Comments on: Dry Solder Caused Lead Of EMI Filter Coil Getting Charred In LG DVD Player Model DV692

By: Parasuraman S

Parasuraman S — Mon, 26 May 2025 06:09:29 +0000

In reply to Muykit.

Thanks for your elaborate and valuable comments, dear Muykit! The primary circuit depends upon the expected load and if these are minimal, the EMI circuits are excluded. But there would be adequate compensation in the main board for sure, because noise is an important factor in power supply circuits.

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By: Parasuraman S

Parasuraman S — Mon, 26 May 2025 06:05:54 +0000

In reply to Imoudu.

Many thanks, dear Imoudu!

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By: Muykit

Muykit — Sun, 25 May 2025 22:57:52 +0000

Thanks Engineer Parasuraman. Luckily. the EMI coil survived being 'shorted', though they rarely get destroyed anyway, especially the twin-coil ones that are often connected in parallel. I guess the rectifier diodes, a ceramic capacitor, to some extend the main input capacitor, and probably the main fuse too, were spared because the EMI coil never got burned (shorted) while remaining properly connected to the power cicuit board. In my minds eye, the coil hard a poor connection or dry joint in the power circuit that created a restance high enough to minimize current flow that would have otherwise caused extensive damage to the power input components including but not limited to the power fuse. 2. I often wonder why small smps circuits, for example those of TV external adapters or TV set top boxes have no EMI coils in their input power supply yet they work just well enough without much harm with only the rectifier diodes taking care of unecessary reverse current flow ?

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By: Mark J

Mark J — Sun, 25 May 2025 19:14:04 +0000

In reply to Parasuraman S.

You are welcome. I am still aspiring to be as good of a repair technician as you.

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By: Imoudu

Imoudu — Sun, 25 May 2025 15:57:53 +0000

Such filter coil is hard to buy except you get replacement from scrap,but you manage to mend it,good job sir.

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By: Parasuraman S

Parasuraman S — Sun, 25 May 2025 02:24:14 +0000

In reply to Mark J.

Many thanks for your encouraging comments, dear Mark!

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By: Mark J

Mark J — Sat, 24 May 2025 18:40:58 +0000

Parasuraman thank you for sharing your knowledge and experience. Good job on the repair.

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By: Parasuraman S

Parasuraman S — Sat, 24 May 2025 15:54:28 +0000

In reply to Humberto.

Yes, dear Humberto and thanks!

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By: Parasuraman S

Parasuraman S — Sat, 24 May 2025 15:53:56 +0000

In reply to Humberto.

Yes, true!

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By: Humberto

Humberto — Sat, 24 May 2025 12:40:50 +0000

Another electronic device saved from the dump

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