Comments on: Electronic Repair Questions/Answers and Testmonials- Part 64 https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/ Semiconductors, Test Equipments, Circuit Board Troubleshooting, Electronic Repair Courses and Many More! Mon, 22 Nov 2010 03:02:54 +0000 hourly 1 https://wordpress.org/?v=5.4.19 By: admin https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/comment-page-1/#comment-7757 Mon, 22 Nov 2010 03:02:54 +0000 https://www.jestineyong.com/?p=3134#comment-7757 HI Hussien,

I have not seen this problem before but you have to make sure that the power supply output is always good and stable. Make sure the filter cap have good ESR value and no dry joints in the h/v oscillator ic and the tuner box pins.

Jestine

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]]> By: Hussein https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/comment-page-1/#comment-7742 Sat, 20 Nov 2010 12:29:44 +0000 https://www.jestineyong.com/?p=3134#comment-7742 hi Jestine,
the picture in my tv is shifted to the right and it turns blue after a while...and if i remove the antenna i see a vertical black line at the left...what could be the cause?...
thanks alot for your help!

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]]> By: admin https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/comment-page-1/#comment-7156 Fri, 08 Oct 2010 01:56:18 +0000 https://www.jestineyong.com/?p=3134#comment-7156 HI Daniel,

Thanks for the suggestion and i have taken note on that. Will let you and the readers know once it is done.

Jestine

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]]> By: admin https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/comment-page-1/#comment-7155 Fri, 08 Oct 2010 01:54:28 +0000 https://www.jestineyong.com/?p=3134#comment-7155 HI Daniel,

May i know what do you mean of your post were cut off? I thought i have given you an answer. Okay email me personally at jestineyong(at)electronicrepairguide.com

Have a good day!

Jestine

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]]> By: Daniel F https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/comment-page-1/#comment-7145 Thu, 07 Oct 2010 05:18:29 +0000 https://www.jestineyong.com/?p=3134#comment-7145 On another note, you should consider implementing an rss feed for your blog.
I'm sure many of us would find it useful.

Danny

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]]> By: Daniel F https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/comment-page-1/#comment-7144 Thu, 07 Oct 2010 05:16:33 +0000 https://www.jestineyong.com/?p=3134#comment-7144 Hi Jestine,

I'm not sure why my posts were cut off?

Anyway, as I was saying, according to the datasheet the audio amp LM4838MTE has a maximum working voltage of 6v and max temperature of

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]]> By: admin https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/comment-page-1/#comment-7102 Tue, 05 Oct 2010 00:11:48 +0000 https://www.jestineyong.com/?p=3134#comment-7102 HI Daniel,

How many volt did you get by measuring the audio ic?

Jestine

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]]> By: admin https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/comment-page-1/#comment-7101 Tue, 05 Oct 2010 00:10:50 +0000 https://www.jestineyong.com/?p=3134#comment-7101 Hi Daniel,

Yes it could be the mainboard fault. If the mainboard is receiving all the good voltages then most probably the mainboard have problem because the power LED and the front panel button function all is related to the mainboard MCU. Yes the audio IC usually runs on 12 volt and it should not be too hot to be touched. Try remove the audio ic and power on to see if the monitor will work or not.

Jestine

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]]> By: Daniel F https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/comment-page-1/#comment-7080 Sun, 03 Oct 2010 23:27:50 +0000 https://www.jestineyong.com/?p=3134#comment-7080 Hi Jestine,

Since my last post I found a better datasheet.
The problem IC is a LM4838MTE which is a Stereo 2W Audio Amplifier.
It's absolute maximum working is 6v and maximum temperature is

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]]> By: Daniel F https://jestineyong.com/electronic-repair-questionsanswers-and-testmonials-part-64/comment-page-1/#comment-7073 Sun, 03 Oct 2010 09:40:35 +0000 https://www.jestineyong.com/?p=3134#comment-7073 Hi Jestine,

I have another problem lcd monitor.
I'm working my way through your ebook lcd monitor repair.

This lcd uses an external power supply which i've tested and is fine, but I've also tried a replacement spare power supply and I have the same problem.

There is partial power to the inverter board but not on all the pins.
The 6 pin connector from the main board to the inverter has 4 pins with 12v but 2 pins have nothing and I suspect that is part of the problem. There is also no leds for power etc lighting up on front panel.

When I checked the voltage on the on/off switch connector pin on the main board it read around 0.4 volt and then shifted to around 0.2 volt when the on/off switch was pressed. So I think the problem is the main board is supplying some, but not all necessary start-up voltages.

The other oddity is that the audio amplifier is getting very hot and you can only touch it for a couple of seconds before it seriously burns.... I know this can't be right!

I read in your ebook that audio amps usually run around 12v, although this does have 12v on the vcc pins, the datasheet for this chip says

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