Wednesday, January 17, 2018

Dead Xbox Powersupply Repaired

This powersupply of xbox was brought to me by my friend and it is to his younger brother and this powersupply is 110 volts from United States of America and brought here in the Philippines by his parents. The problem it was plug in 220 volts and became no power. When i open the case the varistor was blown and the fuse was open.

The fuse is rated 6.3 ampere and varistor rated at 240 volts. I checked other parts at primary section of powersupply and all is okay. Then i told to the owner to buy these parts at electronics store he cannot buy exact figure of fuse and instead he was given a glass fuse rated at 7 ampere and 230 volts varistor and i put solder it and after it was solder all parts substitute. I power it on and powersupply came back to life.


Another powerupply save from junk. Thanks hope you enjoy my simple repair.

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Tuesday, January 2, 2018

How to Read Varistor body number

varistor is an electronic component with an electrical resistance that varies with the applied voltage.[2] Also known as a voltage-dependent resistor (VDR), it has a nonlinear, non-ohmic current–voltage characteristic that is similar to that of a diode. In contrast to a diode however, it has the same characteristic for both directions of traversing current. At low voltage it has a high electrical resistance which decreases as the voltage is raised.

Varistors are used as control or compensation elements in circuits either to provide optimal operating conditions or to protect against excessive transient voltages. When used as protection devices, they shunt the current created by the excessive voltage away from sensitive components when triggered.(SOURCE WIKIPEDIA)


Here is the informations how you can understand the number written in the body of  varistorAliExpress.com Product - Free Shipping 30pcs, 14D471K 14 D 471 471KD14 470V 4500A.

 



And here is the link of the datasheet of varistor 



Monday, January 1, 2018

Electronic Massager No Power

This Battery powered electronic massager was no power. So I check the battery if it has charge and it is confirmed that it is in good condition . So I check the supply from positive supply of battery and it supplied 4.5 volts. But when you pressed the power switch it will not switched on. So I checked the power switch and it's not working. I replaced it with new one and the massager came back its display in its LCD display.

Devant Lcd Tv

This 32 inches lcd tv was brought to me by a man who buy junk things that can be used or resell or repaired again and he bring it to me and I buy it to him in a reasonable price.




 He said the screen glass i still okay and it has power, so i tested it and it has standby power but nothing can see in lcd because he said it has lights or the backlight itself is on.This tv include remote control.



So I pay him and I open the tv to see if its still repairable. When I open tv and inspect it I saw the powersupply board of the has darken some area and also the panel steel.


This means something happen in this tv that sparks. The first I do was to get my electronic contact cleaner made by WD4 and I spray the darkened part or the board of powersupply and clean it.Once the board has been cleaned I test some parts using digital multimeter

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 and found no defective parts so I proceed to plug it power source and push the power on on the tv and the tv show lights on screen glass or lcd but no display.


So the second thing I do is to check the voltages from the output of secondary portion of powersupply going mainboard and it show it has right and stable supply. I check the voltage on mainboard if it is good and confirm it is okay. Continue to check the voltage from  this mainboard that supply sourceboard that are attached the glass panel, some model or brand of lcd tv has t-con or timing control but this tv has none. So I first confirm if it has supply voltage. Mostly the supply of sourceboard or t-con from mainboard has different voltage like 5v 12v etc. But this tv has 12v supply from mainboard that has been delivered by lvds wire( low voltage differential signal) mostly you can check on red wire which is the supply line. So when i on my multimeter put it on dc range and I ground the negative probe and put the positive probe of tester on supply line of 12v confirm it has voltage  but when i follow it to the sourceboard and check if it has voltage on the smd fuse mostly it is white color or has a sign of F1on the other side it has no 12v so i wonder the fuse is open,

so i powered it off the tv and check the fuse on sourceboard if it is open and set my multimeter tester to ohm setting to confirm if it is open fuse and it is confirm open. I salvage a smd fuse on my junk board of lcd tv put it on and powered the tv and to my vision I saw a good display came a blue display with on scrren display no signal and now the tv is working perfectly.




 Another lcd tv junk has been revive and it can be used again for watching and entertainment. I hope you learned something in this article.

Sunday, December 31, 2017

Sony Crt tv vertical line

My aunt told me that her tv has a one line in the center. So I visited it and it was true that it has one line across the center horizontally and it means I should trouble in vertical section but sometimes it should not be case in other tv . But we should focus first on this Sony crt tv 21 iinch. When I open the tv I go directly to vertical section and check for loose connection and it has I am lucky that is minor trouble. By resoldering it the tv came back to life.


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Saturday, December 31, 2016

Satellite receiver ICLASS 9696XPVR HDMI repaired






The problem of this satellite receiver was could not boot up properly according to my experience the malfunctioning of power supply can make this problem since bad and not purified DC  if produced by power supply the very sensitive parts on mother board can not handle the bad voltages and their reaction is not working properly . After opening the cover  of this receiver every things looked good . except one of the electro caps in second stage of power supply with a very small curve on top I decided  to pull this cap out of circuit and test it.  on the body of cap was written 1000microfard @10v .  according to ESR standard tablet of  caps the ESR of this cap must be 0.1 but ATLAS ESR METER.


Read this 0.88 .and the capacitive value 600microfard the cap value was decreased 400 micofard so I decided to replace this cap with a new good one. After replacing the cap the machine booted completely when it truns on . after that also I reprogram this machine by updated program.

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Here  I have to say thank you to  my good friend MR ZED  for sending the up date program for this satellite receiver .
Enjoy repairing

By: Beh                     Dec 2016

Sunday, August 28, 2016

Samsung lcd tv with model number LA32R91B Is repaired

The problem of this tv was saturation of white color in picture. first I contact to sam service as customer  to ask any help For repair of this TV they asked me about model number and answered me that  these model numbers are not repair able and due to panel problem the best way to get ride of is salvage.  by experience I knew that this could be the problem of gray scale ic in the TIME CONTROL BOARD .this is 48 pin ic that more or less the size is little bite bigger than a lentis  AS15-G



Mean while a repair friend of main offered me a used TCON BOARD   in good condition with same specification but very expensive that is why I preferred to buy a new board .also i have to mention that I can not find the  ic in our local market and in case I find the ic replacing such small smd is a big challenge so I decided to order it to china suppliers and buy a new time control 
After one month receiving the board from china and replacing the 
board problem solved







This is only example of timing control board or T-con


image before repair


image after repalce a new tcon board



By: Beh of Iran