Need help identifying 2 components - Acer cell phone Liquid Zest T06

[rddube]

Hello everyone,

I am trying to identify what are these components?

#1 seems to be an inductor, but I get not reading when measuring it. #2 also seems to be an inductor and again no reading when I measure it. You can see a smaller inductor above #2 that has cracked and open.

Any help in identifying these 2 components would be welcome. I am pretty sure #2 is an inductor, but #1 shape is odd, and I am not sure. I also show a microscope view of each component.

Many thanks!

[mon2]

Re: Need help identifying 2 components - Acer cell phone Liquid Zest T06

Yes, # 2 = inductor.

IC is ET5120A = led backlight controller.

http://www.dayasz.com/et5120-promo.html

How are you measuring this inductor?

Remove all power -> meter in resistance mode. One meter probe on one pad, other meter probe on other pad. Should be ~0 ohm resistance - same as shorting the meter probes.

[rddube]

Re: Need help identifying 2 components - Acer cell phone Liquid Zest T06

Thank you Mon2. Yes I measure in resistance mode, and I get open reading. I am also having a lot of trouble removing it with hot air, it seems to have stuck to the board. I'm at 410C and still won't come off - the broken one has come off.

Do I have to replace them with exact same inductors or any inductor of about the same size would do?

Also, any idea what is # 1 ?

[mon2]

Re: Need help identifying 2 components - Acer cell phone Liquid Zest T06

Suggest to place aluminum foil on the top of parts near the area that you do not wish to disturb. Then flux -> blast this part with heat (high as you can go) in tight circles.

The solder will eventually heat up and melt -> use gentle nudges of the tweezers to move this part. Then pluck it.

From the picture, looks to be ok but no issue to remove and test it while it is out of circuit.

The PCB is always a multilayer PCB with heavy copper ground planes which act like a heat sink so the heat you are sending is often absorbed by the PCB and prevents the quick melting of the solder.

Coils can be replaced by many others. First need a proper footprint -> then the inductance (micro henrys) -> then the same or higher current rating.

[rddube]

Re: Need help identifying 2 components - Acer cell phone Liquid Zest T06

Thank you Mon2 for your great advice.

Any idea what component #1 is?

[mon2]

Re: Need help identifying 2 components - Acer cell phone Liquid Zest T06

#1 - also appears to be an inductor / coil. To confirm, review the solder pads and also to which parts are mated with this component.

A switching power supply controller will often have an external inductor like this one. Based on the size, it is not a 'power inductor' which are larger in size to support the higher peak currents.

Share any top side markings of the ICs that are likely connected to this component.

On this note, these parts rare go bad unless they have been damaged by a drop of a screwdriver, etc. in which case the bobbin will break away like you have in the same posted picture, but north of this part.

In the end, this is like an electromagnet where you have many wraps of a magnet wire on the bobbin.

Shielded inductors will be very similar in shape and look as this component but best to confirm with the footprint / pcb pads.

Unshielded inductors will show the magnet wire.

reference (shielded inductors):
https://www.bing.com/images/search?q...HDRSC3&first=1

unshielded inductors:
https://www.bing.com/images/search?q...hacc=0&first=1

[rddube]

Re: Need help identifying 2 components - Acer cell phone Liquid Zest T06

ok, got it! Tested all 3 inductors and all are good, so the problem doesn't lie there.

This phone won't start or charge, so I am looking at the motherboard. If you look at the left of the inductor #2, there is a larger chip which is a Mediatek MT6350V, that when plugged in with battery and charger cable, comes red hot under my thermal camera. I checked all surrounding caps and none are short, so it has to be this chip. It seems to be sealed with a hard glue of some sort. Not sure if I should try and change it? Or maybe try a reflow at 240C ?

Any advice is welcome!