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Identify this part please

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notallbad

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The black round component marked with .220.
I originally thought that it is a resistor but I do not believe it is, then I thought perhaps a cap but have never seen one like this before so am now beginning to believe that it is an inductor.
Would someone please confirm what it is and what the markings indicate.

The board is an LCD TV T-Con board, not able to find a schematic for the board.

Thank-you.

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Yes, that looks like an inductor to me. It's either .22uH or .22mH. I can't remember if those values are shown in uH or mH. I would guess it's 220uH, which is the same as 0.22mH.
 
Yes, that looks like an inductor to me. It's either .22uH or .22mH. I can't remember if those values are shown in uH or mH. I would guess it's 220uH, which is the same as 0.22mH.

Thanks. I guess theres no way of measuring that with just a DMM if I were to remove it from circuit.
There appears to be a high pitched buzz coming from the bottom one in the picture, what are the symptoms or a way of testing of a suspect inductor?

I'm guessing it may also not actually be the inductor at fault but possibly due to the signal/voltage line that is at a higher frequency than it should be causing it to be self-resonant.
 
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Definitely an inductor, ferro ceramic surface mount, it is almost certainly not damaged. Inductors are pretty indestructible *UNLESS* you physically break them. It will test short with a DMM if it's good, but also for many other reasons. You really an inductance meter to test them fully.

It probably is 220μH, *IF* the markings on the top are actually the parts value, which is often times not actually the case. In any case, they are almost certainly the inductors for a power supply stage, which means their value is not too critical. The black diodes right next to them and the capacitors C78 and C79 and the Texas instruments TPS56* series IC are all pretty dead giveaways that they are for the power conversion. When the board is plugged in and working, you will probably measure one of the standard logic level voltages off of those two caps.

There appears to be a high pitched buzz coming from the bottom one in the picture, what are the symptoms or a way of testing of a suspect inductor?

A high pitched buzz can mean a lot of things, but usually means that the power converter is overloaded, which means that there is a short somewhere. Could be a capacitor blew up, could be that one of the logic chips went bad, could be a solder blob shorting something, could be something in the back light drawing too much power. Anything that is getting excessively hot is a good suspect.
 
Thanks for your help.
I would just go ahead and buy a replacement board but I have not yet proved that this board is faulty and the root to all my TV problems.
 
Thanks for your help.
No problem


I would just go ahead and buy a replacement board but I have not yet proved that this board is faulty and the root to all my TV problems.
The average asking price for a used, presumably working board is worth it just as a way to test things IMO. But I understand where you're coming from. I don't like spending any money at all, I'm too poor.

Your problems are almost certainly power circuitry related. That noise is a dead giveaway of an SMPS's failure to operate properly. Either a power supply, or power supply section of a board is dead. Or something that draws power from one of those power supplies is drawing much more than it is supposed to. Also, the horse can come before the carriage with these things. A part can blow up, draw too much power, and then the regulator stops working do to being run way overloaded.
 
TPS65160 - BIAS Power Supply

Pins
1 1.14v
2 0.49v
3 14.76v
4 11.53v
5 11.53v
6 0.033 (with meter set on 200m DC range)
7 0.033 (with meter set on 200m DC range)
8 14.76v
9 3v
10 6.38v
11 11.73v
12 0.032 (with meter set on 200m DC range)
13 0.83 (with meter set on 200m DC range)
14 1.2v
15 1.2v
16 5.7v
17 10.78v
18 3.27v
19 0
20 11.62v
21 11.62v
22 11.62v
23 0.033 (with meter set on 200m DC range)
24 1.2v
25 3.2v
26 3.19v
27 0.49 (with meter set on 200m DC range)
28 1.8v

From what I can make out things appear as they should on this I.C.

The main cause of concern is throwing money into the TV to find that the fault lies with the display panel itself, which as we all know is the most expensive part of a tv set and usually irrepairable.
 
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Hummmm... Measuring just the voltages on the pins is not going to be very effective at telling us what we need to know. It is far better to understand what the part is supposed to be doing, and then take surgical measurements of just the right points.

You can use the schematic on the front page of the datasheet as a reference to your particular circuit configuration. The IC is for doing a particular thing with a particular set of parts, I don't see any way or reason why the board designer would go too far away from the recommended schematic to do this specific task. So the schematics should be very much the same, as should the resulting voltages.

You want to measure these voltages at the output stages of the power converter, as the chip is intended to make certain voltages for the rest of the circuit. Note that the chip does so outside of it's self, in external parts. These voltages are...

Vin 12-15 volts (pins 8, 4, and 5)
Vs 15~20 volts (This is probably what you are getting on pins 3 and 8 honestly)
VGL -5 volts (follow pin 11 past one cap, and one diode)
VGH 23 Volts (follow pin 10 across one cap, and one diode)
Vlogic 3.3 volts. (this will be one of the two inductors)

If you are getting all those voltages on the outputs, then there is likely nothing wrong with the power conversion on the card at this stage. It also means that whatever is powering this power conversion stage, is probably working too. But this test is not 100% definitive of fool proof. If something is dipping out after a particular voltage is reached, it could work up to that point, hit the limit, shutdown, then restart. And it could be doing this so fast that the DMM still just sees the correct voltages, even though the controllers output voltage is realistically all over the place.

Bottom line, one really needs a scope to figure out these kinds of things. Experience helps too.
 
so some voltages "stick out" to me, those would be the 5.7 (usually this is the raw input to the regulator), 3.3V (one of the common logic voltages, 1.8V (another common logic voltage) and 1.2V (also a common logic voltage). these common voltages are used in a lot of "mixed logic" boards such as T-CON boards and DSP boards, so so far it looks as if these voltages may be ok. you could try dropping a drop of varnish on the noisy coil, let the varnish dry and see if the noise goes away. also, the big culprit when things like that get noisy are electrolytic caps being dried out. the input rail gets switching noise riding on it, and that noise gets transferred to everything else, and makes things like inductors emit an audible chatter.
 
I am fairly sure that the inductors are 22 μH. The value is shown as 220, meaning 22 + 0 noughts. 220 μH would be 221 and 2200 μH would be 222.

The dot is the direction indicator. I know that in most applications the direction of an inductor doesn't matter, but in some cases where there are other inductors nearby, the interaction between the magnetic fields of the various inductors will vary if some inductors are turned round. Anyhow, all inductors like that have a direction indicator.

The inductor is something like https://www.farnell.com/datasheets/70051.pdf

I have designed with that same value, and the one that I have here has around 5 turns per layer, around 3 layers of turns and the wire is around 0.5 mm diameter. If yours has similar windings it will have similar inductance.

On a different Wurth inductor, I had a lot of trouble with the ferrites cracking or the windings shorting out. Without some expensive test equipement, it is nearly impossible to measure the resistance or inductance accurately enough to be sure if the inductor has failed. In my circuit, the output voltage would spike when the input turned on, and the "on" time would be far shorter than normal. It was also quite common to get a high pitched squeaking if the inductor was broken. The DC voltages were normal when the inductor had failed, but at high load currents the voltage dropped, which it didn't with a working inductor.

I was often using an auxiliary output, which came from a few turns of enamelled wire wound around the inductor. The auxiliary output would not work at all when the inductor was faulty.

The dot on the inductor was needed for that as the winding direction for the auxiliary winding depended on where the dot was facing.
 
ok, thanks for your help.
I have a replacement board on its way, though not 100% sure of its working condition, so shall swap it out and see the results.
In the meantime I shall move onto other things.
Shall keep you posted on the outcome.
 
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