Author Topic: Toshiba 40inch with no screen.  (Read 211 times)

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vald

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Toshiba 40inch with no screen.
« on: March 30, 2018,02:45:52 »
Good Day,

I have a 40 inch (40E220U) LCD tv set that my neighbor gave me to repair with no screen lit. I first checked the power supply and only got 5v readings from the pin out. the 12v and 24v pins read zero. I then jumped the 5v pin with the power on pin and got the 24v and 12v. The voltage across the main filter capacitor jumped to about 340v. Is this normal?
When only the 5v is present the filter cap reads about 168v. If i jump the power on with the 5v the filter cap then increases to about 340v.
Also when the power on is jumped and the 24v is present at the inverter board i do not see the lcds come on. No screen. Is this normal?

Please Advise

Vald


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Toshiba 40inch with no screen.
« on: March 30, 2018,02:45:52 »

downunder

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Re: Toshiba 40inch with no screen.
« Reply #1 on: March 30, 2018,16:19:51 »

All perfectly normal, vald. Would suggest you have a faulty main board which is not supplying the necessary voltage (about 2.5V) to the power-on pin to activate the power supply. It also supplies an "inverter-on" voltage to switch the backlights on.

Bruce

vald

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Re: Toshiba 40inch with no screen.
« Reply #2 on: April 01, 2018,00:37:17 »
Thank you Bruce

Very Appreciated

I will change the main board

Mulja tv repair portal

Re: Toshiba 40inch with no screen.
« Reply #2 on: April 01, 2018,00:37:17 »

 

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