Insignia 32" LCD TV Model# NS-32LCD

[Paul678]

Re: Insignia 32" LCD TV Model# NS-32LCD

Did you replace the other small cap?

WOW. MOTHER-FUCKER!!! THAT WAS IT!!

How did you boys get so badass!!!

I ain't no homo, but I'd like to kiss you!!!



Ok, I've settled down now.... It's really amazing how
many electrical systems are taken down by ONE goddamned
component! I just measured it on my cheapie built-in capacitance
meter on one of my DMM. The highest range is 20uF, so
I was expecting to see over-scale for a 47uF cap...guess what?
Only 6.7uF!!!!! HA!

The chain is only as strong as the weakest link, AMEN.

Much thanks to Bud and Tom for guidance....you boys
just saved me $35!!!!!

[tom66]

Re: Insignia 32" LCD TV Model# NS-32LCD

Awesome . Sometimes a tiny cap like that can seem so very important. I just had the same problem with an external plug pack; the difference was after about 10 minutes of letting it sit, it did fire into life, but otherwise the output would just pulse on and off, and with any significant load it wouldn't do anything.

I bet if you tested it for ESR, it would be way out, but if either capacitance or ESR are off, it can cause problems. ESR is less critical for those caps, but it's still important.

What cap did you use to replace it?

[Paul678]

Re: Insignia 32" LCD TV Model# NS-32LCD

Awesome . Sometimes a tiny cap like that can seem so very important. I just had the same problem with an external plug pack; the difference was after about 10 minutes of letting it sit, it did fire into life, but otherwise the output would just pulse on and off, and with any significant load it wouldn't do anything.

I bet if you tested it for ESR, it would be way out, but if either capacitance or ESR are off, it can cause problems. ESR is less critical for those caps, but it's still important.

What cap did you use to replace it?

Remember that 480 Vizio I had, that you didn't think
was really worth repairing? I tried selling the power
supply "for parts, as-is" on Ebay, but never sold it.

So I started stealing caps from it this week! haha!
Definitely helps to have a stash of old boards!

It was a 47uF @ 50V. The original cap was 25V, so
it should be fine. Don't know what the brand was.....

But you've just shown how some experience can
save you money, because there are many output
caps that I could have replaced, if I wanted to replace
all the caps, in a "shot-gun" repair job. Actually, if
I was really serious about doing a SERIOUS repair,
that's what I would do, but I'm too cheap! Those
caps can add up!!!!

I'm considering getting a Fluke DMM like Bud's, which
has a bar graph, which would have saved me time,
because I would have seen the fluctuation of the
voltage. That's virtually like a very simple o'scope.

But thanks for helping to pay my rent, dude!!! haha!!

[budm]

Re: Insignia 32" LCD TV Model# NS-32LCD

Great news, but I thought you tested the cap and they were OK as far as the value wise.
If the main cap failed, you will have high AC ripple on top of the DC, but will not damage the PFC since PFC will be charging the main cap by the PFC boosting circuit through boosting Diode, see the diagram when that cap is charged up to higher than 170Vdc the top Diode will be turn off.
By the way, I usually do not bother to look at the thread when it is long thread, but I m glad I did.
By the way, heat up the bad caps with hair dryer and see if the value goes up.

[tom66]

Re: Insignia 32" LCD TV Model# NS-32LCD

Great news, but I thought you tested the cap and they were OK as far as the value wise.
If the main cap failed, you will have high AC ripple on top of the DC, but will not damage the PFC since PFC will be charging the main cap by the PFC boosting circuit through boosting Diode, see the diagram when that cap is charged up to higher than 170Vdc the top Diode will be turn off.
By the way, I usually do not bother to look at the thread when it is long thread, but I m glad I did.
By the way, heat up the bad caps with hair dryer and see if the value goes up.

I'm just going by what has been seen with Vestel TVs.

For the PFC the cap looks like a dead short. So when the inductor is "charged" by the FET, the "discharge" occurs through the diode and the cap is charged up: all is well and good.

However if the cap is open circuit, the discharge can't go anywhere (the current can't be immediately interrupted through the inductor) so it forms a large voltage spike, damaging the diode and potentially the FET. This usually blows the fuse too.

[Paul678]

Re: Insignia 32" LCD TV Model# NS-32LCD

Great news, but I thought you tested the cap and they were OK as far as the value wise.
If the main cap failed, you will have high AC ripple on top of the DC, but will not damage the PFC since PFC will be charging the main cap by the PFC boosting circuit through boosting Diode, see the diagram when that cap is charged up to higher than 170Vdc the top Diode will be turn off.
By the way, I usually do not bother to look at the thread when it is long thread, but I m glad I did.
By the way, heat up the bad caps with hair dryer and see if the value goes up.

Well, the funny thing is that for some strange reason, the cap
at fault was covered in shrink-wrap tubing, so the value
was hidden from me. Foolishly, I assumed it was about the
same value as the other small cap, about 10uF, so when I
measured somewhere around 8uF, I wasn't alarmed.

Also, my capacitance meter is an ultra cheap unit built into
a DMM, so measurement repeatability can be an issue.

I'm considering getting a Fluke like the one you have, because
if I had seen the fluctuations on a bar-graph, I would have
saved time I wasted uncovering and measuring the
inverter and the main board.

Looking at your diagram, it looks like when the main cap
is higher than 170V, DC and low frequencies from the
rectifier are shunted to ground, while the higher harmonics
are blocked by the inductor, and pass through the top diode.
Then if there is a sudden load that draws a lot of current
from the main cap, the switch turns off, and the energy
stored in the magnetic field of the inductor is allowed to
help re-charge the cap through the bottom diode.

[budm]

Re: Insignia 32" LCD TV Model# NS-32LCD

The inductor and the lower diode are the one that produce the booster voltage, the Top diode will be bias off, by the way we use this similar circuits (no filter cap) to generate the pulses needed for testing our equipment.

[ajsemtb]

Re: Insignia 32" LCD TV Model# NS-32LCD

Hey all, just fyi I still haven't fixed my tv. Work has prevented a lot of trouble shooting time but I ordered a replacement power supply and logic board ( the board w the heat sink) installed that last night and it still didn't come on.

[selldoor]

Re: Insignia 32" LCD TV Model# NS-32LCD

@Ajsemtb
As you have a new power supply and a new logic board
how about starting over perhaps even on a new thread. I dont normally suggest that but a completely fresh look might show something missed.It will be more work for you but save people looking back 6 pages of stuff that might be largely irrelevant due to the board change.
Call it Insignia Model# NS-32LCD New Boards fitted
It will also save me having to see that dreadful statement by paul 678 again

[Doom2pro]

Re: Insignia 32" LCD TV Model# NS-32LCD

I have an Insignia 23 inch LCD and the symptoms were when the TV was cold if I pressed the power button the set would not turn on and if I held down the power button the Green LED would turn on then off, over and over, and I would hear a faint whining sound from the PSU. Keeping this up would eventually cause the set to turn on, and a noticeable high frequency whining sound would be heard while it was running. A hair dryer would get the TV on quicker, so it was obviously temperature related. If the set was turned off after running a while, it would turn back on no problems, however if it was left to cool down, it would require holding the power button down for five minutes or more, or using the above mentioned hair dryer trick.

I tried replacing all the secondary caps, SMD Glass MELF diodes (they can crack and cause intermittent issues, thermally effected), I touched up the solder joints on everything (I mean EVERYTHING, even SMD parts). Nothing seemed to work and I didn't have any canned air to chill components so I was left guessing, replacing suspected components and retesting.

Eventually I had an idea to get a ziplock bag and fill it with ice chips. So I went around chilling various parts to try and replicate the problem of turning the set on.

I eventually narrowed it down to a certain "JH CD263" 105C 50v 47uF electrolytic near the Power Factor Correction circuitry. I swapped it for a spare (Nippon Chemicon brand) and set turned on immediately and no more high frequency whining sound, also worked when entire power supply board chilled in freezer for 10 minutes (just to be sure).

I tested the capacitor on my meter and it read about 6.7uF and when I applied a 24V charge to it, the voltage would drop rapidly when the voltage source was removed, also discharging it when fully charged would not provide any "spark", while another working capacitor of same voltage and value would create quite the snap. So this tells me the ESR went WAY up, and AL Electrolytic caps are negative temperature coefficient so that would explain the ESR going down when the capacitor was warmed up.

Set works fine still.

[budm]

Re: Insignia 32" LCD TV Model# NS-32LCD

Hair dryer is a great tool to use for locating bad caps if they are not too far gone. For example:
https://www.badcaps.net/forum/showth...ghlight=AL2416

[dcapper]

Re: Insignia 32" LCD TV Model# NS-32LCD

I have a Prima with the same power supply. I measured all the caps and I found a cap reading 16uf. I thought it might have be a 10uf cap since it had a heatshrink over it. But like a poster above I replaced it and the tv is working perfectly. I'm ordering all new caps just so I won't have to tear it apart again.

[Dmoney1]

Re: Insignia 32" LCD TV Model# NS-32LCD

I also am the lucky owner of a insignia ns-32LCD tv. The problem I am having is as soon as the tv is plugged in the insignia light flashes from red for 2 seconds then to blue for 4 seconds and never stops. The power button has no effect. I have read through the previous posts and started at the power supply. I have tested the pico fuses,glass main fuse and removed and tested the 2 47mf caps, a 10mf cap near the main cap and also the main cap itself. All caps within specs. All caps also look undamaged visually.

I also temporarily disconnected the button panel to test if the power button was stuck on but it had no effect

As far as the voltages at the ribbon cable connections on the power supply. Where I should have 5v I have 5.06v stable. All the pins where the 24v should be i do have 24.67v but, the voltages are all dropping to 10.5v in unison with the insignia power light.
I am stuck at this point
Any help would be greatly appreciated!

[xtal]

Re: Insignia 32" LCD TV Model# NS-32LCD

I have a Legend model LC3226L ,, I failed 2 months ago and made ticking sound.
The next day it was working. Three days ago it crapped again....After finding this forum I was able to get it repaired,,, I replaced the 2 small caps , however it still would not work, but it did start showing the red standby bar. After more checking I found fuse 2 [ H@5A ] was open ,, I replaced it with a mini fuse and a pigtail fuse holder ,,, it worked ... after reassembling,, it stopped working.. I dismantled, checked the 5 amp fast blow fuse I had added, it was ok. further checking, I found one pig tail had a bad solder joint, now all ok...
It was a pretty blob of solder on the wire, but was loose contact with the copper trace...

Also with fuse 2 open my large cap showed 275 volts with Fluke DVM..
With fuse replaced I measured 260 volts and set working...

FYI fuse 3 is H@T7A
my power board is 782.32FB26-2000 2006 07.25 V00

[xtal]

Re: Insignia 32" LCD TV Model# NS-32LCD

I used local RS caps, fuses, pigtail holder,
The pigtail hold sucks, but it did work.

With any luck the parts will hold up

[AVPLUS11]

Insignia ns-lcd32. loud screech from spkrs

hooked up to a dvd player thru composite 1 input. Unit comes on with pix, but has a loud screech coming from the speakers. then it will shut off. I'm suspecting smd caps om the main. I've gone thru with my cap meter, and cannot find any bad readings.

[selldoor]

Re: Insignia 32" LCD TV Model# NS-32LCD

What does it do with other inputs?

[Shane711]

Re: Insignia 32" LCD TV Model# NS-32LCD

Thank you for this web site again. Thanks to tom66 and budm. I had the same problem that Paul678 had. The cap that was cover in shrink wrap was a 47uf 25v and was reading 25uf. I replaced it with a 47uf 50v and the TV works perfect now. But I did not see this mentioned, my power board was making a clicking noise. Sounded like a spark/ark. I was suspecting it was the transformer but of course after reading this thread I found it to be the tiny cap. The voltage was jumping all over the place. Also I had several broken solder joints on the bottom of the power supply board so if anyone is reading this be sure to check for that to.

[budm]

Re: Insignia 32" LCD TV Model# NS-32LCD

That clicking noise is due to the circuit was stuck in the on and off cycle due to bad startup cap, it could not stay on due to bad cap.

[Shane711]

Re: Insignia 32" LCD TV Model# NS-32LCD

I can't seem to start a new thread. I have a tube TV, Sony kv-36fv15 and the picture turns off and on. So I read online that the tube is getting old. Turning up the screen voltage seems to fix this problem but I never done this before. On the flyback transformer there is focus and screen. I believe I turn (Screen) to the right. Can someone confirm that this is the right way to turn up the voltage? And maybe because I am a new member I can't seem to start a new thread, I don't know why I can find it. Thank you.