Insignia NS-LCD32 2007 lines on the right

[budm]

Just fixed this TV. The symptom is it has backlights but no pictures or on screen menu, color lines on the right side of the screen.
I knew it has to be something on the T-CON, it is either not getting the VCC to the board or something on the board itself since it has no pictures or menu.
Check fuse and 5V feeding the board are OK, checked the 1117-3.3 and 1117-2.5 (3.3 is good, but the 2.5 is only reading 0.6v), Ohm it out to see if ts feeding shorted circuits, the Ohm reading is about 350 Ohms (due to the network resistors for the 2.5v output setting), remove the IC, Ohm the output pad to ground, it shows 30K. Replaced the 2.5V IC, now it is working again, half hour job. Letting it burns in right now.
More pictures here:
http://s807.photobucket.com/albums/y...-LCD32%202007/

[Jasgriff]

Re: Insignia NS-LCD32 2007 lines on the right

Another good job.

Bonus points for a short of the Fluke 87!

In a few years there will probably be a site called www.badvoltageregulators.net!

[budm]

Re: Insignia NS-LCD32 2007 lines on the right

That is my new FLUKE 187!, I still have the Fluke 87.

[Jasgriff]

Re: Insignia NS-LCD32 2007 lines on the right

It says broken on it. Was it one u repaired? One day we are going to get someone posting a pic of their TV or monitor and it will have bud written all over it :-)

[tom66]

Re: Insignia NS-LCD32 2007 lines on the right

Nice fix! I had essentially the same problem with a Samsung 40" LCD and it turned out to be a low 2.5V regulator too. (On mine the whole screen was covered in lines.)

[tibimakai]

Re: Insignia NS-LCD32 2007 lines on the right

Nice fix budm!
I had an easy fix myself yesterday, slave inverter chip, though I haven't changed anything else or did not do the "fix" either. A half an hour job, while my wife prepaired the lunch
Do you guys pick up this kind of brands also, like Insignia, Apex, Dynex, etc.?
I try to pick up only better/known brands.
Once I picked up a 37" Scott and found out that had the same exact panel needed in a 37" Philips which had a broken screen(my first TV found at the dumpster which started it all) and just swapped it and sold the Philips instead.
It's worth picking up these cheap brands? I found a 40" Apex for $25 and I don't know if I should pick it up or not.
How is the new meter? Eventually I want to get something like that myself, but I'm not sure which Fluke, there are so many out there.

[budm]

Re: Insignia NS-LCD32 2007 lines on the right

The Fluke187 was broken, all the voltage readings were 1/2 off what it should be. It was donated for recycle since Fluke wants almost as much to fix it to buy a new one, so I get to have it and I fixed it, it has one burnt up resistor on the board. I will need to calibrate it, right now all the readings are the same as my FLUKE87.
These 1117-xx series must be bad design or something, I hardly see any LM 78XXX/79XXX/317 failed (you can put dead shorted on them and they just go into shutdown).
It is strabge that you will see just some lines on the screen likethat when the Main chip on the T-CON does not get enough voltage.
@tibimakai, used FLUKE87 is a good start.

[tom66]

Re: Insignia NS-LCD32 2007 lines on the right

These 1117-xx series must be bad design or something, I hardly see any LM 78XXX/79XXX/317 failed (you can put dead shorted on them and they just go into shutdown).

I think the thermal limits for the 1117's are too liberal, such as to allow for cheap designs. The lifetime of a semiconductor approximately halves for every 10C rise. Engineer, under pressure from manangement, runs the LDO at 130C junction-case - thinks they're really clever saving 50 cents over a low-temp efficient switcher or even a bigger LDO. Maybe device is 150C rated at a MTTF of 5,000 hours. So the chips on average fail after 20,000 hours -> ~2.3 years. Also, a 78xx needs a 2V in-out difference, so for any substantial current, it needs a heatsink, and once you get a heatsink, there's little cost to make it a better heatsink. Also remember that CMO, the LCD maker, doesn't care if the LCD lasts, as they aren't responsible for replacing it. In fact it's probably good to increase sales.

I saw on an LG schematic for a plasma TV the prices of each component were accidentally included and it was $0.06 for the 1117's.

Rather strangely on the Samsung I repaired it did fire up once with a good picture on the screen. I figure the regulator was walking wounded and was able to work by chance.

It is strabge that you will see just some lines on the screen likethat when the Main chip on the T-CON does not get enough voltage.

I guess the 2.5V is used to power the main processing core (to allow for smaller transistors, hence more on same size die), and the 3.3V is used to control the output drivers. So any fault in core will cause it to send random signals turning on random lines.

I still don't fully understand the operation of that IC. Does it directly drive the panel (driving positive and negative TFT ON/OFF voltages), or just control the drivers on the LCD?

[budm]

Re: Insignia NS-LCD32 2007 lines on the right

I sure like to see the schematic of the T-CON board (any brand, since the basic operations are about the same) to get more details on how it works.
teh 2.5V regulator was for the Main IC on that T-CON board.

[tibimakai]

Re: Insignia NS-LCD32 2007 lines on the right

sorry to be off topic, but since we arte talking about Fluke meters can I ask if it's OK to buy a used meter?
How can I be sure that it's a good meter? I have found a 179 for $150.

[tom66]

Re: Insignia NS-LCD32 2007 lines on the right

I sure like to see the schematic of the T-CON board (any brand, since the basic operations are about the same) to get more details on how it works.
teh 2.5V regulator was for the Main IC on that T-CON board.

I expect that it is proprietary.

Modern ICs usually have dual supply rails - one for core voltage, the other for IO voltage. Sometimes a third for analog.

[retiredcaps]

Re: Insignia NS-LCD32 2007 lines on the right

The Fluke187 was broken, all the voltage readings were 1/2 off what it should be.

Hmm, if the owner of the Fluke 187 was the original owner and registered the multimeter with Fluke, it should have their famous lifetime warranty and gotten fixed for free.

It was donated for recycle since Fluke wants almost as much to fix it to buy a new one, so I get to have it and I fixed it,

it has one burnt up resistor on the board.

Which resistor was it?

50,000 count!

[retiredcaps]

Re: Insignia NS-LCD32 2007 lines on the right

sorry to be off topic, but since we arte talking about Fluke meters can I ask if it's OK to buy a used meter?

All my multimeters, which include Fluke, were purchased used. If you can buy locally and test it beforehand, that is the safest way to get a working one.

How can I be sure that it's a good meter? I have found a 179 for $150.

With patience, you can get the Fluke 179 or 87 for around $100. See

https://www.badcaps.net/forum/showpo...1&postcount=66

[budm]

Re: Insignia NS-LCD32 2007 lines on the right

Here is Fluke warranty deatails:
"Industrial Products Limited Lifetime Warranty
Lifetime is defined as seven years after Fluke discontinues manufacturing the product, but the warranty period shall be at least ten years from date of purchase. *(Lifetime Warranty applies to products manufactured after October 1996). The warranty does not cover manuals, fuses, disposable batteries, damage from neglect, misuse, contamination, alteration, accident or abnormal conditions of operation or handling, including failures caused by use outside of the product's specifications, or normal wear and tear of mechanical components. This warranty covers the original purchaser only and is not transferable. This warranty covers the LCD for 10 years only (state-of-the-art for LCDs). To establish original ownership proof of purchase is required (20, 70, 80, 170, 180 and 280 models). "

[tibimakai]

Re: Insignia NS-LCD32 2007 lines on the right

Thank you.
I'm eyeballing a 179 on craigslist(asking $150), but I'm not sure how do I know if everything it's OK with it?
It would be nice if the person would provide a receipt too.

[retiredcaps]

Re: Insignia NS-LCD32 2007 lines on the right

I'm eyeballing a 179 on craigslist(asking $150), but I'm not sure how do I know if everything it's OK with it?

IMHO, $150 is too much money for a Fluke 179. For $150, you can get an used Fluke 87V on ebay with a bit of patience.

You have to test each function. It helps to take AA batteries, a known resistor value, and a capacitor at minimum. You also have to know how to test the fuses to make sure they are good (details in the ebay guide).

http://reviews.ebay.com/Fluke-Meters...00000007231862

[belamex]

Re: Insignia NS-LCD32 2007 lines on the right

Ok.. I just picked NS LCD32 lcd for repair.. the 1117 2.5 was reading 1.5v and 4.9v. I got one red line down the middle sometimes 2. So, my question is, which 1117 2.5 do i get for a replacement?

There are many 1117 2.5 IC out there. thanks guys!

[budm]

Re: Insignia NS-LCD32 2007 lines on the right

See PDF for SOT.
To be sure, are you talking about the 2.5V SOT or the larger one as shown in my picture?
Pictures will help.
See footprint on the spec sheet to see which one match your regulator body size.

[belamex]

Re: Insignia NS-LCD32 2007 lines on the right

Yes. My 1117 2.5sj is reading 1.5 and not 2.5 So I assume it's bad. The 3.3 tested fine.

So, if you have a specific brand, I would like for you to share it with me.

Otherwise I need to know:
1 Input Max Voltage:
2. Output Voltage
3. Dropout Voltage (Max)
4. Output Current
5.Load Regulation
6. Output Type " Fixed or adjustible?
7. Maximum Operating Temperature

Thanks!

[belamex]

Re: Insignia NS-LCD32 2007 lines on the right

Question.. on both of my 1117 2.5 and 3.3, the middle prong is shorter than the outer 2. And I notice that there are 1117 with all 3 prongs the same size. I'm very confused on which one to get.