replica radio because I like size of it and overall look of this dial band radio.

My budget was low and I had to chose between ruler antenna or H250 handset adapted by TRI company to fit their radio.

I chose antenna,  but meantime i got myself a original military H1089 handset, nice green almost meet TRI prc 152 radio and would make a nice couple.

From electronic point of view there are couple problems:

1. Impedance of microphone – it’s critical You can’t use without fixing it because You won’t be redable
2. Pinout problem – don’t disable built in TRI PRC 152 replica radio internal speaker when plugging in original handset

Overall look:

Solve microphone problem, it’s possible to build transistor amplifier for original microphone but I don’t see point, You can get from e-bay tiny microphones for less then 1 USD and fit it inside and that’s way i chose.

Replace microphone for modern civilian (HAM)  – You can get it from almost any modern hand-microphone.

I puncture plastic film to get almost whisper readability (indoor as base station) – if You are going to use outdoor don’t do this because You loose watertight and can be hard to read in lout environment.

Fixing always on speaker mic inside radio by shorting A-E pin inside plug.

If needed very lout sound – replace speaker inside handset for low impedance

Very simple fix of Fixing Imation Disc Stakka storage CD/DVD automated carousel.

It won’t eject disks. Cause was a damaged (loose) driving belt. There is not much force, so i replace it with a rubber band. Working perfect like new.

I got broken  CMIK MK-B60.

After investigation i found blown IC (amplifier) blown was in way that prevent from reading model IC, this is china equipment and no schematic was available. That is probably cheap generic amplifier IC  but i decide not to waste time and simple use off shelf amplifier IC in conjunction with DC-DC converter to provide stable power to amplifier IC.

working perfect everything including volume adjustment (it’s just attenuation of input for amplifier that have constant gain)  not looking great but cheap!,

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.