Philips 47PFL4606 Powers on, works normal then powers off after a minute

[simwalsh]

Hi,
I am new to this forum and have searched for some answers with problems similar to mine.
Philips TV powers on as normal for about a minute or less then click and no power at all not even standby light. If i disconnect from mains and reconnect it will power on again but for a shorter time. Once i leave it disconnected from main for a longer time it will power on for a longer period the next time.

It sounds like a power supply issue?

I have the board out and want to run some tests. Not sure what i should be doing but i put a 1k resistor across SB and +5v and tested 12v and 24v. Both 24V and 12V slowly go down while i'm reading them,12V never gets to 12V and quickly goes down. blue LED901 stays on for a few seconds and then dies.

Any tips on what could be wrong or what to try next?

Many thanks.

[simwalsh]

Update: did some further tests

When turn power supply on with 1k resistor SB/+5V, across C907 i get over 327v dc then 400v then 327v after 3 seconds or so and when blue led goes off.

At IC902 VCC pin 8 is 9.62V, across C946 i get 9.6V

[simwalsh]

ok thanks for the help here. /s

For anyone that sees this message i fixed it by replacing IC905.

[nomoresonys]

I would have helped but didn't see the post, might have helped to bump it every so often. Oh well, the last time I figured something out without any help I felt better than if it would have been spoon fed to me, anyway, good work.

[simwalsh]

I would have helped but didn't see the post, might have helped to bump it every so often. Oh well, the last time I figured something out without any help I felt better than if it would have been spoon fed to me, anyway, good work.

no worries. i got the answer from someone with the same problem on another forum just took a little bit of digging, i wouldn't be able for advanced electronics