Sanyo DP50747-00 50" Plasma with Samsung innards

[Howie]

Bought this unit to see if it could be repaired.

TV power led comes on with a clicking sound, stays about 3 seconds and shuts off with a clicking sound. Nothing on the screen happens during this cycle.

Knowing most issues are PS caps I took the back panel off and to my surprise none of the caps looked bad. I went ahead and replaced all the output caps, even the small ones, with no change.

I disconnected the Y & X boards and tried power with no change.
I disconnected everything except the main control board with no change.

I haven't checked the output voltages on the PS yet, but wanted to have an opinion.
Wouldn't this suggest a PS issue or main board issue if the other boards are disconnected yet no difference in problem?

[PlainBill]

Re: Sanyo DP50747-00 50" Plasma with Samsung innards

Yes. Some manufacturers label the voltages on the output connectors of the power supply. Have you verified those?

PlainBill

[Howie]

Re: Sanyo DP50747-00 50" Plasma with Samsung innards

I checked the fuses and the fuse at F8201 on the power supply was blown and continues to blow them when the power button is pressed. Google search brought up that this usually means a diode at the D8302 location will be shorted as well. It continued on that these were replaced, but the TV would still not come on and they suspected the "MR4030 Partial Resonance Power Supply IC Module Supporting Standby Mode Operation" at the U8301 location.

[Howie]

Re: Sanyo DP50747-00 50" Plasma with Samsung innards

OK, I checked that diode and it has a big hole in the top and is blown. Now I cant make out the part number that was on there. Anyone have a service manual? Anyone think that it would be the MR4030 IC voltage regulator that was at fault and started the chain reaction?

[tom66]

Re: Sanyo DP50747-00 50" Plasma with Samsung innards

OK, I checked that diode and it has a big hole in the top and is blown. Now I cant make out the part number that was on there. Anyone have a service manual? Anyone think that it would be the MR4030 IC voltage regulator that was at fault and started the chain reaction?

What does the diode look like? It may be possible to replace it with any suitable diode based on where it sits in the power supply.

[Howie]

Re: Sanyo DP50747-00 50" Plasma with Samsung innards

From what I can research online its a UF4007 Diode Circuit Protector

They are two diode's right behind the small blue cap in the area I put a square around & the arrow is pointing at.

[SegueTx]

Re: Sanyo DP50747-00 50" Plasma with Samsung innards

I'm having the same problems with a Sanyo (Samsung guts) PS-50 W3-STD (assuming same power pcb is being used as in the DP50747). First the F8201 pops, and I'm noting that U8301 (B0883/MR4030 Transistor) is blown, along with a partial trace on the back of the board. The trace repair is no problem, nor is replacing U8301, skills wise on my part. My biggest question is this: If I replace U8301, F8201, and repair the trace, "should" it work when done? (the diode mentioned by others seems fine). Or should I just spend the $C note and pickup a whole new power pcb? This Tv is 3yrs, 3mos old and was given to me on a "get it out of here and you can have it" basis, so anything I spend on parts is my only investment. I've been into electronics for over 30 years, 16+ as a digital systems specialist (color and black/white electrostatic imaging equipment), so the skills are there to do the work. Not having schematics at hand is my main handicap here. There's always that debate for me, replace a $3 component and take a chance, or just go ahead and toss a new assembly at it (at 3x + the cost). Any suggestions appreciated!

Chris in Central Texas

[hijodalgo]

Re: Sanyo DP50747-00 50" Plasma with Samsung innards

what's the board number??does it begins with BN44-****??let me know,because I have some schematics for power board from samsung..BN44-00159A,BN44-00161A,BN44-00162A,BN44-00183A,BN44-00193A,BN44-00194A,etc..

[Redion]

Re: Sanyo DP50747-00 50" Plasma with Samsung innards

I wonder if replacing MR4030 solved the problem?
I have exactly same PSU with exactly same problem!
Would be nice to know if OP got it working...

[Redion]

Re: Sanyo DP50747-00 50" Plasma with Samsung innards

Hi every one, so here is my conclusion:
Replacing MR4030 and the little diode that shorted out beside it did the trick.
TV powered ON and works without any problems!