Comments on: Revisit Of Jinxed AMP With Torroid Transformer Failure https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/ Semiconductors, Test Equipments, Circuit Board Troubleshooting, Electronic Repair Courses and Many More! Mon, 24 Aug 2020 03:15:39 +0000 hourly 1 https://wordpress.org/?v=5.4.19 By: Ulises Aguilar pazzan i https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/comment-page-1/#comment-370724 Mon, 24 Aug 2020 03:15:39 +0000 https://jestineyong.com/?p=21605#comment-370724 MR Parasuraman Grate Sir ,grate repair Very ingenious, I like that ,very Good Sir

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]]> By: Parasuraman S https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/comment-page-1/#comment-368382 Tue, 28 Apr 2020 12:04:37 +0000 https://jestineyong.com/?p=21605#comment-368382 In reply to Lynn Blakely.

Yes, very true. Many thanks.

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]]> By: Lynn Blakely https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/comment-page-1/#comment-368360 Sun, 26 Apr 2020 23:16:21 +0000 https://jestineyong.com/?p=21605#comment-368360 Gentlemen: This is a very needed type of instruction, and it shows that experiences like these are not forgotten.We need to be reminded of some of the things that others have learned. Thanks to each one who commented to this inrush current problem. It may also show that the original failure may have been caused by the lack of input surge limiting.

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]]> By: Parasuraman S https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/comment-page-1/#comment-368155 Sat, 18 Apr 2020 05:10:37 +0000 https://jestineyong.com/?p=21605#comment-368155 In reply to Henrique J. G. Ulbrich.

Many thanks for your input. The Amp is reportedly working fine. I shall take care of these inputs for my future troubleshootings.

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]]> By: Parasuraman S https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/comment-page-1/#comment-368153 Sat, 18 Apr 2020 05:09:04 +0000 https://jestineyong.com/?p=21605#comment-368153 In reply to Paris Azis.

Yes. I do understand how difficult and disturbing it is. There is no capacitor in the primary of this Transformer. You are right, the AC Capacitors provided as a noise filter of electromagnetic waves, can cause problems when they develop partial leak. It is better to replace these during our trouble shooting work.

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]]> By: Parasuraman S https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/comment-page-1/#comment-368152 Sat, 18 Apr 2020 05:05:34 +0000 https://jestineyong.com/?p=21605#comment-368152 In reply to Albert van Bemmelen.

Many thanks for your input!

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]]> By: Paris Azis https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/comment-page-1/#comment-368109 Fri, 17 Apr 2020 20:24:49 +0000 https://jestineyong.com/?p=21605#comment-368109 In reply to Parasuraman S.

I hope that time will prove the success of this repair dear Parasuraman.
The last time I had a similar problem, it had driven me crazy... It was a public address amplifier, a high wattage one, used in a multi-floor building. The problem was almost immediate blow of its 20A(!!) fuse in the secondary side, before I could even see that the power was on...And all of that after my repair on one of its push-pull output branches...
To make the long story short, the culprit was merely a 470nF capacitor at the primary side of the output transformer circuit, found completely degraded and due to that very high frequencies were developed all around the power line and then distributed within all the stages of the amplifier destroying repeatedly one of the power output branches, that is, three 2N3035 transistors in parallel (per branch).
I was speechless when I saw these oscillations riding on the power line, because there were no other symptoms like squeals in its output. Everything was seemingly perfect until I saw what was happening using the oscilloscope.
But I was aware that “something was very wrong” with that amplifier, as I was the fourth technician in a raw attempting to repair it. It’s owner had already lost the hope of seeing it alive again...
Anyway, I hope that your case is not a similar one and the countermeasures you took will effectively eliminate the cause of that problem.
I am only worry about it because I know that feeling of encountering the same problem again...

Best Regards!

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]]> By: Henrique J. G. Ulbrich https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/comment-page-1/#comment-368078 Fri, 17 Apr 2020 15:00:09 +0000 https://jestineyong.com/?p=21605#comment-368078 Dear Parasuraman, I agree with Paris Azis. It shall be a NTC, and pursuant to the initial idea, there must be a kind of delay, what the circuit does not show. Another doubt is either if this NTC is original of the input circuit or if it was added by you in this implementation. Anyhow, I realize a merit of this implementation: as the relay operates and so remains, the short-circuit of its contacts remove any voltage on the NTC, keeping it cold to efficiently operate next time.

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]]> By: Parasuraman S https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/comment-page-1/#comment-368075 Fri, 17 Apr 2020 14:31:41 +0000 https://jestineyong.com/?p=21605#comment-368075 In reply to Paris Azis.

Many thanks for sharing a lot of valuable inputs on this service. The circuit is working well and the customer informed me that the AMP is working perfectly. So, that solves the problems!

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]]> By: Parasuraman S https://jestineyong.com/revisit-of-jinxed-amp-with-torroid-transformer-failure/comment-page-1/#comment-368073 Fri, 17 Apr 2020 14:27:45 +0000 https://jestineyong.com/?p=21605#comment-368073 In reply to Waleed Rishmawi.

Many thanks. Yes, he confirmed that it was working very well. At-last!

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