Xiaomi TV (MiTV) has a Black Screen

27 Oct 2018
# MiTV black screen,  faulty LED panel    
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This is a common complaint in MiTV and also in other makes.  Some of these black screen faults are caused by OS updates;  others are due to hardware component failures.  The Power Supply Board is usually the culprit.  This article intends to serve as a guide to troubleshoot this black screen problem, using MiTV4 as example.

How MiTV works?

MiTV has only a 3 components;  the Main Board (MB）,  the Power Supply Board （PSB）and the Logic Display Board (LDB) or commonly known as T-Con board.  The LDB  Board is usually shielded inside a metal cover.   Behind the plastic and metal covers,  there are also other components such as Bluetooth receiver,  the speaker modules and most important of all,  the LED backlights.   The following shows the layout and back panel of MiTV4;  other models of MiTV are quite similar

The MB  of MiTV4 contains the CPU,  I/O devices and the interfacing components to work with the LDB to light up the LED  panel.  The PSB will supply  12V  power lines to the MB which will do all the necessary startup and "instruct" the LDB, the indicators and the remote controls to work with the LED panel. The PSB also supplies the 96 Volt supply to power the LED backlights.

What can go wrong?

When there is black screen,  it will involve faults in the PSB,  MB and the also the LDB.  If these component boards are healthy,  then the fault could lie in the LED panel,  meaning the interfacing board within the LED panel might be faulty.  When this happen,  the repair will be complex.  Our 55" MiTV4 had a  LED panel fault and was replaced during the 1 year warranty period.

How to detect what went wrong?

The traditional wisdom is to shine a bright torch light as close as possible at the screen and at an angle  to determine if there are moving images on the screen.   In here,  the torch light is simulating the backlight to check if the faulty backlight is the cause.

The following suggestions should help to troubleshoot the faults.

Description	Possible causes and actions	Remark (Dbclick to enlarge video/pictures)
I)  No Moving Image and No Sound
1.  Power Indicating lights not on	1)  Make sure the power is plugged in and the remote control’s battery is good by replacing the battery 2)  If still not working,  press the white start button underneath and at the centre of the TV	Reference video found in YouTube for information (Click here for full screen)
2.  Indicating lights are on	Try to factory reset the OS by pressing the [Confirm] and the [Restore] at the same time and start the TV by pressing the white start button after powering off  the  TV for about 20 seconds	(Click here for more information on how to do a factory reset).
3)  The screen is still in complete darkness	If the TV has been synchronized before for screen mirroring,  use the hand phone to check if it can locate  the address to the TV	If cannot locate the address of the TV,   most likely the TV is dead with faulty MB or PSB
4)  The screen is back		This screen will be shown on successful factory reset.
II)  Got Moving images and got sound
	Suspect PSB has problem supplying power for the backlights Most likely the LED backlights are faulty.	Reference video found in YouTube for information (Click here for full screen)
III)  No moving images but got sound
	Check the supply voltages to the LDB and PSB.   Most likely a)  The LDB is faulty or the LCD screen is faulty b)  The PSB is faulty

Flow Chart for the Repair

(Double click flow chart for full screen)

Why the Power Supply Board  (PSB) can be Faulty?

The Power Supply Board  supplies not only power to the MB but also the power to the LED backlight directly.  When instructed by the MB,  a high voltage (96 volts for 55" MiTV4) will be sent to the  LED backlight to light up the screen.  If there is a faulty LED,  this 96 Volt power rail will be short circuited  and this may damage the PSB.  The LED strip's  PCB rail could be  burnt off,  resulting power  not being supplied to a strip of  LEDs as shown in the following picture.

How To Repair the LED Backlights?

There is no repair video yet for repairing the backlight of MiTV4 series.  In particular,  the MiTV4 has a 9 mm thick LED panel,  requiring Edge LED or ELED type of  backlights  to be installed at the bottom of the LED screen instead of installing it directly behind and underneath the LED panel (Direct LED or DLED)..  Because of this,  many users of MiTV have complained about the heat generated by the backlights at the bottom of TV.   

However,  here is good video about how to replace and test the LED backlights for common and traditional type of  TVs with DLED.  This could apply to other MiTV4 series such as MiTV4A etc

Usually,  users were able to repair most TV problems by first replacing the power supply board,  then follow by the Main board or logic display board in that sequence.  

How to Prolong the life of LED backlights?

Users have been advised to lower the brightness of the TV to about 50%  to 75% so as to reduce the heat caused by the LEDs backlights.   Having proper ventilation at the location where LED backlight is located will prolong its life. 

Where can we buy the MiTV Spares?

MiTV spares are often offered for sale in TaoBao as the vendors stripped old broken TV set to salvage the parts.  They would usually test the boards and give 90 days warranty or money back if the board can be returned within 7 days.   However,  it is always good to ensure that one would not be cheated when buying stuff from TaoBao. 
If one cannot find the spares in TaoBao,  it may be because the MiTV is quite new and one might have to wait for a while.

The Boards of 55" MiTV4

The following pictures are taken from a 55" MiTV4 .  When ordering the part,  give the vendors the correct  parts number copied directly from your TV.  

The Main Board	The Power Supply Board	The Logic Display Board (Different for different panel makers)
The remote Control Board	LED strips w/o alum panel	LED strips inside alum panel
Speakers and Remote control

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Don’t Throw Away That Old PCs (Part 1)

26 Oct 2018

Note:  This Part 1 is for PCs that have Intel Rapid Storage Technology.  Part 2 for other PC  can be found here in this link

It can be salvaged for your kids to play computer games.

The kids’ games have become more sophisticated nowadays.  They used to be a few megabytes in size, then they grew to a few Gigabytes.  Nowadays, the games,  such as FiFa 19, are in the size of 50 Gigabytes and they demand faster disk drives and graphic cards too.

Why the Old PCs?

These old PCs such as those with Intel® Z68, Z87, Q87, H87, Z77, Q77 or H77 chipset has usually a small built in for SSD MSATA drive.  This little MSATA drive can be used as cache SSD drive to speed up the mechanical Hard Disk Drive (HDD) by about 2 to 3 times using Intel Smart Response Technology (ISRT) . 

Why Not use SSD Drive?

SSDs are still not cost effective.  The 1TB SSD will cost around  SGD$400/= whereas 1TB HDD cost less than SGD$60/=.   Moreover,  these SSDs consume more power than the MSATA SSD cache drives as HDD will not always be running full time and HDD  may be set to rest in the IRST mode . 

The Setup

This  old Z77 Gigabyte motherboard  being upgraded has an Intel I5 3570 CPU.  The board has already a 32G MSATA SSD installed.  The purpose of this article is to help those who wanted to install SSD cache drive to speed up the mechanical HDD. 

What is Pre-requisite?

1. The Motherboard must have 

a) Chipset  that supports Intel Smart Response Technology (ISRT) 

b) SATA controller that can be set to Raid mode (no arrays will be configured)

Older motherboard manufactured earlier like ASUS P5K would not be able to support ISRT.  

2. The PC or Laptop must have a SSD drive and a hard disk drive (HDD)

3. The software required are

a)  Intel Rapid Start Technology (IRST)

b)  The F6  IRST drivers for the window OS

What is IRST and ISRT?

It is a technology invented by Intel to speed up HDD when SSD was expensive.  ISRT is one of the features in Intel Rapid Storage Technology (IRST) that help users to store frequently used applications temporarily in SSD so as to improve the overall performance of the HDD. 

What are the other Requirements?

1. The SATA controller of the motherboard must be first set to RAID mode (no arrays need to be configured)

2. The Intel RST software can be installed after the OS has been installed.

Assumptions 

1. OS is Windows 7 though same could be applied to other OS 

2. SATA mode in existing BIOS is [AHCI] or [IDE];

3. Gigabyte Motherboard has a cache SSD drive and a HDD

What about ISRT in Other PCs like ASUS?

One can use also other brands of PCs that do not have in-built  slot for MSATA SSD drives provided they meet the pre-requisite requirement.  One can use another smaller SSD drive but the set up may be slightly different from those described here.

Is Re-installing the Windows OS A Must?

The recommended practice  is to start afresh by re-installing Windows OS as there are some modification to be made to the Windows OS.  However,  for newer Windows installations, especially Windows 7,  these standard modifications have already been added.    ISRT has been successfully installed in existing Windows 7 that have SATA disk formatted in  AHCI.

Important Note:-

1. Step 1 and 2 is a must;  otherwise,  there would be installation problem such as not able to find the hard disks.

Step by Step

Description	Action	Remark (Dbclcik to Enlarge Pictures)
1.  Set motherboard in RAID mode	Hit [Del] button at the start to get into the setup screen.  Navigate to [Peripheral]’s [SATA Mode Selection] and change the setting to [Raid],  leaving the rest setting and [Save and Exit] the setting.
2. Fire up the PC and one would be greeted by this screen showing the various drives after hitting [CTL-I] in the startup screen	Do nothing.  Just to  make sure the drive are all in [Non RAID] Disk.  Reset the drive mode to [Non RAID] if necessary	In this case,  there are 2 drive;  one 1TB HDD and 1 32GB LITEONIT SSD MSATA drive; Take particular note that the drives are shown as [Non RAID Disk].   If it is in other form such as [cache Disk] or otherwise,  change them to [Non RAID Disk] using [Reset Disk to Non RAID] option.
3  Prepare the F6 drivers	Download the F6 drivers and put them in a USB thumb drive	F6 drivers will be necessary when the drives and OS  does not comply to these requirement Download the F6 driver from here
4. Download IRST software	Download the IRST software from Intel Download Centre	Some newer versions of IRST might not work for older version of Windows OS such as Window 7.   Try downloading version 15.2.16.1060 or other version if necessary
5. Windows 7 OS Installation	1. DO Nothing if your existing SATA disk was formatted in  AHCI; Goto Step 4 2. Otherwise,  proceed to install the OS.	Important:  All data in the HDD will be wiped.    If one has set drive to [Non RAID],  one should see the drives in this picture;  otherwise, follow step 2. It is also time to install the F6 drivers prepared in step 3 by selecting [Load Driver]
6.  After Windows OS installation	Check that the F6 drivers have been installed by running [regedit]  as [run as Administrator] .  Navigate to [IaStorA] folder as shown.  If the [Start] is not set to (0),  change it to (0) as shown	Note:  [start] = 3 is AHCI mode and [start] =0 is RAID mode
7.  Install or update chipset drivers	Download the chipset drivers either from the motherboard’s website or from Intel website	Try using Intel’s driver and support assistance to check if there is a need to update the drivers
8. Setting up RAID cache in SSD	Fire up the ISRT software downloaded in step 4 Now press [Enable] as circled red to create the RAID cache drive	Take note that the drives should show up with HDD as system drive and SSD as ordinary drive.  Once [Enable] is pressed, the SSD will change to show as  RAID cache SSD drive
9  Accelerating HDD	Select [Performance] tab and in the [Acceleration Configuration] select enable	The screen will change to following Now we are ready to re-start the PC
10 Complete with a re-start	Re-start the PC	When this screen shown in Step 2 appears again,  notice that there is a green asterisk marked against the HDD indicating it has been accelerated. The PC will start in normal mode to re-configure set up to speed up HDD.   Re-start the PC  if prompted.

Results

HDD w/o IRST	HDD After IRST

 Common  Problems

Description	Action	Remarks
1.  Cannot find hard drives  when installing the OS or using Diskpart	Reset the disk drives as shown in Step 2.	If the disk drives are not correctly set,  the OS installer will not be able to find them.
2.  Cannot accelerate the HDD .. error code 0xA004 or 0xA005	Download older version of ISRT software and retry	The newer ISRT software is not compatible for use in older Windows
3. Cannot install ISRT software	Delete this key in [regedit]. HKEY_CLASSES_ROOT\Installer\products\	Some older version of software are in the way.

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Buying From TaoBao or TMall; Avoid being Cheated

23 October 2018

The Taobao’s stuff are cheap;  cheaper than AliExpress.  But one would have to manage the expectation especially for overseas residents.  Dishonest sellers will not only sell us imitated goods but also sell us broken or damaged goods.   This article intends to provide some information about  how to avoid being cheated.

How Do they Do it?

One common trick the dishonest sellers might  do when they know you are an overseas buyer is to sell damaged goods which are rejected or returned by the local residents.   The other ways they might do is to pretend that they never heard you properly and sell you out of date products or keep the free gifts for themselves.    They would appear to be very helpful promising everything under the sun and pretended to comply to your instructions which they might never honor.  

When the goods finally arrived,  you might find out that it not to the requirement,  they will tell you to return the goods for a refund,  fully knowing very well you would never do so because

1.  By the time you receive the goods,  the "7 days not question asked refunding period’  would have lapsed and insurance would have expired;

2.  The delivery fees for the return of goods will be so exorbitant high that they would never promise that you will get the delivery fees refunded.

They might engage with you the conversation about a resolution or refund  that you have proposed but they might never agree.   At the end,  they would insist that you return the goods to get the refund.

What could have been done to avoid?

1.  Never ever reveal where you are from

This is sometimes not possible because you will have to give them the local address of the container warehouse for the goods to be delivered.  The smarter and experienced ones will immediately spot you out;

2.   Check the reputation rating

This helps but not always because the rating of those nasty sellers can be surprisingly good;  some even have been rated above average;

3.   Check the reviews in their site

This again can be misleading although it is no harm checking through especially those remarks given by overseas buyers;   avoid those having little or no reviews.

4.  Check for complaints in public domain

This is by far the better way to judge the reputation of the shops in Taobao.  If there are complaints written on the shop;  avoid by all means

5.   Others

Some buyers recommended 

1   To check the advertising materials in the Webpages;   usually,  the good ones will not "pirate" the materials

2.  To check the accumulated reviews and orders of the goods sold.    Usually,  the goods ones will have a lot of orders and reviews;   look for those repeated orders

3.  To avoid buying during peak period or during cheap sale period.  Orders can be easily mis-handled or missed out;

4.  Good things are not cheap and cheap things are not necessary good

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Fix Command Prompt (CMD) Open and Close Immediately

22 Oct 2018

Kids have been downloading games and their PCs were infected by a virus while installing a popular game.  It has the following symptoms

1.  The Command Prompt would open and close immediately and thereafter;

2.   The Windows will not start to show the usual Explorer windows but a Command Prompt window

 Step by Step

Description	Action	Remark (Double Click Video/Pic to enlarge)
1.  Fix CMD open and close immediately Symptom as shown in the video	1. Startup [regedit] and [Run as Administrator] in the Search box after pressing [Start] button 2. In the regedit window, navigate to  [HKEY_CURRENTUSER/Software/Microsoft/Command Processor] ,  one would find the [Autorun] key. 3. Right click mouse at [Autorun] and select to  delete the whole key.
2.  Fix Window Won’t open up Explorer at startup	a)  If only a [Command Prompt] is always shown;  otherwise,  goto step b) At the [Command Prompt],  key-in [Explorer],  the familiar Explorer screen would appear.  Alternatively,  One can type [Regedit] at the [Command Prompt],  the registry screen will show up. b) Following Action 1 above to open regedit window and in the regedit window,  navigate to [HKEY_CURRENTUSER/Software/Microsoft/Windows NT/CurrentVersion/Winlogon],  one would find the [Shell] key.  The key should only contain [explorer.exe]

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