philips 170s turns on for 1s and than dead

[Audison]

Replaced most of capacitors on the power board but I suspect that the problem is schottky barrier rectifier that makes some weird noise when the lcd turns off. You can keep powering it on and it will just turn off again...

the original one is SB10150FCT
the closes replacement I could found on website I can order parts on is MBR20150CT
will this be an okay replacement?
also is it smart to replace other rectifiers there are 2 more Yg802c06 and k3562

Thanks!

[budm]

Re: philips 170s turns on for 1s and than dead

The question is, did the two Voltages drop out when it urns off?
And you say it turns OFF, Does the Power LED go off or changes color? Or it actually goes into Standby mode?
Good clear pictures of the board?
What test did you do on the suspect diode?
What Voltage test did you do so far?

[Audison]

Re: philips 170s turns on for 1s and than dead

The question is, did the two Voltages drop out when it urns off?
And you say it turns OFF, Does the Power LED go off or changes color? Or it actually goes into Standby mode?
Good clear pictures of the board?
What test did you do on the suspect diode?
What Voltage test did you do so far?

I will provide you with everything tomorrow. The lcd is at friends place where we repair stuff. The LCD power led goes off so it is definitely powered off. You have to turn it on again to start it it's not standby. I will get you some images tomorrow. We did not test anything as we are very new at repairing electronics. Any tips are appreciated! Thanks!

[Darel-S]

Re: philips 170s turns on for 1s and than dead

posting pic for my friend o7

[Audison]

Re: philips 170s turns on for 1s and than dead

The question is, did the two Voltages drop out when it urns off?
And you say it turns OFF, Does the Power LED go off or changes color? Or it actually goes into Standby mode?
Good clear pictures of the board?
What test did you do on the suspect diode?
What Voltage test did you do so far?

Pictures are up where do we measure when we turn the lcd on?
The diode sb10150fct is making the weird sound that is why we though it's bad.
Thanks for your help!

[budm]

Re: philips 170s turns on for 1s and than dead

We need straight shot pictures of Top and bottom side of the power supply board.
Do you hear weird sound if the Main board is not connected to the power supply board?

[Audison]

Re: philips 170s turns on for 1s and than dead

We need straight shot pictures of Top and bottom side of the power supply board.
Do you hear weird sound if the Main board is not connected to the power supply board?

The sound is made when the lcd powers off after 1 sec that is on than you hear that weird sound.

[budm]

Re: philips 170s turns on for 1s and than dead

Try it without the main board connected to the power supply board to see if it still making noise, this power supply is an always on power supply, it runs 24/7 the minute you apply AC power to the board.
I need the pictures to be able to give you the Voltage test points to see if the Voltages are OK or not.

[budm]

Re: philips 170s turns on for 1s and than dead

Do you have tools to test the diode and Voltages?

[Darel-S]

Re: philips 170s turns on for 1s and than dead

Do you have tools to test the diode and Voltages?

Actually now that I tried only the power supply I think the sound is coming from something else. And ye we have a multimeter, I hope the pics are ok now, we're still learning but were getting there slowly xD, Ty for your time

[Joe Black]

Re: philips 170s turns on for 1s and than dead

Here's your shematics:
https://cdn.badcaps-static.com/pdfs/...813255e9d9.pdf

Here's a video of a guy doing work on that particular board, while trying to explain some basic stuf:
https://www.youtube.com/watch?v=FYoS13Ox214

[Darel-S]

Re: philips 170s turns on for 1s and than dead

Here's your shematics:
https://cdn.badcaps-static.com/pdfs/...813255e9d9.pdf

Here's a video of a guy doing work on that particular board, while trying to explain some basic stuf:
https://www.youtube.com/watch?v=FYoS13Ox214

Thank you that actually helped me a lot, but sadly we don't have that same problem, I measured those two transformers and they are fine. I measured almost everything on the board and the only thing I don't know if its ok, are the two diodes the SB10150FCT reads 250 and the other one YG802C06 is 150. (I even took them out to be sure)

I tried to connect only the board too and it was buzzing, the output was fine, 5v and 12v.. sooo.. Im lost xD

If those 2 diodes are fine then it must be something else

[budm]

Re: philips 170s turns on for 1s and than dead

Thank you that actually helped me a lot, but sadly we don't have that same problem, I measured those two transformers and they are fine. I measured almost everything on the board and the only thing I don't know if its ok, are the two diodes the SB10150FCT reads 250 and the other one YG802C06 is 150. (I even took them out to be sure)

I tried to connect only the board too and it was buzzing, the output was fine, 5v and 12v.. sooo.. Im lost xD

If those 2 diodes are fine then it must be something else

So let me get this correctly, you do have 5V and 12V when the main board is not connected to the power supply/inverter board combo, but you do hear loud buzzing sound from the board, right?

[Darel-S]

Re: philips 170s turns on for 1s and than dead

So let me get this correctly, you do have 5V and 12V when the main board is not connected to the power supply/inverter board combo, but you do hear loud buzzing sound from the board, right?

yes thats right (the sound its coming around the big transformer no idea where exactly). I didn't measure with everything connected tho

[Audison]

Re: philips 170s turns on for 1s and than dead

budm any advice? we still trying to fix this monitor... let us know what needs to be replaced to get this monitor working again. Thanks

[Darel-S]

Re: philips 170s turns on for 1s and than dead

ok made some progress I guess.... I should have checked that from the start tho... the screen is working only the backlight dies so that probably narrows it down quite a bit, but I still have no idea what to check on the board to find out whats wrong :S

[Audison]

Re: philips 170s turns on for 1s and than dead

How do you even edit thread title on this forum? Looked everywhere and I can't find the option to do it. The title is misleading now that we know that the back-light is the problem and it does not power completely down. What is interesting is that the power led goes off at the same time...

[Audison]

Re: philips 170s turns on for 1s and than dead

How do you even edit thread title on this forum? Looked everywhere and I can't find the option to do it. The title is misleading now that we know that the back-light is the problem and it does not power completely down. What is interesting is that the power led goes off at the same time...

Correction power led stays powered on just the back-light dies. Sorry for confusion.

[Audison]

Re: philips 170s turns on for 1s and than dead

Measurements of transformers and connectors for the monitor back light. It outputted 5v for a brief second when the back-light turned on and than it dies. Transformers show 0V if there is power applied...

[Audison]

Re: philips 170s turns on for 1s and than dead

Update: We gave up on fixing the back-light inverter as we are too stupid to figure it out.
So we used a led strip for back-light instead

Perfect fit.
Testing strip

Looks good enough better than previous lamp light


Back-light fixed but now it looks like we have another problem

Only half of the screen is displaying image. We were very stupid to not test this before we even started fixing this display. I can speculate that the panel was working before we started fixing it and only back-light was a problem. Could it be a assembly problem that we connected something badly or something else? Ignore the "transparent" line down the screen on the right that was also when the screen was working with back-light but left part of the screen it's a new problem. We were careful when disassembling everything and assembling back...
Any advice how to fix this?

Thanks