Another power supply unit defect!

Today, Mehrnoosh brought her PC to the company and asked me to take a look at it. She said, she can not turn her PC on anymore.

The first thing I did was plugging it to electricity and making sure its power cord is OK! Then opened  the case doors and detached power supply unit connectors from motherboard, HDD and ODD. Then tried to connect green wire to black wire via a jumper to make sure power button is not the problem. I realized power supply is not going to be turned on by connecting green wire to black ones. So, power supply is damaged (it’s possible that power button has problem too). We completely detached power supply and replaced it by a spare power supply. Everything was OK and operating system was booted. So, the only problem was the power supply itself. As, I know by experience, a lot of power supply makers use poor capacitors in their products, so they will blow up after a few years of working.

I opened the power supply ans saw I was right! Some of capacitors were blew up!

The main problem was related to a 10 volt/2200 micro Farad capacitor, so I suggested Mehrnoosh to replace it with a 16 volt or more, same capacity electrolytic (preferably, solid) capacitor or buy a reliable PSU like Cooler Master products. She chose the second option!

History of the United States (book)

I am not going to talk about project Gutenberg, but about a book I am reading these days. The book is History of the United States by Helen Pierson. Thanks to project Gutenberg, I can read books on my old Android phone. I did a  search books about people I always admire like, Benjamin Franklin, Abraham Lincoln and some other great people, but unfortunately there were not a lot of books about them. I can not hide my passion to the Unite States, So, I started reading EPUB version of the History of the United States in words of one syllable book on my phone.

There are several editions of this book, like 2010 paper back edition and the latest edition (up to the day I am writing this post!), but the edition I’m reading now is 1889 edition of the history of the United States.

Now, I’m reading page 33 and I really enjoyed reading these 33 pages. This is a thin book and I suggest you to read it.

My first serious coding with python3!

I made some free time to update my blog. I dedicate this post to my first serious code.

The situation:

Our company has a database of users who subscribed to at last one of our services and are MTNIrancell users. In the other side, MTNIrancell has a database of their users who are subscribed to one or more of our services.

The problem:

The problem was that MTNIrancell DB and our DB were out of sync.

MTNIrancell gave us their users list as a .csv file and asked us to compare the list with our DB and finally give the diff.


Abraham was struggling with our DB and MTNIrance’s csv file for a couple of days. Those days, I was reading Eric Matthes‘ Python Crash Course Files and Exceptions chapter. Abe asked me to help him. I was glad because I could develop a serious operational code.


Finally I developed this code using python3 and intellijIdea:

filename = 'ghosts.csv'

with open('irancell.csv') as mtn:
  mtn_lines = mtn.readlines()

with open('vada.csv') as vada:
  vada_lines =

line_number = 0

for line in vada_lines:
  line_number += 1
  print("Now reading line number: " + str(line_number) +" of vada.csv")
  if line not in mtn_lines:
    with open(filename, 'a') as file_diff:

The code was working and compare MTNIrancell’s csv with our csv file and exported the users exist in our DB which are not in MTNIrancell’s DB. The MTNIrancell’s DB had about 2 M records while our DB had about 1.1 M records.

My code was working but it was too slow. It compares those csv files about 5 records per second. Aberaham and Ali didn’t have enough free time to wait for the code to finish. So they googled and found comm tool. Comm could solve a problem in a very very short time rather than my Python3 code. It’s because my python3 code is a single thread/single process code while comm could use more thread/process. Although I am not sure I can use multi thread/multi processing to compare those files in a shorter time, but who knows, maybe I refactor the code someday to support multi process processing.

Disassemble Lenovo IdeaPad 300

Last day, Farshid asked me to take a look at Lenovo IdeaPad 300 that Mr. Ahmadi complaint he can not turn it on. Farshid spent some time on it and finally asked me for some help. I checked items Farshid has just thought may cause the problem. I thought it maybe something related to the software so we had to reboot it but as laptop was fully charged and waiting for depleting the battery might take a long time (because the device does not use battery. Finally as the battery is not removable in Ideapad 300, we decided to disassemble it! At this time Mehrnoosh joint us to see what is happening there. As I studied electronics and I had some prior experience on disassembling and mending devices, I started the work! Disassembling was somewhat easy. It got back to old days of hardware and electronic.


P.S. : The problem was something more serious, so we decided to sent it to one of Lenovo’s authorized repair shops.

What are the minimum features of a 2017 smartphone?

Before installing LineageOMS 14.1 on my Sony Xperia M phone, I decided to buy a new smartphone. In one side, I didn’t want to spend a lot of money for purchasing a high end smart phone. On the other side, I wanted to buy something had could be updatable for at least 2 years, so I can focus on other things rather than finding custom ROMs for updating the OS. Apple’s iPhones are very high quality smartphones, but they are very very expensive. I was thought about iPhone SE because its OS is iOS and it was not as expensive as iPhone 7 or even iPhone 6S. The only problem with iPhone SE was its front camera with 1.2 mega pixel camera. I continued googling but this time, looking for Android phones with minimum features I just like. Here are most important ones:

LED technology display

LCD era is over. Now, we are in LED displays. In a short sentence, LCD displays need a backlight and are not colorful. Colors are generated after passing light from red, green, blue filters. Read more about disadvantages of LCD. LEDs are naturally colorful (using different semi-conductors) and do not need any backlight. So they are brighter, use less energy and have vivid colors. AMOLEDs will be dominant display technology very soon. Sony, LG, HTC, Huawei and others awaited for Apple to introduce an iPhone with AMOLED display to follow its way and build their new display with AMOLED display.s


These days, mobile phone manufacturers try to use efficient ways of notifying people. From substituting traditional LED notification light to use second display like what LG V20 has. I think the most efficient way for notification is using AOD (Always On Display) like what Samsung is using on its flagship smartphones and even mid range phones like Galaxy A5 2017.

Finger print sensor

Take much time to unlock your smartphone? Do not want everybody to watch your password or pattern? Finger print sensor is a good way to achieve this.

Fast Charge

Our usage of smartphone is increasing. So better to buy a smartphone with fast charge feature.

USB type C

Everybody in this world have problem with attaching USB (Type A, B, MicroUSB and all other types except type C) cable and gadgets. It is not reversible and we almost attach 50% of times in reverse direction. It is an annoyable thing and in worst case, you may damage the port. Reversible USB Type C is the solution!

Good selfie camera

Go to trip and hard to find someone to take a good and sharp of you? You have to buy a smartphone with a good selfie camera. It’s better to have front flash, but it’s not a big deal.


At last but not least, price is an important item. You can use your smartphone maximum 3 years (if your phone is a flagship and 2 years if your phone is a mid level phone) if you want to update to the latest updates. So, I recommend you to not spend a lot of money for purchasing a very high end phone.

My suggestion

With this and that, in Aug 2017, my recommended mobile phones is Samsung Galaxy C5 pro. Its main features are 5.2″ display, Super AMOLED full HD display,  4GB of RAM, 64GB of internal storage, USB type C, AOD, fast charge, finger print sensor, 16 M pixel f 1.9 rear and front camera and Android Nougat with a price about 350 USD on Amazon.

If you can ignore using LED display,  Huawei Nova 2 plus can be an alternate.

The Circle (2017 film)

Last night, Forough and I watched the Circle movie featuring Emma Watson and Tom Hanks through a satellite channel. The movie addressed one of main concerns these days, “privacy“. Forough and I both enjoyed the movie and it made us to think about privacy specially in digital era more. I think Google, Facebook, Apple, Samsung and could become a Circle if they are more evil and more ambitious.

Take care of your privacy in your digital life!

Android Nougat on my 2013 mobile phone

Android 4.3 (also known as jelly bean) was the last official update brought to my Sony Xperia M (also known as nicki). My biggest problem with my phone was not its outdated OS, but lack of free internal storage space for installing new applications and lots of bloatware on my phone. My first try was to root my device and remove unwanted applications. Unfortunately, it didn’t go well because actually there were not lots of applications for uninstall.

I heard of custom ROMs specifically CyanogenMod and tried to install CM13 (Android 6.0 AKA Marshmallow) on my C2005 mobile phone. The first step was unlocking the boot loader. Fortunately, Sony provides a good support for unlocking its devices’ boot loader. This step was quite easy and straight forward. My phone was rooted and its boot loader was unlocked. So, I installed TWRP (Team Win Recovery Project) on my phone, and android tools on my Fedora desktop, and followed instructions for installing CM 13.  Everything went smoothly and after a couple hours, I had Marshmallow on my phone. After that, I tried to update my phone once a month or so.

CyanogenMod was faced a lot of problem and decided to stop the project and shuts down its servers. The latest version of CM I’d installed on my phone was the latest build of CM14.1 (Android 7.1.1) and had a few bugs that annoyed me a lot. The most nuisance I’ve ever faced with recent builds of CM was the problem that it was going slow and slow over time and I had to re-flash it again periodically. Even, I tried AOSP (Marshmallow and Nougat)  but I didn’t like it. It has fewer features and does not provide root access.

A buggy build of CM 14.1 on my Xperia M mobile phone

After CM’s shut down, I was completely disappointed of custom ROMs but as I recently disappointed of Samsung A5 2017 because of its front camera focus issue, I googled and find LineageOS for my nicki phone. The reason I didn’t try LineageOS in earlier time was because I read somewhere that LineageOS does not give you root access.

Now, I have the latest minor update of Android Nougat on my phone and I’m so happy with that. I also have flashed Open Google Apps and now, I am able to use all of features the official Google android ROMs have.

Special thanks to LineageOMS.

P.S. 1 : I didn’t faced any bug or problem during recent days after installing LineageOS 14.1 on my phone.

P.S. 2 : Actually as LineageOS has orphaned nicki support, so I tried LineageOMS!

Stable, great and lovely  LineageOMS on my Sony C2005 mobile phone

EleComp 2017

Two days ago, Ali, Mehrnoosh and me went to Elecomp 2017. Like previous years, mobile operators and ISPs invested a lot. I heard that it costs a lot for hardware manufacturers to participate in Elecomp exhibition. Also, I heard that next year elecomp and telecom will be merged in 1 exhibition with probably new name.

I am so happy to see few more hardware companies at EleComp 2017.

Here are few pictures of this year elecomp.

July 4th 2017

Well, I just know that today is Forth of July. But I do not know what to write on this blog post.

It’s couple months that I had some researches and few discussions about the United States. After all of those, I just figured it out that (almost) the strongest part of the United States that made it the United States of America is it’s constitution. Thing that is owed to Thomas Jefferson, John AdamsGeorge Washington, Benjamin Franklin, John Hancock and others. The latest thing I’ve read (actually I’ve listened because it was an audio book from LibriVox ) about the U.S. was A Short History of the United States  by Edward Channing .

God bless the United States and it’s constitution.