Polaroid P40LCD12 SMPS Voltages Help please

[NipZ]

I have acquired a Polaroid P40LCD12 that stopped working today. The Power LED is just constantly blinking and the tv wont turn on. I removed the back but can not see any indication of voltages on any of the connector points. Can anyone point me in the right direction to a service manual or schematic or help me out with the voltages?
Power supply model number 17PW26-5

Many Thanks

[tom66]

Re: Polaroid P40LCD12 SMPS Voltages Help please

26-4 is very similar, and this schematic has the voltages on it.


Set is made by Vestel - so same as Technika, Sanyo, etc.

Blinking standby light immediately is a protect fault - can be bad firmware or a power supply/main board power supply fault.

[NipZ]

Re: Polaroid P40LCD12 SMPS Voltages Help please

Thanks for the info tom66!

[NipZ]

Re: Polaroid P40LCD12 SMPS Voltages Help please

I've checked voltages from connector PL816 and as soon as I connect the tv to a power outlet voltages are available(see pics) apart from pin13, and this is the same whether I have inverter and mainboard connected or disconnected. Another abnormality is pin 4 SW_SWITCH fluctuates between 8.5v and 8.9v with mainboard connected.

Any help appreciated

[NipZ]

Re: Polaroid P40LCD12 SMPS Voltages Help please

Am I correct in thinking these voltages shouldn't be present until the IR receives a signal which in turn sends a signal from the mainboard to the SMPS to turn on? If so what would I be looking for on the power supply that could be causing this fault, maybe a shorted diode?

[tom66]

Re: Polaroid P40LCD12 SMPS Voltages Help please

That voltage is normal for that line. It's a way for the main board to put the PSU in deep sleep. With the voltage high like that it runs normally.
Problem probably on main board

[NipZ]

Re: Polaroid P40LCD12 SMPS Voltages Help please

Thanks for the info tom66, I hadn't realised some tv's worked by the mainboard putting the psu in a deep sleep. Would my missing 3.3v on pin 13 have something to do with the reason my psu isn't in a deep sleep?

[Daveatfernie]

Re: Polaroid P40LCD12 SMPS Voltages Help please

I have the same TV with a fault. No LED blinking on mine.
(was steered here by another helper)

My PSU when unplugged from the inverter and mainboard only generates 5V on pin 4 and 14 then 3.3V present on pins 15 and 16. None of the other voltages are present (I assume as the mainboard isn't plugged in to ask them to come up)

It sounds as though yours has powered up without the request from the mainboard?