Re: Samsung PS50C550 Voltage Drop Help



Yes correct swapping with a new power board did not correct the problem?...

Re: Samsung PS50C550 Voltage Drop Help



Yes thanks for your response. I have swapped out all the boards but not the main. I didn't believe the main to be the problem as the voltages only drop when the LVDA cable from the logic is connected to the Y sustain.

This happens when no ribbon connectors are connected to the main....

Re: Samsung PS50C550 Voltage Drop Help

Hi Bill,

Still puzzled. Seems I wasted some more of my hard earned cash on a power board which did not rectify the problem.

To Recap I have a pal system where VS and Va are generated on the supply board. Vscan and Ve appear to be generated on the Y and X respectively however these are not connected to the power board.

I have attached a simple flow chart of what I have and hope it helps.

Basically the tv powers on with VS and Va correct (High) when the LVDS cable is not connected...

Re: Samsung PS50C550 Voltage Drop Help

Thanks again. I though it would be an easy swap. Wasn't aware it needed special Samsung coding. Will have to save my pennies for a new Power Board then.

Re: Samsung PS50C550 Voltage Drop Help

Cheers PlainBill for you reply. Sorry I was not so clear this is my first post. I will try and make it a bit clearer. My suppy board is numbered BN44-00330B Scematic attached. On this board there are three connector termanals. None Supply Vscan or Ve so I presume they are generated on the Y board and Z Board respectively.

Connector CN804 feeds the y board and the Y board appears to feed the Z board so disconnecting this cable I disconnect power to both Y and Z boards.

Connector Cn801 connects to the Main board...

Re: Samsung PS50C550 Voltage Drop Help

Can someone please help me with this?

Hi there I have been looking on line for a while now and cant seem to find a similar instance of my problem. I have a black screen with sound. on power up the LED flashes 3 times and stays on at the 3rd flash. I have tested voltages VS and VA from the main supply with only the main board connected and all is good. Connect logic board ok supply cable Ok. VS_on high 3.3V.

When ever I connect the ribbon cable from the logic board to the Y sustain board Vs_on goes low and i loose all me voltages. This happens also when there is no supply to the Y Board i.e. power cable to y disconnected....