Re: Ua40f7500 samsung tv dark picture
yes, but before i noticed i had already desoldered it. sorry.
Now i will fix it & check again....
aashiknaik
Member
Last Activity: 10-20-2018, 03:13 AM
Joined: 09-26-2018
Location: VADODARA
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Re: Ua40f7500 samsung tv dark picture
marked what i assumed.
As per your post Gate voltages shall be supplied by RT6905 GD point i think first i should fix IC...Last edited by aashiknaik; 10-10-2018, 04:05 AM.Leave a comment:
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Re: Ua40f7500 samsung tv dark picture
As i searched for D5 in s-manuals it shows PNP & NPN Digital transistor.
The images attached but the IC is removed....Leave a comment:
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Re: Ua40f7500 samsung tv dark picture
I tried one more t con of same pcb but of different model and got 2 images up and down section.But it was not dark as found in original t con.That T CON is suitable for UA40F6400.A very small capacitor is there between S and opposite terminal of 6 pin MOSFET.
The other T CON WHICH is suitable for UA40F6400 Model is giving 12.5v @hvin.
I tried to use MOSFET of that T CON but found no voltage at Drain.so, i replaced with original one. With original one i again got 10.43V.
Original MOSFET - D5EV. & the...Leave a comment:
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Re: Ua40f7500 samsung tv dark picture
Dear sir,
yes, you are right. MOSFET output comes to 10.43V @ 22u coil shown in RT9605 diagram which you have sent.
I have removed IC RT6905 before i show these posts.But it seems that the problem is with MOSFET or surrounding circuit.
AT source S it shows 12.6 V but at D it shows 10.43V.
At G it does not show any voltage. there is 1 resistor & 1 capacitor in series It doesn't show any voltage at resistor or gate but at capacitor input 12.5 v available.
WHAT VOLTAGES WE shall get @ gate...Leave a comment:
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Re: Ua40f7500 samsung tv dark picture
Dear sir,
Thanks for the prompt reply,
Actually i didn't expect prompt replies from tech buddies but you all are really the most helping hands or let me say helping minds.Really appreciate all.
Meanwhile i had removed ic so, let me fix ic and then will study all voltages and then again come with all pics and details to you.
Thanks a lot again,
Aashiknaik...Leave a comment:
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Re: Ua40f7500 samsung tv dark picture
Thanks dear Davi.P,
I have removed IC.so, let me fix new ic and again i will go thro' and come to you.
But thanks a lot for the prompt reply.
Will post reply once i fix IC and find why HVIN is low....Leave a comment:
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Re: Ua40f7500 samsung tv dark picture
Thanks for your reply,
I had tried with brightness control and contrast setting.but not much difference.
Backlight setting unable to operate.Leave a comment:
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Re: Ua40f7500 samsung tv dark picture
I have received IC RT6905 GQW .
CAN anybody tell me that is there any difference between RT6905B & RT6905 ?
Hope somebody knows.Pl. give me feedback.
ThanksLeave a comment:
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Ua40f7500 samsung tv dark picture
Hi,
I m aashik naik from Vadodara,India.
I m facing problem of dark picture with my SAMSUNG UA40F7500 TV.
The T con board is BN41-01939B.
CN 98BN950 0963AL229 DS40892.
Backlight working.
Sound ok.
If room lights are off then can see the dark image and able to select source from menu,all commands visible but too dark.
Checked T-CON BOARD..
T-CON input voltage as well as IC input voltages are 12.5 v which is correct.
Here i have noticed less voltage at V ONE it is +10.2v i think it should be 27to 28v .
Other voltages... -
Re: New Members - please post your introductions here
Hello,
I m AASHIKNAIK & basically m mechanical engineer but have much more interest in electronics especially repairs and maintenance of electronic equipments.
I have seen that lot of technical people discuss their problems and resolve them with help of each other here and that's why i m here.
I have been repairing my own equipment and also friends' equipment
sometimes with the help of knowledge displayed on internet.Now, i can have guide from highly skilled people like you and it will...Leave a comment:
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