I have a Philips 47PFL3603D/F7 with the same problem. It was the IR sensor board causing the problem. You can search online to find the board, which almost everyone will most likely not have in stock, and cant be ordered. The part you need is this: 313926859181 IR Remote Sensor.

Models it will fit are as follows: Substitute Parts 313926859182

Known Models

MAGNAVOX 42MF438B/27

MAGNAVOX 42MF438B/27

MAGNAVOX 42MF438B/F7

MAGNAVOX 52MF438B/27

MAGNAVOX 52MF438B/F7

PHILIPS 32PFL3403D/85

PHILIPS 42PFL3403D/27

PHILIPS 42PFL3403D/F7

PHILIPS 42PFL3603D/27

PHILIPS 42PFL3603D/F7

PHILIPS 47PFL3603D/27

PHILIPS 47PFL3603D/F7

PHILIPS 52PFL3603D/27

PHILIPS 52PFL3603D/F7

If you can find the board, great! A replacement board costs about $12.00. If you can’t… we’ll there is something you can try ; )

Either way, if you know it’s the board, what’s the harm in trying?

Remove the back from the TV. You can actually leave it on your stand to do this if you can spin it around to gain access to the back of it. Be sure to unplug everything first!!!

Looking at the back of the tv, the board will be located in the lower left side by the speaker. It will have 2 cables attached to it. Remove them, and take out the screw or two that holds it in place. There will be a plastic tab that keeps it in place also.

Take your fingernail and bend the tab back, and the board should come free. After that you should be holding the board in your hands. The side of the board with the connectors on it is the side you want to manipulate. There will be a tiny surface mounted capacitor beside one of the wire connection sockets. Take a utility knife and scrape it off/ you could use a soldering iron but it should come off very easy with a knife.

Plug it back in, and give it a try! If it works… great! If not, find a replacement board, and try that.

Hope it helps someone!!!