Win 8 Preloaded Laptop repaired for no media present error on booting

no media present in windows

Customer walked in to my workshop with Toshiba laptop stating the problem when he power on the Laptop instead of booting OS he is getting error on boot

››No Media Present……..

no media present

On inspection I found that this laptop is having win8 preloaded so first I have checked by pressing F8 on booting but it does not show any effect and giving same error as stated by the customer. That means the boot partition is corrupted because it is not giving the option of recovery. On doubt about this symptom I have to try it by recovery method using Bootable OS DVD.

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Mobile Phone Charger Cover Replaced

I am having one multi pin mobile charger adapter which is working fine since last two year but one day it was accidentally broken and its mains pins come out from the adapter’s body by damaging the surface very badly.

mobile charger adapter repair

So first I decide to take “two” pin power cord and attaché directly on the circuit in place of the pins. But again I have to manage that broken adaptor body part by sealing properly. I have started the work but just kept it on hold because if I do so again it will stuck on proper fitting on adaptor which is tedious job to arrange the corner broken side. Read More

Asus laptop power supply repaired. ADP-65VH B

how to repair power adapter




An old man brought his laptop and the power supply for repair. For some reason, the laptop was not powering on. It could be either the power supply or the laptop itself has problem. I tested the output voltage on the power supply and I got a reading of 22 volts. The output voltage should be 19. From experience, I knew the problem right away. The main problem was the power supply. Read More

Door Security Lock with Keypad

Hafiz Abdul Haseeb Tariq

Security is important everywhere. To secure things using the digits, keypads are used to take the input from the user. For this purpose, components that you need are:

Microcontroller: At89c51

Microcontroller At89c51

Keypad: cellular phone keypad (4×3)

Microcontroller At89c51 programming

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How to test KIA78R09PI

sir, May I know how to test “KIA78R09PI”. There is not output voltage
from the mentioned ic on the PCB of TV. and I can’t understand to
test it. please show some ideas to test it. hope lots of help comes.
thanks

 

Reply:

This is a 4 pins Voltage Regulator IC. It has an additional control pin and the signal usually coming from MCU IC to trigger the IC so that there will be output. If there is no signal to the control pin this means there will be no output. The first thing to check, the IC must have DC input first. You need to locate the datasheet in order find out the control pin. If there is an On signal (usually few volts) to the control pin and if the input dc voltage is presence and no output voltage then direct replace the IC. If the load has something shorted, it can also cause the output line voltage to drop. This also means you need to lift up the IC output pin and test. If still no output voltage then the IC indeed is faulty and need replacement

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