Comments on: How To Test Adjustable Precision Shunt Regulator TL431

By: Ulises Aguilar

Ulises Aguilar — Fri, 03 Jul 2020 04:11:11 +0000

Ok good Sir will ordering a Book take care

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By: Jestine Yong

Jestine Yong — Wed, 01 Jul 2020 08:21:15 +0000

In reply to Ulises Aguilar.

Hi Ulises,

I'm fine thanks.

Jestine

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By: Ulises Aguilar

Ulises Aguilar — Wed, 01 Jul 2020 03:25:09 +0000

good after noon Mr yong, hope every one around You are OK , Take care

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By: Endale

Endale — Sat, 06 Jan 2018 15:37:59 +0000

In reply to Dan Metzger.

I have a supermax mini receiver but it´s power light is continue sly or about 5-6 hours blinking, after that turning on and when the power line disconnect for a few miniute it blinks, there is Tl431A transistor inside the power supply , i think the problem is this transister. BC547 ior BC1815 is preferable to replace it, if i didn´find Tl431A help me!

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By: Jestine Yong

Jestine Yong — Mon, 17 Apr 2017 01:01:42 +0000

In reply to Benson.

Hi Benson,

From experience, the best is still direct replace the IC and retest. This is an IC thus it is not 100% accurate to check it with analogue or digital multimeters.

Jestine

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By: Benson

Benson — Thu, 13 Apr 2017 02:25:59 +0000

In reply to admin.

hi Jestine im using a fluke 101 digital multimeter how to test that tl431a

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By: Jestine Yong

Jestine Yong — Tue, 13 Sep 2016 01:57:46 +0000

In reply to Dan Metzger.

Hi Dan,

You are welcome.

Jestine

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By: Dan Metzger

Dan Metzger — Mon, 12 Sep 2016 15:59:05 +0000

Worked in my case! I had two identical TVs that were lightning damaged. This test showed me which of the two shunt regulators would possibly work. I used his method of testing the MOSFETs as well. I repaired one TV with parts from the other. Free TV! I can fix the other one for just a few bucks worth of parts.
Thanks Mr. Yong!

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By: Jestine Yong

Jestine Yong — Sun, 08 Jul 2012 21:26:58 +0000

In reply to loon.

HI LOON,

This is an IC and you need to get back the same part number. If you can't get AP431 then try TL431 or S431. I can't guarantee if both numbers can work 100% or not because in some power supply design, it has to use back the same part number which is the AP431.

Jestine

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By: loon

loon — Sat, 07 Jul 2012 21:30:59 +0000

Hi Jestine
Suspected AP431 in acer power board shorted. There is reading when black probe at pin 3 and red probe at pin 1 (intermittent). Any suggestion for equivalent?

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