Missing Component I.D. Needed

[Sam I Am]

Hello All,
I have a Samsung LN32A330J1N set that I recently acquired. The original owner stated the set "just up and quit without warning" as well as "nothing had been done to the set".
Got it home, pulled the back off, and lo and behold, two components (QM801 & FM801) had magically desoldered themselves from the power board; of which one (FM801) was totally missing.
It's the missing component that I hope someone on this forum can help me out with as I have been unsuccessful in locating a component parts list for this set.
In addition, I am at a loss as to what the designation of the missing component means. See the below pics for further evaluation.
Any and all assistance will be greatly appreciated.

[bluto]

Re: Missing Component I.D. Needed

F stands for fuse maybe?

[Sam I Am]

Re: Missing Component I.D. Needed

Whatever it was, it was siliconed to the aluminum heatsink as well as the diode to the left of it.

[PlainBill]

Re: Missing Component I.D. Needed

F stands for fuse maybe?

Possibly a fusible resistor?

PlainBill

[Sam I Am]

Re: Missing Component I.D. Needed

I think you may have nailed it PlainBill.
Now all I need is a spec and that will put me one step closer to possibly fixing this unit.

[PlainBill]

Re: Missing Component I.D. Needed

I think you may have nailed it PlainBill.
Now all I need is a spec and that will put me one step closer to possibly fixing this unit.

Couldn't you contact the guy who sold it to you and explain the folly of his ways? Perhaps an exchange could be negotiated; in exchange for him coughing up the missing part, you won't apply a golf club to his cranium.

Another approach would be to estimate the current flow and the power dissipation and use Ohms law to approximate the resistance.

PlainBill

[Sam I Am]

Re: Missing Component I.D. Needed

That was the first thing I did when I opened it up..... got the typical response though; deny, deny, deny. Yea, I'd like to really contact him alright... the schmuck.
I figured someone on this forum might know which service manual this set would fall under, or possibly have one of these boards lying around and put an eyeball on it, or etc., etc. (the possibilities are endless)
I'm pretty sure there will be multiple component failures other than this missing component (fusible resistor?) but I have to start somewhere.

[Toasty]

Re: Missing Component I.D. Needed

Take the picture with light shining so as to not have what you are looking for in shadow. The elderly have difficulty seeing, even with bionic implants...

It is most likely a fuse. The wrapping in a board picture I found on the web suggests a fuse. There is writing on the board right next to this item's space. Looks like ???? / 250v. Report that info back here, please.

Look up the board part number on the web: BN44-00235B

Check the images at shopjimmy.com: http://www.shopjimmy.com/samsung-bn4...wer-supply.htm

Keep in mind that a replacement, warrantied board can be upwards of ~$100.

Good hunting!
Toast

[Sam I Am]

Re: Missing Component I.D. Needed

I'll keep that in mind next time concerning the pic shadows. Heck, I thought most of you electronic guru's had X-ray vision anyway.
T2.0AH/ 250V is the writing next to the space and thanks for the link as this board, @ $70 shipped, appears to be fairly reasonably priced.

[PlainBill]

Re: Missing Component I.D. Needed

I'll keep that in mind next time concerning the pic shadows. Heck, I thought most of you electronic guru's had X-ray vision anyway.
T2.0AH/ 250V is the writing next to the space and thanks for the link as this board, @ $70 shipped, appears to be fairly reasonably priced.

That would be a 2A slo-blo, 250 volt fuse in a pigtail package.

PlainBill

[Sam I Am]

Re: Missing Component I.D. Needed

Thanks PlainBill,
I'll see if I can't dig one up around these parts and get this board put back together for further troubleshooting.

[Toasty]

Re: Missing Component I.D. Needed

Fuse blown, most probable suspect (for starters) is the other device that was unsoldered. QM801 appears to drive the nearby transformer, and the fuse is inline with the other leg of the transformer.

QM801 maybe shorted, and you'll need to test for that. Please report the markings on QM801 line by line or provide a clear picture. Also note that its' mounting screw is missing.

Safety - Everything inside the black line is HOT with respect to the wall outlet. Shock hazard if you put yourself across ground and *any* exposed metal, wiring, and circuitry inside that area.

Toast

[Sam I Am]

Re: Missing Component I.D. Needed

QM801 is a 800V N-Channel Mosfet I.D.#FQPF6N80C made by Fairchild. Also, I have the screw as QM801 was barely attached to the heatsink when the set arrived.

[Wizard]

Re: Missing Component I.D. Needed

This board has a samsung bulletin for defective diode. Ohm three big diodes, one of then is leaky or shorted around that yellow transformer, those are the three fat axial diode standing off the board. Replace the leaky or shorted one, I have done 2 while ago.

Cheers, Wizard

[Sam I Am]

Re: Missing Component I.D. Needed

Thanks for the info Wizard.
All 8 diodes on this board have passed an ohms check.

[Sam I Am]

Re: Missing Component I.D. Needed

Oops... make that all 9 diodes passed.

[Toasty]

Re: Missing Component I.D. Needed

See the MOSFET testing procedure:

https://www.badcaps.net/forum/showpost.php?p=79683

Must be out of circuit.

If needed, DigiKey has them for $1.40
http://search.digikey.com/scripts/Dk...e=FQPF6N80C-ND

Diodes checked with "Diode check" function or regular ohmmeter scale?

DMM or Analog?

Toast

[Sam I Am]

Re: Missing Component I.D. Needed

Mosfet is shorted and have ordered one (well two really, gotta have an extra you know) through Digikey as well as some pigtail fuses.
Diodes checked via the "diode check" function with a DMM.

[Toasty]

Re: Missing Component I.D. Needed

Okay. ID and check those devices on the output side of the transformer on the heatsinks and the 2 mounted on the bottom side near those caps. Can you post a clearer pic of that underside. It's -very- fuzzy. I cant tell if there are any other items for you to test under there.

What brand & series caps are those? The brown wrapper looks like UCC. No name spelled out, just the little shield emblem. Like the mains cap.

Toast

[Sam I Am]

Re: Missing Component I.D. Needed

If I am understanding you correctly, you want me to I.D./test the two components on the heatsinks by the cluster of caps.
The component closest to the caps (DM804) on the heatsink has the following info: CT 8225 below this is MBRF10150CT.
The sink beside it (DM807) shows PEC 830 below this is SB1060FCT.
I am unsure how to check these components.
Interestingly enough, the caps are series KY (with the exception of one other, excluding the mains) whereas the exception is series KMG.
Attached is a somewhat clearer pic for your perusal.