insignia ns-32lcd

[monopoly96]

Hi I have an insignia ns-32lcd with no picture or sound when it is plugged in only the red standby led blinks and will not change even with the power button pressed. Power supply voltages are correct when board c is disconnected (pics below) but when it is connected the 24v output fluctuates from 24 down to about 9 and back up again in sync with the standby light. I know the power supply is good since I know a friend with the same tv and I tested with that, still the same problem. Any ideas on how to fix this?

[monopoly96]

Re: insignia ns-32lcd

thought pictures were attached but forgot to hit upload, here they are

[monopoly96]

Re: insignia ns-32lcd

anyone have an idea on what could be wrong?

[dcapper]

Re: insignia ns-32lcd

Wish I could help you. I have the same tv with a blown 18N50. Mine is definitely the psu but yours seem to be more in depth of a trouble.

[dcapper]

Re: insignia ns-32lcd

Actually you could have a psu problem. You have power hooked up with no draw and the voltages are correct. But once a draw is on it drops. You could have a bad cap not holding the charge. Look at your caps. I would replace all of them. My 18N50 is completely shorted and it blows the fuse so I have to replace it.

[monopoly96]

Re: insignia ns-32lcd

Thanks for your response! Thats what I thought at first and replaced all the caps, but the problem was still there so i borrowed a friend's tv's psu and it did the same thing so i'm thinking the main board could have a problem with how its activating the primary on the psu since without it plugged in the 24v pins are 0 and with it they go from 24 down to 9 whenever the standby light blinks and back up to 24. Any other ideas would be much appreciated since i've got no clue what could be bad specifically.

[budm]

Re: insignia ns-32lcd

OK, that large black main filter cap, measure the voltage RIGHT AT THE TWO LEGS of the cap, it should go up from 170V to around 370~400VDC when power switch is activated (PS_ON signal from the main board will turn on the PFC Voltage booster and the 24vdc power supply).

[monopoly96]

Re: insignia ns-32lcd

Alright the large filter cap reads 290v before and after the on button is pressed and fluctuates down to about 275v in sync with the 24v fluctuations. It seems like it ignores the power button completely. Without any board plugged into the psu the large cap reads 170v.

[tom66]

Re: insignia ns-32lcd

Sounds like you have a PFC circuit fault, the most likely suspect would be the 450V capacitor.

[vinceroger69]

Re: insignia ns-32lcd

Thanks for your response! Thats what I thought at first and replaced all the caps, but the problem was still there so i borrowed a friend's tv's psu and it did the same thing so i'm thinking the main board could have a problem with how its activating the primary on the psu since without it plugged in the 24v pins are 0 and with it they go from 24 down to 9 whenever the standby light blinks and back up to 24. Any other ideas would be much appreciated since i've got no clue what could be bad specifically.

so your freinds psu is working in his set ok? but when you put his working psu into your set it plays up just like your own psu does.

[monopoly96]

Re: insignia ns-32lcd

In response to vinceroger yes, so i'm pretty sure it isn't the psu being the problem especially since it works like its supposed to (to my knowledge) without the main board plugged in. Since the on button and remote seem to do nothing could it be a problem with the main board?