Comments on: Not Common To See Dual Super Barrier Rectifier Breakdown When Under Load

By: Francis Fernandes, Mumbai, India

Francis Fernandes, Mumbai, India — Fri, 17 Jun 2016 13:30:46 +0000

In reply to Kybosh.

Mr Bandara,
Great work. I wonder if you could comment on a similar problem I had with the SMPS power supply of a DVD player. There is a 8 pin DIL ic which I think is the oscillator (no.4SY103) which I feel is the problem as the set is dead and there is no output 12volts. I need to know the data of this IC but could not find it on the net. If you could throw some light I would be grateful.

Likes(0)Dislikes(0)

By: sylvester

sylvester — Tue, 07 Jun 2016 11:12:04 +0000

Did you try testing with an analoug meter set to x-10, since its only a 12v power supply?

Likes(0)Dislikes(0)

By: justice cele

justice cele — Mon, 06 Jun 2016 13:26:00 +0000

Suranga great job thanks for sharing such vital knowledge.

Likes(1)Dislikes(0)

By: Robert Calk

Robert Calk — Fri, 03 Jun 2016 22:05:18 +0000

In reply to Chris.

Hi Chris,
That's why Mr. Yong recommends checking the diodes with an analog VOM that has the 10K, which includes the 9V battery. The 9V battery plus the 2 AA's will have about 12V to check with on the 10K setting. I don't even waste my time checking them with a DMM.

Likes(1)Dislikes(0)

By: Yogesh Panchal

Yogesh Panchal — Fri, 03 Jun 2016 08:29:34 +0000

Suranga,

What lead you towards this diode failure doubt; are surrounding voltages??.

Likes(0)Dislikes(0)

By: Chris

Chris — Thu, 02 Jun 2016 22:22:15 +0000

Thank's for the interesting article.
In the past of time, I repaired a led brake light on a VW Golf 5. They have some load's in the circuit because the car ECU will alarm a bad bulb if the load is not connected but only the led's.
So, there was some diodes too. The behavior was sometime working brake light and some time not working. I changed and tested all the stuff and the diodes was good on the multi meter. I decide to change the diode's. BanG! the brake light is still working, after 2 years or so...
When I tested the diode under load, she failed. The diode was shorted, without a load she was fine.
I never figured out why the diode had that behavior but it was so.
Thanks for sharing, and keep up with the interesting articles.

Likes(1)Dislikes(0)

By: skwong

skwong — Thu, 02 Jun 2016 10:43:17 +0000

From my experience SMPS power supply has to be tested with load. Normally, I use a bulb rating close to the measured voltage.

Likes(0)Dislikes(0)

By: suranga bandara, Suranga Electronics

suranga bandara, Suranga Electronics — Wed, 01 Jun 2016 11:47:29 +0000

Hi All my Friend,
Thanks so much for your feedback.

Likes(0)Dislikes(0)

By: albert van bemmelen

albert van bemmelen — Tue, 31 May 2016 21:43:59 +0000

Thank you Suranga! This shows that it is so much harder to repair something that behaves erratic than something that doesn't work at all!

Likes(2)Dislikes(0)

By: Henrique Jorge Guimarães Ulbrich

Henrique Jorge Guimarães Ulbrich — Tue, 31 May 2016 16:45:10 +0000

Great, Suranga. I'd never found such an interesting problem yet. Every day is a day to learn something more. Thanks for the share.

Likes(1)Dislikes(0)