Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

[TVRepairNoobie]

Hi Guys,
I need help with this Polaroid FLM-2632. There are tons of Polaroid with this issue. But, I have not been able to find a solution online that will resolve this TV issue.

The TV when plugged in to an outlet has the RED LED standby. Push the power button on the side of the TV, turns the LED BLUE, no backlight, no sound, no video, and no images on screen when you shine a flash light on the screen.

I tested the power supply and I an getting +5 Standby, and all the 24v.

I saw a youtube video where this guy forgot to plug in the LVDS cable and the backlight came on, I've tried this and nothing happens.

Is this a Main board problem, Inverter problem, or Power Supply problem?
Please Help, thank you!!

[gravesent]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

Main board, can't recall exactly what on the board caused it but do recall it being a main in the few i've had like that.

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

Hi gravesent,

Thank you much for the speedy reply and your input.

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

I got a main board from eBay and issue still exist. Does anyone know if the LVDS cable is not connected to the T-Con board will the back light come on?

Another question is I measured OL on couple SMD capacitors shaded in red on the Inverter board, does that mean that it is bad or do I have to desolder them to test it?

[budm]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

'I got a main board from eBay and issue still exist. Does anyone know if the LVDS cable is not connected to the T-Con board will the back light come on?' Yes, it does not care if T-CON is connected or not.
For the backlights to come on it needs the power supply Voltage 24VDC for power and the command signals (BL_ON and the Dim) from the main board.
'Another question is I measured OL on couple SMD capacitors shaded in red on the Inverter board, does that mean that it is bad or do I have to desolder them to test it?' No, it does not mean it is bad, cap will show open circuit when test with Ohm meter, if it shows resistance then it has leakage (Large capacitance cap will show low resistance at first due to the cap being charged by the meter and then you will see very high or OL on your meter). That cap you have marked will usually as shorted circuit when it failed.

[awyatt2]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

check for cold solder joints these sets are full of them esp the 24volt side I had two or three with all the inverter connector pins solder joints bad. the caps on the inverter were also bad very high esr but the joints were the problem. mine was the 32 inch version but it might be worth a look.

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

Bud, thank you for your assistance.

Picture of power supply connector values when powered on.

[vinceroger69]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

If this is a common issue as you say in post 1 there is still a chance your ebay board is faulty maybe worth asking for a refund and trying another as this may of come out a smashed screen set untested etc.

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

Thank you awyatt2.
I went over all the purple shaded area with the iron and solder in some areas. I did not see any cold solder joints on the back of either inverter connections.

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

vinceroger69,

I agree, I have purchased one other main board off of ebay that said the same but was bad.

Seller said the main board came out of a working TV with cracked panel.

[budm]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

Looking at your pictures, I see that the Inverter board has TWO connectors, the CN2 is the one that get the command signals but I can not see how all the boards are connected together. I need to see how the command signals from the main board get to that CN2 connector.

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

Bud,

CN2 is connected to the 24v side of the PSU board then the white and yellow cable goes to CON3 on the parallel port side.

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

Please help, thanks!!

[budm]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

OK, the Yellow wire and the White wire on the inverter board connector are the two command pins, so what do DCV do you have on those two wires with ref to GND?

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

White = 0.057 DCV
Yellow = 2.837 DCV

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

White = 0.057 DCV
Yellow = 2.837 DCV

[budm]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

White = 0.057 DCV is way too low, it is generated by the main board.

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

budm,

The main board has a parallel port that connects to it. i am not sure if main board is sending signal to Inverter board or vise versa.

[budm]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

Main board sends the command signals to the Inverter board.
If you check the resistance between the White wire connector on the Inverter board and the main board connector, one of the pin will show <1 Ohm, same for the Yellow wire.
Inverter does not send any signals to the main board.
The chassis module of the main board/power supply boards has plug that mates with the socket on the chassis.

[TVRepairNoobie]

Re: Polaroid FLM-2632, Blue LED, no sound, no picture, no backlight, cannot turn off

I left the connection to CN2 unplugged, then took a measurement. value is the same 0.057 DCV.