Insignia NS-LCD32 Problems

[koerneka]

Hi all,

Recently I've picked back up on my Insignia 32" LCD. This is the second thread about the TV, as I am still stumped. Original thread:https://www.badcaps.net/forum/showth...nsignia&page=2

Here's the short version: When you plug in the TV, you can hear a faint whine from the power supply. When you turn the TV on, the high pitched sound becomes louder. The LCD displays colored lines that "move" as you press buttons (channel, vol, etc). No sound, no matter how many vol up presses.

As stated in the original thread, I attempted to check the PS voltages, and they came out okay.

Someone else recommended ordering a new main board, which I did. With this board, the exact same symptoms occur. Occasionally, the lines will "freeze" and become brighter - almost too bright. I saw something similar to this on a Polaroid with bad caps... am I onto anything there?

Would a Tcon board cause a no sound situation? Or should I look more closely into the power supply? The fuse FU502 is NOT open. Pictures of the board are in the original thread.

Sorry this is kind of scattered - if you need clarification on anything let me know.

[tom66]

Re: Insignia NS-LCD32 Problems

Those are characteristic of a bad T-con, but I've seen the same from a low 5V rail on a PSU. Can you post some pics of your PSU?

[koerneka]

Re: Insignia NS-LCD32 Problems

Thanks for your reply. In the thread linked in my original thread, post #3 has a picture of the PSU attached. I'm on a mobile phone right now, so I will not be able to re-upload the picture for a while.

Would a bad TCon prevent sound from being produced?

[koerneka]

Re: Insignia NS-LCD32 Problems

Well I tested the voltages on the power supply, with the unit ON. Everything was withing about half a volt of the labeled value. I attached new pictures of the power supply.

I'm a little stumped at this point. Any ideas about the noises the PS makes, as described above?

[koerneka]

Re: Insignia NS-LCD32 Problems

Powering on the TV with the panel disconnected from the Tcon gives a uniform black screen - so it appears that the panel is good. Would removing the LVDS cable from the Tcon tell me anything? I would expect the same black screen. If the cable was partially inserted, I would expect distortion. Sound correct?

I read something about this in another thread.

[tom66]

Re: Insignia NS-LCD32 Problems

If you're getting 4.5V the T-con might not like this. Voltages that are a "bit" low are sometimes signs of bad caps which have dried up and not bulged.

[koerneka]

Re: Insignia NS-LCD32 Problems

Alright. Maybe the squealing noise the power supply makes is another indication? If you think I should try recapping the power supply, I am comfortable with that.

[tom66]

Re: Insignia NS-LCD32 Problems

Alright. Maybe the squealing noise the power supply makes is another indication? If you think I should try recapping the power supply, I am comfortable with that.

Yeah, it is very common to hear a high frequency whining from a PSU either under too much load or one with bad capacitors. What caps are used on it? Looks like JH, I've replaced quite a few of those on the UK version of Insignia TVs (Lexsor.)

[koerneka]

Re: Insignia NS-LCD32 Problems

Yes, they are JH caps. I have ordered replacements for all 12 caps on the board, except the big one. Had to mix Panasonic and Nichicon to avoid backorder. We'll see how it turns out.

[koerneka]

Re: Insignia NS-LCD32 Problems

Alright, well the recap is finished. Still have the whining noise in the power supply, and still have the same lines on the display. I'm thinking it MUST be something with the TCON now?! =\

[mr.sky]

Re: Insignia NS-LCD32 Problems

Alright, well the recap is finished. Still have the whining noise in the power supply, and still have the same lines on the display. I'm thinking it MUST be something with the TCON now?! =\

Do you have a Service Manual or Schematic of the TV.

[Doom2pro]

Re: Insignia NS-LCD32 Problems

The whining is coming from the Power Factor Correction circuit, there is a known bad capacitor located there, it's usually "JH" brand, 50v 47uF... Replace it and the whining will go away, over time it will cause the set to not turn on if it's too cold (it has to be warmed up).

The faulty capacitor is located near the DIP-8 IC (missing one pin).

[RollaGrad]

Re: Insignia NS-LCD32 Problems

Hi all,

I have a similar PSU whine problem. I was given an Insignia lcd-32-07 because it wouldn't power off one time and then it wouldn't turn on. Now, the television will power on after pressing the power button and waiting for a while, however when plugged into the outlet a high pitched noise is heard coming from the power supply. If the TV is turned on the high pitched noise gets louder. I checked voltages on the PSU and am getting the standby voltage of 3.3V.
My large filtering capacitor, which appears to be producing the whine maintains 170V when in standby, and ramps to around 350-400V when powered on as expected. None of my capacitors look bulged, but I was going to try replacing the large 450V 150 uF cap.
My problem is I can't tell if this capacitor is snap-in or not. Also the dimensions of the current capacitor are 30mm in diameter, 26mm in height, and 10mm spacing. Since the back of the TV fits fairly closely to the power supply, I can not use a capacitor that is much longer, but also do not have any more PCB real estate to get anything wider than 30mm.
I have attached pictures of my board, 6HA0112010. Does anyone have insight as to what might be the issue or where I might find the right capacitor? I have attached pictures of the soldered capacitor leads, the 450V 150uF cap, and the PSU. I hope they're clear enough.

Thanks so much! I've been troubleshooting for quite some time.

[dcapper]

Re: Insignia NS-LCD32 Problems

I have the NS-LCDF and I thought it was a cap problem (My ps looks different than yours). I metered all the transistors, diodes, and resistors and I found the 18n50 was blown. It was shorted. I replaced all caps except the large one, the 18n50 and all the ic's. So I thought it was fixed. Lucky I bought 2 of the 18n50's. Anyways powered it up and nothing, same whining, no pic, no backlight and pop goes the 18n50. I had metered the large capacitor before, or at least I thought I did. Anyways it was faulty. I put in a 150uf 450v temporary and the tv worked fine. No whining. I ordered the proper one from digikey, part number 1189-1355-ND. I ordered a cap kit from simoncapacitor on Ebay. I buy all my small caps from him.