اخبار: BLUE RING TESTER چیست؟

[pese]

ابزاری خوب جهت تست سلامت ترانس ها می باشد.

Today I am going to share one of my troubleshooting experiences with Blue Ring Tester which I have bought from Mr. Jestine Yong. There was a problem with one SMPS which was dead and not showing output voltages. The SMPS was a 12V 120Watt and used as LED power supply.
​

One of my customers came to my office and told me that the SMPS was not working. After testing the SMPS I found the main fuse, bridge rectifier and power FET was shorted. After replacing all the components I used the series light bulb trick and the bulb was brightly lit and this means there was still short circuit in the board.​

I suspected the main filter capacitor but after replacement the problem was still the same. My next moved was to check on the SMPS transformer primary winding. The Blue Ring Tester showed full LEDs and this means the SMPS transformer primary winding was good. When I checked on the secondary winding I found that it was open circuited causing the bulb to light up.​

Here is how I have checked the transformer:​

I removed the bad Switch Mode Power Transformer (SMPT) and compared with a good one. I checked it the way as mentioned in the Switch Mode Power Supply Ebook by Mr. Jestine Yong. First, I checked the primary winding of the transformer and found the winding to be good as shown in the below photo (8 full LEDs lighted up).​

​

Then I made a short between pins in secondary winding with Long Nose Plier and there was no effect on LED bar of Blue Ring Tester. Please see the photo below:​

​

Note: A good transformer when shorted the secondary pins, the Blue Ring Tester LEDs should go off or one or two LEDs should be blinking. Please see the photo below:​

​

All the 8 LEDs went off when shorted the secondary pins with a long nose plier​

A replacement with a new SMPT brought the dead power supply to life again.​

​

This article was prepared for you by one of my ERG members. Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.​

By the way if you have any good repair article that you want me to publish in this blog please do contact me HERE.
​

 

[pese]

Tip: If the power FET is good then you can just replace the bridge rectifier diodes and the main fuse and power it on to test the power supply.



After confirmed that the power FET is shorted my next move was to check on the primary winding of the main transformer. It was tested good and showing 8 LEDs on my Blue Ring tester.

blue ring tester check



Note: There is no point to troubleshoot the ATX power supply if you found that the primary winding of the main transformer is shorted. The reason for it –there is no such part for sale. If you did not check on the primary winding first and you concentrate on checking other components, time will be wasted if at the end of the troubleshooting you found that the transformer is indeed shorted. If you check on the primary winding first and confirmed that the primary winding is shorted, you can just pack up the power supply and continue to do other repair job. Time is very important in electronics repairing.

 

[pese]

[h=3]The BLUE Ring Tester[/h]

 

[pese]

[h=1]How To Completely Test LCD Inverter Transformer[/h]

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Home > LCD Monitor Repair > How To Completely Test LCD Inverter Transformer​

[h=1]How To Completely Test LCD Inverter Transformer[/h]

By admin on January 5, 2015​

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The function of LCD TV/Monitor high voltage transformer is to produce high AC voltage (from few hundreds to more than a thousand AC volt) to light up the CCFL backlight. If this transformer have problem it will cause the LCD screen to light up for a second and then shutdown or to have dim display problem. Basically the high voltage transformer can have four types of problems such as:​

1) Open circuit especially the secondary winding​

2) Shorted in secondary winding​

3) Increase in resistance in secondary winding​

4) Breakdown when under load​

Note: The primary winding seems to be quite robust and rarely give problem.​

​

​

How are we going to know if the high voltage transformer have problem or not? The answer for it is to use the right test equipment to check it.​

1) Open circuit especially the secondary winding​

All secondary winding should have resistance between several hundred to several thousand Ohms. Just place your Ohmmeter at the secondary pins and you should get the Ohm reading. If you did not get any reading means the secondary winding already open circuit.​

​

An open secondary winding can cause display to shutdown in few seconds or dim display depending on how many transformer is used in the circuit design. This means if the circuit design is only using one high voltage transformer to support one backlight and if the secondary winding is open circuit then there will be dim display problem. If it is uses two transformers and one of the transformers secondary winding has an open circuit then the symptom would be display shutting down in a second or two.​

​

Note: Primary winding also has resistance and the Ohm value is very small.​

​

2) Shorted in secondary winding​

If there is a shorted secondary winding, a normal multimeter would not be able to detect it. You need to use a coil tester such as the Blue Ring Tester. For a much bigger high voltage transformer you can expect at least 4 LEDs will light up. If the tester did not light up at all means the secondary winding is shorted.​

​

Note: You also have to take note that a slighlty small high voltage transformer secondary winding may not be able to read by the Blue Ring Tester. The tester could read up until 2 or 3 LED lights only. However, if the LCD inverter has more than one high voltage transformer then it would be easy to judge the result (comparison test).​

You can use the comparison method on the two transformers and locate the faulty one​

​

Some designs only have one transformer but you still can compare the winding because the above transformer have one primary winding and two secondary windings​

​

3) Increase in resistance in secondary winding​

You will be surprised that the resistance in secondary can increase when there is a problem. It is due to a prolong increasing in temperature in the high voltage transformer.​

​

If you notice a vast different in Ohm’s reading (usually higher resistance) meaning to say the transformer is bad.​

I have found many LCD high voltage transformers problem are due to increase in resistance in secondary winding in one of the transformers.​

Note: A slight different in resistance reading is acceptable when checking on two similar transformers.​

Most of the LCD inverter boards have more than one high voltage transformer thus it would be easy to compare the secondary winding and find out the problematic one.​

4) Breakdown when under load​

Although is rare, I did came across one before. On top of the secondary winding I saw a very tiny spark while the LCD Monitor inverter was working. It caused intermittent display shutdown. When I took out the transformer and test it, it seems to be working fine. A replacement brought the LCD Monitor back to life again.​

​

The question now, what if the transformer is fully covered and you can’t see the spark. In this case, it would be a little bit tough to solve it. What you can do is to make sure there is no bad components in the inverter circuit and all the CCFL lights are good (you can test them with a CCFL backlight tester). Check the transformer for good resistance reading and make sure no shorted reading (test it with a Blue Ring Tester). This means if you have checked all the parts and the LCD Monitor or the TV still have intermittent display shutdown problem then there is a possibility one of the high voltage transformers could be breaking down when under load.​

Conclusion- I hope the above article will help you in solving LCD problem that is related to the inverter high voltage transformer. If you have additional method in testing/checking of the high voltage transformer please do leave your comment below-thanks.
​

 

[reza_476]

باسلام

در این تاپیک در آدرس زیر من در مورد بلو رینگ تستر یا میدان سنج، کلی توضیحات و نحوه عملکرد و یک نمونه ساخته شده را به زبان فارسی توضیح دادم:
[hide]

http://www.irantk.ir/irantk53130/
​

[/hide]

 

[reza_476]

باسلام

دستگاه فوق قابلیت تست فت و ماسفت را ندارد.

 

[pese]

باسلام

دستگاه فوق قابلیت تست فت و ماسفت را ندارد.

این دستگاه برای تست ترانس ها تا چه اندازه قابلیت اطمینان را دارد. چون ظرفیت ها و اهم و هانری را نشان نمی ده .اساس کار این دستگاه چی هست..
یک مداری هست در انجمن که برای تست فت ها و موس فت ها ساخته می شه و یک سری تست که با مولتی متر هم می شه انجام داد ولی من خودم در بعضی مواقع با این تست ها جواب نگرفتم ( البته فقط بعضی مواقع خیلی خیلی کم با این نوع تست ها جواب نگرفتم) دنبال یم روش تست هستم که 100 درصد قطعی باشه.

تست ترانس ها هم با مولتی متر انجام می دهم ولی اساس تست ترانس میزان اهم و هانری پایه ها که باید بدست بیاوریم و پیدا کردن دیتاشیت ترانس ها واقعا مشکل هست.
آیا این دستگاه جواب 100 درصد قطعی می ده

 

[reza_476]

باسلام

مهمترین کار و ارزشمندی که این دستگاه میدان سنج انجام میدهد:

[hide]
سیم پیچهای اولیه ترانسهای سوئیچینگ که تعداد دورشان زیاد است اگر در در وسط سیم پیچ 5 ای شش دور اتصال کوتاه باشد با اهمتر نمیشود آنرا تست کرد زیرا اهم آن آنقدر کم است که نشان نمیدهد لذا ترانس عملکرد صحیحی نخواهد داست ولی این میدان سنج عیب قابلیت کشف اینگونه عیوب را نیز دارا میباشد که طریقه استفاده از آنرا در تاپیکهای قبلی تشریح کردم
[/hide]

 

[reza_476]

باسلام

تستر انواع نیمه هادی ها که دوست عزیزمان آقای مهندس رسولی زحمت ساخت آنرا میکشند با این دستگاه فرق میکند آن انواع ترانزیستورهای فت و ماسفت و .... تست میکند که در سایتمان همان فروشگاه صبا است

 

[علی تحیری 1]

ابزاری خوب جهت تست سلامت ترانس ها می باشد.

Today I am going to share one of my troubleshooting experiences with Blue Ring Tester which I have bought from Mr. Jestine Yong. There was a problem with one SMPS which was dead and not showing output voltages. The SMPS was a 12V 120Watt and used as LED power supply.
​

One of my customers came to my office and told me that the SMPS was not working. After testing the SMPS I found the main fuse, bridge rectifier and power FET was shorted. After replacing all the components I used the series light bulb trick and the bulb was brightly lit and this means there was still short circuit in the board.​

I suspected the main filter capacitor but after replacement the problem was still the same. My next moved was to check on the SMPS transformer primary winding. The Blue Ring Tester showed full LEDs and this means the SMPS transformer primary winding was good. When I checked on the secondary winding I found that it was open circuited causing the bulb to light up.​

Here is how I have checked the transformer:​

I removed the bad Switch Mode Power Transformer (SMPT) and compared with a good one. I checked it the way as mentioned in the Switch Mode Power Supply Ebook by Mr. Jestine Yong. First, I checked the primary winding of the transformer and found the winding to be good as shown in the below photo (8 full LEDs lighted up).​

​

Then I made a short between pins in secondary winding with Long Nose Plier and there was no effect on LED bar of Blue Ring Tester. Please see the photo below:​

​

Note: A good transformer when shorted the secondary pins, the Blue Ring Tester LEDs should go off or one or two LEDs should be blinking. Please see the photo below:​

​

All the 8 LEDs went off when shorted the secondary pins with a long nose plier​

A replacement with a new SMPT brought the dead power supply to life again.​

​

This article was prepared for you by one of my ERG members. Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.​

By the way if you have any good repair article that you want me to publish in this blog please do contact me HERE.
​

با سلام خدمت شما کاربر گرامی:
بعضی از موارد تست با این دستگاه که با اتصال کوتاه کردن با یک دم باریک (LONG NOSE) انجام می شود درست مثل تست یک منبع تغذیه سویچینگ یا پاور کامپیوتر است که در هنگام تست اتصال کوتاه (SHORT CIRCUIT) بلافاصله کل ولتاژ ها قطع می شود. چون دارای مدار محافظت در برابر اتصال کوتاه می باشند.