Hi. Labeled SP803 on the board, translucent plasticky yellowish look, surface mount, full continuity.

It is in series with backlight LEDs driven supply in a TV at around 100V. The + path marked red.

 

Hi. Labeled SP803 on the board, translucent plasticky yellowish look, surface mount, full continuity.

It is in series with backlight LEDs driven supply in a TV at around 100V. The + path marked red.

View attachment 133068

Maybe a FUSE.

 

That was my first thought also, re-settable type?
Strange on the under side of the board?
Max.

 

LED?

 

What silk screening is nearby. Could be a ferrite bead.

 

Smells like a poly-fuse, but the color is not as tan-ish as US parts.

ak

 

This is weird. There is another on the same board, labeled SP801. Connected to nowhere. Just soldered on its pads with no vias nor anything on the top side.

Picture is horrible, same part 3mm x 3mm x 2mm at center. They are not tall enough to be "Standoff, Plastic" The board uses an insulating sheet under.

 

tits

 

This is weird. There is another on the same board, labeled SP801. Connected to nowhere. Just soldered on its pads with no vias nor anything on the top side.

Picture is horrible, same part 3mm x 3mm x 2mm at center. They are not tall enough to be "Standoff, Plastic" The board uses an insulating sheet under.

View attachment 133069

Inrush current limiter ?

 

The appearance is like a yellow diffuse cubical LED. Ferrite beads on the board are labeled BEP8XX. A fuse somewhere else on board is labeled FP801S

Looks like this with nothing visible inside, no leads :
----> http://www.tandyonline.co.uk/media/...d08d6e5fb8d27136e95/s/q/square-yellow-led.png

 

The appearance is like a yellow diffuse cubical LED. Ferrite beads on the board are labeled BEP8XX. A fuse somewhere else on board is labeled FP801S

Looks like this with nothing visible inside, no leads :
----> http://www.tandyonline.co.uk/media/...d08d6e5fb8d27136e95/s/q/square-yellow-led.png

Maybe Inrush current limiter for the backlight circuit or some kind of protection device for backlight circuit.

 

Pads/traces going nowhere, not much inrush to limit there. An almost decent picture, holding a loupe in front of the camera :

 

... full continuity...

By that you mean low ohms in both directions?

How about Shutdown Protection? Something that melts at a certain temperature. The unconnected one would indicate overheat to the PCB from off-board heat source.

Grabbing at straws, I admit.

 

I believe that they are indeed Standoffs, Plastic. The one with full continuity is because the trace underneath is connected to both pads (the part is placed on a trace). They may be there for compliance standards, to insure that the traces are kept at a minimum distance from other objects.

 

Pads/traces going nowhere, not much inrush to limit there. An almost decent picture, holding a loupe in front of the camera :

View attachment 133073

Multilayer PCB.

 

Giving up. Single sided board. This is the top side. Both mystery parts are bidirectional full continuity. The unconnected one is under "eyelet size" marking left of the third '100uF' brown large electrolytic.

Thank you for your patience, fellows.

 

Giving up. Single sided board. This is the top side. Both mystery parts are bidirectional full continuity. The unconnected one is under "eyelet size" marking left of the third '100uF' brown large electrolytic.

Thank you for your patience, fellows.

I see large Capacitor in SMPS circuit. Fuse, MOV, line chokes, Bridge rectifier diodes, SMPS transformer,. Is this only power supply board ?

I guess the Green component like MOV is NTC.

 

...Is this only power supply board ?...

Yes. It is a Samsung TV. White connector by bottom right supplies to LED backlights. Black connector by top right supplies 13V to main board and gets PWM (brightness?) and turn-on signals and whoknows what else.
Did not find a service manual to see the parts description/bill of materials.

 

Looks like a power factor corrected switcher, although with only 100 uF of bulk capacitance it isn't a very big one. But the layout is weird for that, and there is only one power device. Hmmm ...

ak

 

Looks like a power factor corrected switcher, although with only 100 uF of bulk capacitance it isn't a very big one. But the layout is weird for that, and there is only one power device. Hmmm ...

ak

Yes, the single mosfet must be for power factor correction circuit. It will be in series with the +ve rail.