Lnt5271fx/xaa

[fxdfireman]

I got a Samsung LNT5271FX/XAA from a friend. When i got it it was dead no power, on stand by light. I looked over the boards and in my newbie thinking figured that the power supply failed and took out the main board. I ordered and replaced the power supply and main board and it worked when i turned it on. I turned it off and when i tried to turn it on again it would not do anything. Now it is like before no standby light. It does have 5V going to the main so i don't think its the power supply but what else would cause the main to go again?

Thanks for any help!

[dick_barton]

Re: Lnt5271fx/xaa

Can you provide a list of the legends alongside the connector pins and what the voltages are?

[fxdfireman]

Re: Lnt5271fx/xaa

OK Will get them after work.

[fxdfireman]

Re: Lnt5271fx/xaa

Here are the voltages and pictures. thanks for taking a look. Sorry it took so long to get back.

1 - 0.039
2 - 0.039
3 - 5.191
4-12 - 0
13-16 - 0.039
17-18 - 0
19 - 0.370
20 - 0
21 -0.370
22 - 0.374
23-24 - 0

[budm]

Re: Lnt5271fx/xaa

It would be nice if you had put the pin names for each pin.
Right now the main board is not sending the PS-ON signal (Pin 1) to turn on the rest of the the power supplies.
Try disconnecting the cable between the main board and the FRC board (the board between the main board and the T-CON board) to see what happen.
May be your new board is bad too.

[fxdfireman]

Re: Lnt5271fx/xaa

It seemed to work initially. I am thinking that whatever caused the first board to be bad caused the second to fail also.

[dick_barton]

Re: Lnt5271fx/xaa

Disconnect the power supply from the main AV baord and connect a 1K resistor between pin1 (Power On/Off) to pin 3 (STB5.2V) and check that all the other supplies come up.