Re: Samsung smart tv bad power board BN44-0503A
Remove MOSFET QP801S, then:
Check all the components off the "gate" of QP801S, replace components as needed.
The PFC Control IC (ICP801S) may be shorted.
Check capacitors CP818 and 819 for short
Check diodes DP802, DP803, DP808 for short, and that they don't reverse bias.
Check Rectifier Diode BD801S on the DC side for shorts, for a good diode reading on all 4 terminals and that it does not reverse bias. When checking for a good diode reading expect the + and - diode reading to be about .9 instead of .4 to .6.
Let us know what you find.
I just repaired a BN44-00502A which is similar to yours
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Samsung smart tv bad power board BN44-0503A
Hello, got Samsung smart tv with bad power board BN44-00503A, diagnosed bad MOSFET F13NM60N (QP801S) and 5A fuse, after replacing both, replaced mosfet burned out immediately, fuse is ok, maybe somebody knows what can be checked prior trying one more?
Attached FilesLast edited by xfox; 06-14-2021, 10:40 PM. -
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Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
I hope this is the right forum to post in despite not technically being a repair, but still a question of swapping boards.
I thought I'd explore the possibility to upgrade an existing working Samsung ue55nu7096u with the logic board (and power board if needed) of a newer model (ue55ru7105k) of the same size and appearance (and resolution). The reason being I'd like the extra inputs of that board including component in, an extra HDMI port and bluetooth. Its panel is broken so I have no use for the board otherwise.
The models launched in 2018 and 2019 respectively.... -
Samsung LN46C630K1F – Intermittent Backlight, BN44-00341B Power Board
Summary for TL-DR readers:
• Backlight is intermittent, may come on with TV boot or not. No flickering, never fails during TV on.
• Have obtained Samsung schematic & service documents - Can upload if helpful.
• Have read ALL applicable threads
• C1818 and CP820 replaced as low hanging fruit
• CN802 data taken for normal and failed BL operation. SUMMARY: Pin 2 - 5vDet = 3.52 @normal, 0.0 @BL fail. Pin 6 - EPWM = 1.631 @normal, 1.058 @BL fail.
• VCC pin (18) of PFC... -
TLDNR; Have an old SAMSUNG TV with blown hybrid MOSFET/controller IC on power board to be replaced; replaced blown main capacitor on same power board several years ago successfully, and TV has been working fine since until this IC popped all of a sudden. Want to know what if anything to check on board to make sure before replacing and testing with new IC. Have 2 new matching ICs, DIP socket to make removal/replacement easier, a whole other known-good power board with which to compare, if necessary. -
Samsung UN65KU6290F (May 2017); received from local Buy Nothing group. Was listed as "just went dead" and they wanted it gone. I brought it home, didn't notice anything visually wrong with the power supply board, looked up the cost of a new one and that's about as far as it went. Family was tired of tripping on the foot of the set so I decided to dig in and repair or toss.
Can't believe that I didn't check it earlier but I found the main 8 amp fuse blown. Jumped across it with a 10 amp blade style fuse and you can see that it literally exploded inside the second I plugged...
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