capacitor with no esr value

[tom66]

Re: capacitor with no esr value

The attachments you have linked to aren't working...

[1supertech]

Re: capacitor with no esr value

Other pic of mainboard may be to small
I think this will do

[tom66]

Re: capacitor with no esr value

Is there anything on the back side of the board? Any LDOs like in the picture?

http://img.diytrade.com/cdimg/108715..._LM1117_1A.jpg

[1supertech]

Re: capacitor with no esr value

Nope

[tom66]

Re: capacitor with no esr value

I can see one next to the two black caps labelled NP3. There may be others, I can't see any though. Test all the pins of NP3, relative to the metal case.

[1supertech]

Re: capacitor with no esr value

Yes I do see it and what do you mean by test relative to the metal case

[tom66]

Re: capacitor with no esr value

Yes I do see it and what do you mean by test relative to the metal case

Meter on volts DC (20V), black probe in COM slot on meter and in a spare screw hole on TV (or any hole on the metal frame), red probe in volts/ohm and test each pin. Middle pin is the same as the fat tab, no need to test the fat tab. Report the pins 1, 2 and 3 (labelled arbitrarily, suggest left to right and that you keep it the same for each device.) Also include the part number on the device, for example AMS1117-18.

[1supertech]

Re: capacitor with no esr value

Thank you Tom

[1supertech]

Re: capacitor with no esr value

Meter on volts DC (20V), black probe in COM slot on meter and in a spare screw hole on TV (or any hole on the metal frame), red probe in volts/ohm and test each pin. Middle pin is the same as the fat tab, no need to test the fat tab. Report the pins 1, 2 and 3 (labelled arbitrarily, suggest left to right and that you keep it the same for each device.) Also include the part number on the device, for example AMS1117-18.

From left to right
1.3

3.303

05.04

part # EHI6A
715F83

[budm]

Re: capacitor with no esr value

I looked at the NP3, looks like Adjustable regulator (you can see two network resistors on pin 1 & Gnd and pin1 & pin2. If that is the case the output should be 1.3 +1.25Vref = 2.55V output at pin 2 ( if we know the value of the two resistors then we can calculate the output voltage). Input pin 3 is 5V as printed on the board.
On the bottom side around top left corner, you can also see Adjustable Vreg VA21.

[tom66]

Re: capacitor with no esr value

The best way to check an adjustable regulator is the Vout to ADJ pin should measure 1.25V approximately.

[1supertech]

Re: capacitor with no esr value

You guy's are lossing me LOL

[budm]

Re: capacitor with no esr value

I have a feeling you have bad regulator, the output is too high. 1.25V ref is part of the internal circuits of the Regulator.

[1supertech]

Re: capacitor with no esr value

so is this what was causing the short between power supply annd mainboard?

So I guess I need to buy another part form a digikey? # EHI6A 715F83

[1supertech]

Re: capacitor with no esr value

I am trying to find this part # LDO regulator the # on chip are EH16A 715F83 cannot find it
help would be appriciated

[Mr Bill]

Re: capacitor with no esr value

I am trying to find this part # LDO regulator the # on chip are EH16A 715F83 cannot find it
help would be appriciated

Its a LDO regulator. Search this pdf and it'll show a table with your part number listed as "marking ID". The table is on page 4. Hope this helps you.

[budm]

Re: capacitor with no esr value

You can get the Adjustable LDO 1117 series from Digikey.

[1supertech]

Re: capacitor with no esr value

I just received my LDO regulators; I guess the best way to remove and install regulators is a hot air station with liquid flux and solder paste ?

[tom66]

Re: capacitor with no esr value

That works fine for me - you can also desolder them by applying a large glob of solder over all the pins, and then heating the glob with a soldering iron while slowly pushing the regulator. It will come off fairly quickly that way.

[1supertech]

Re: capacitor with no esr value

That works fine for me - you can also desolder them by applying a large glob of solder over all the pins, and then heating the glob with a soldering iron while slowly pushing the regulator. It will come off fairly quickly that way.

I just tried removing a regulator of of a dead motherboard to practice, it worked ok with the solder that I have, but I think I will order some chip quick
and try it that way.

Thanks tom66