Comments on: 1.8V Voltage Regulator IC Problem In LED Monitor

By: Jestine Yong

Jestine Yong — Mon, 06 Mar 2023 08:54:33 +0000

In reply to Fed.

Hi Fed,

1- When you say: “I measure between THE GROUND and the IC output (pin2)…” Do you mean, the ground pin of the 1117 1.8 OR do you mean, a ground spot/point somewhere on the circuit board?

Both are the same coz both grounds are cold grounds (metal casing).

2- And what do you mean, when you say: “It gave a high and a low reading which was good…” HOW are you getting two readings, what did you do exactly? - please clarify the procedure, in detail.

When the VCC line is shorted to ground you will get two similar low ohms readings (either way) using Analogue meter set to x1 Ohm. If the VCC line is not shorted you will get a higher and a lower Ohms reading when you reverse the probes.

Jestine

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By: Fed

Fed — Wed, 22 Feb 2023 01:43:35 +0000

Hello,
This was a great lesson, and quite rare too. Nobody on the internet, has ever explained how to test an SMD voltage regulator IN-CIRCUIT - so, thank you very much!
But I have two questions:

1- When you say: “I measure between THE GROUND and the IC output (pin2)…” Do you mean, the ground pin of the 1117 1.8 OR do you mean, a ground spot/point somewhere on the circuit board?

2- And what do you mean, when you say: “It gave a high and a low reading which was good…” HOW are you getting two readings, what did you do exactly? - please clarify the procedure, in detail.

Thank you kindly

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By: Jestine Yong

Jestine Yong — Thu, 21 Sep 2017 03:09:38 +0000

In reply to diwa.

HI Diwa,

Without hands on assessment I would be really guessing on what might be wrong. Unstable voltage problem can be caused by many factors. I suggest that you check the output filter capacitors with esr meter.

Jestine

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By: diwa

diwa — Mon, 18 Sep 2017 14:05:34 +0000

sir,
my acer ph660 monitor voltage is unstable even in direct line without vga attached the screen shakes and rolls, could you suggest me is it the capacitor problem? i m in trance.

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By: Feroz tejani

Feroz tejani — Wed, 06 Sep 2017 18:04:07 +0000

Sir can you please explain the different voltages of an lcd/led tv motherbord like 3.3v ,1.8v etc and to which sections these voltages are used for

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By: Abdul Kader

Abdul Kader — Tue, 17 Nov 2015 10:41:50 +0000

Thank u boss

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By: Jestine Yong

Jestine Yong — Thu, 21 May 2015 23:41:37 +0000

In reply to DIPTEEKANTA MAHAPATRA.

HI Depteekanta,

Vertical line is the problem of horizontal section. Try check the horizontal yoke coil area for dry joints and make sure the horizontal yoke coil is not open circuit.

Jestine

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By: DIPTEEKANTA MAHAPATRA

DIPTEEKANTA MAHAPATRA — Thu, 21 May 2015 00:18:35 +0000

In reply to Jestine Yong.

dear Jestine yong
in my CRT monitor screen.a vertical line is showing.and no picture will be shown.what's the matter.can you help me to solve this problem.

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By: Jestine Yong

Jestine Yong — Sun, 26 Apr 2015 23:19:32 +0000

In reply to Veyron.

H Veyron,

It means that if the dc output line is shorted there will be two similar readings. If it is normal it will usually have a higher ohm and lower ohm value when you reverse your probe and test. I suggest that you visit this link for more information https://www.jestineyong.com/audio-interface-repaired/

Jestine

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By: Jestine Yong

Jestine Yong — Sun, 26 Apr 2015 23:14:31 +0000

In reply to Aziz.

HI Aziz,

You are welcome.

Jestine

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