There's some very smart folks on youtube, diving deep into how these boards work. In some basic ways they all work the same but of course there's just enough variance in some to make it complicated at times.
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I will. Is there any chance it could be the FA6B22N?? I was saying that there was 7 volts on the FB line, but am not sure if that is normal or possibly is keeping the IC from fully operating...Comment
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I posted a pdf in post 20. Your VCC supply is underestimated 10v, but it should be about 18-22v​Attached FilesPremium supporters get full download access and other benefits.
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I wonder if CP810 is ok.Comment
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If you have not, check DP802 and 803 Diodes on underside of board by the big caps. Also double check all those resistors, make sure none are open or drifted.Comment
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Thank you all, I will check tomorrow.Comment
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With power applied on the bench, CM814 and CM815 have 10VDC, equal to the VCC of ICM801S, but CM810 reads 0VDC. Not sure what role it exactly plays, but there should be something right? Sure would love a schematic! 😬Attached FilesPremium supporters get full download access and other benefits.
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I would switch it out. Sometimes it's just easier, specially if you don't have an accurate cap tester.Comment
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Seems like we covered most of the potential faults, if it's not a bad solder, resistor, cap, guess that leaves the pfc IC. Guess you can check it for a short. I believe there's only one ground, maybe check, with tv unplugged, neg probe on neg leg of filter cap/hot ground, positive probe on each pin of IC, make sure only one pin has continuity as in only one will show 0 ohms or beep in continuity/diode mode if meter has that feature, same as testing a fuse.Comment
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Well, if this is a frequent malfunction, check the other components that are in the Repair list...Attached FilesPremium supporters get full download access and other benefits.
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Well test QP802CS, should prolly test the same as QP801CS, the numbers on them are the same, yes?Comment
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It would be easy enough to change out all the parts listed at the bottom of that parts kit. Those 4 blue caps and the 2 transistors, one of which you already changed out.Comment
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I'm at a loss....everything I've checked seems ok, but I'm having trouble following the circuit to understand exactly where the 10VDC (that should be 14-29) is sourced from. It appears to start tapped off that big transformer and through a diode, but how is the TXFMR producing V without any switching happening. Does anybody have a schematic close to BN44-00874F?? Can anybody confirm that this board should be fully on when on the bench (like other samsung power supply boards), or do I need to install it?Comment
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Did you replace CM810?Comment
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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.
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I did not have any 27uf @ 50 volt capacitors but one nice thing is that it has enough room for two capacitors in parallel a 22uf and a 4.7uf @ 50 volts 22 plus 4.7 equals 26.7uf which so very close to 27uf I will show some pictures of it sometime tomorrow
This is one of the shit est boards I seen in a very long time and it was the daughter board the traces just lifting off the board I had to use the capacitor leads to repair the the traces and the main board is not any better because I had to repair several traces for the daughter board to the main board
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I am attempting to test a samsung power supply board to verify the pfc ic is working. I am powering up the board with my isolation transformer. The board turns on fine but when I attempt to connect the ground for the scope probe, it trips out the isolator. I was taught not to 'float my scope' so I am wondering if I should test without connecting the ground lead or would that be asking for trouble? Not sure how else to test, I don't have a portable scope. I could plug direct to mains power but that would bypass the safety factor.
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I picked up this TV from Facebook Marketplace, original owner described it as "screen went black after a pop" and I hoped to see an obvious fuse or cap to replace. Doesn't seem to be the case, but my experience and electrical knowledge are kind of limited for this.
The power board (BN44-00445A, see attached) turns on and Vs and Va seem to momentarily have power, then they steadily drain to zero over a minute or two as if they're only getting power from capacitors. I've been measuring Vs and Va from the test pads, with and without the other boards connected to the power board... -
I was working on this CNC machine today found no keyboard functioning no control relay powering on
The screen powered on and was giving an operation error but the manual was not very clear about what the error exactly was but with a little bit of troubleshooting and finding out that the control relays not powering on and no keyboard functions we narrowed down to this one switching power supply which of course does not have any indicator LED light they are on the keyboard interface/relay controller board
Found shorted diodes on main controller relays there are 3 of them that...
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