Philips HTL2160 soundbar NO power problem

[DjKrish]

This soundbar has a blown AC/DC Offline Switcher IC which is top257en. I replaced it, power restored, can on the unit and sound works fine. After a while, turn it off, and turn it back on again by pressing the power button, the IC blows again Replaced it again, it blows again after playing with the power button ON and OFF a few times. If the power board is not connected with the main board, its not blowing. It only blows when in operational mode. I suspect it could be the ceramic caps and possibly the electrolytic caps as well. Any suggestions? 19V present (according to service manual) on the output pin that's connection to the main board which states 18V. I believe the AC side is working fine as the fuse is not blowing. Its definitely something to do on the DC side thats blowing the IC.

Already tested all the diodes, all in good order

[Andrew F. Ali]

Re: Phillips soundbar NO power problem

On both the Top and Bottom sides, test all the semi-conductors . Test the e-caps ESR and capacitance and NP caps capacitance. Test the resistors for open or high resistance ohms. Do not take for granted nothing is wrong on the ac side. Test all the components on the ac side as well. Report your findings.

[stj]

Re: Phillips soundbar NO power problem

my distant past involved a lot or repairs with topswitches,
99% of them died because a small electrolytic capacitor had dried up.

[DjKrish]

Re: Phillips soundbar NO power problem

my distant past involved a lot or repairs with topswitches,
99% of them died because a small electrolytic capacitor had dried up.

I will pop out all the electro caps and check them all

[DjKrish]

Re: Phillips soundbar NO power problem

On both the Top and Bottom sides, test all the semi-conductors . Test the e-caps ESR and capacitance and NP caps capacitance. Test the resistors for open or high resistance ohms. Do not take for granted nothing is wrong on the ac side. Test all the components on the ac side as well. Report your findings.

Ok will test all the components tonight and revert back.

[DjKrish]

Re: Phillips soundbar NO power problem

https://www.youtube.com/watch?v=whF0jGZeNHs

Changed the TOP IC, changed 2 ceramic caps thats connected to the IC. Tested all electro caps and they are fine. Right now if power up as standalone, the power supply is fine but im afraid to hook it up to the main board afraid of blowing up the last TOP i have See the video, the voltage is not constant, it moves up and down

[CapLeaker]

Re: Phillips soundbar NO power problem

my distant past involved a lot or repairs with topswitches,
99% of them died because a small electrolytic capacitor had dried up.

That's where I put my money too, or a cold solder / improper solder joint somewhere.

[budm]

Re: Phillips soundbar NO power problem

Check the snubber cap C531 and the snubber diode right next to the C531 to make sure they are OK.

[stj]

Re: Phillips soundbar NO power problem

how did you test the caps?

[momaka]

Re: Phillips soundbar NO power problem

https://www.youtube.com/watch?v=whF0jGZeNHs

Changed the TOP IC, changed 2 ceramic caps thats connected to the IC. Tested all electro caps and they are fine. Right now if power up as standalone, the power supply is fine but im afraid to hook it up to the main board afraid of blowing up the last TOP i have See the video, the voltage is not constant, it moves up and down

Test with an incandescent bulb in series with the line - that way, if something goes too out of whack, the TOPswitch shouldn't blow up. Details how to wire the incandescent bulb here:
https://www.badcaps.net/forum/showpo...4&postcount=70

[DjKrish]

Re: Phillips soundbar NO power problem

how did you test the caps?

With a cap meter

[DjKrish]

Re: Phillips soundbar NO power problem

Check the snubber cap C531 and the snubber diode right next to the C531 to make sure they are OK.

Already replaced C531 and C536. The diode is fine no short.

[DjKrish]

Re: Phillips soundbar NO power problem

Test with an incandescent bulb in series with the line - that way, if something goes too out of whack, the TOPswitch shouldn't blow up. Details how to wire the incandescent bulb here:
https://www.badcaps.net/forum/showpo...4&postcount=70

Will try this and update here later

[budm]

Re: Phillips soundbar NO power problem

Already replaced C531 and C536. The diode is fine no short.

It looks like you have blown snubber resistor R565.
That snubber cap C531 should be rated at 1KV, you have 400V rating on that replacement cap.

[DjKrish]

Re: Phillips soundbar NO power problem

It looks like you have blown snubber resistor R565.
That snubber cap C531 should be rated at 1KV, you have 400V rating on that replacement cap.

The original snubber cap is rated as 2200 J 400. What you see in the picture is actually original according to Phillips schematic diagram

[CapLeaker]

Re: Phillips soundbar NO power problem

It looks like you have blown snubber resistor R565.
That snubber cap C531 should be rated at 1KV, you have 400V rating on that replacement cap.

good eyes budm

[budm]

Re: Phillips soundbar NO power problem

The original snubber cap is rated as 2200 J 400. What you see in the picture is actually original according to Phillips schematic diagram

Well, they are not following the IC manufacturer advice.
the schematic shows two 22 Ohms resistors in parallel so one is not going to handle it, your board only has one, cutting corner to save money on parts. The snubber diode is rated at 1000V too.

[DjKrish]

Re: Phillips soundbar NO power problem

Well, they are not following the IC manufacturer advice.
the schematic shows two 22 Ohms resistors in parallel so one is not going to handle it, your board only has one, cutting corner to save money on parts. The snubber diode is rated at 1000V too.

So i should change the Cap and add one more 22 Ohms? Should that be ok?

Update: After replacing the burned resistor, the main cap is discharging pretty quick upon switching off. Before this nah, wasn't discharging at all. The voltage seems stable as well. The schematic says 19V, the board says 18V. Weird.

2nd update : Fixed everything and installed the full unit. So far nothing exploded yet as its working fine, fingers crossed

[budm]

Re: Phillips soundbar NO power problem

I would change the cap to 1000V, the 22 Ohms should be higher Wattage otherwise it will probably burn up again. That snubber circuit is design for reducing the Ringing/Overshoot based on the circuit as a whole, so the only way to find out is to use the scope and a differential probe to analyzing what is going on.

[jazzie366]

Re: Phillips soundbar NO power problem

This soundbar has a blown AC/DC Offline Switcher IC which is top257en. I replaced it, power restored, can on the unit and sound works fine. After a while, turn it off, and turn it back on again by pressing the power button, the IC blows again Replaced it again, it blows again after playing with the power button ON and OFF a few times. If the power board is not connected with the main board, its not blowing. It only blows when in operational mode. I suspect it could be the ceramic caps and possibly the electrolytic caps as well. Any suggestions? 19V present (according to service manual) on the output pin that's connection to the main board which states 18V. I believe the AC side is working fine as the fuse is not blowing. Its definitely something to do on the DC side thats blowing the IC.

Already tested all the diodes, all in good order

Are those caps on the board branded, "ZHN"? They look to be questionable.
Also, I've seen all the other replies, but just because of the branding im concerned.