- How To Repair Toshiba LED TV With No Power SymptomPosted 7 hours ago
- Samsung LED TV Auto Change Channel RepairPosted 3 weeks ago
- How To Repair LED TV Backlight Problem – No PicturePosted 2 months ago
- How To Repair LED TV No Picture- Singer BrandPosted 8 months ago
- LED TV Repair- Cheap Replacement PartsPosted 8 months ago
- Not Common To See Dual Super Barrier Rectifier Breakdown When Under LoadPosted 9 months ago
- How To Solve No Power Problem In Haier LCD LED TV RepairPosted 12 months ago
- Singer 32″ Skyworth LED TV With Dim Display RepairPosted 1 year ago
- 42″ LG LED TV RepairedPosted 1 year ago
- Polytron LED TV RepairedPosted 1 year ago
Not Common To See Dual Super Barrier Rectifier Breakdown When Under Load
The complaint of this LED TV was no power so the first thing I did was to check the output voltage of the power adapter.
It was rated as 12 VDC and when I measured the output jack of the power adapter I got 12.1 volt which mean it was good -see the photo below:
When i checked on the connector of the dc 12 volt supply in the circuit board I was surprised to see the voltage was only 3.6 volt. It suppose to be 12 vdc and not 3.6 volt.
This means the problem can be caused by either the circuit board itself or the power adapter. In order to confirm which section is giving the problem i have used an external 12 vdc to plug on the circuit board-see the photo below:
It shows 12 vdc and I could see that the LED TV screen was working (see below photo). This concluded that the power adapter is the cause of the problem. It also means that the power supply can’t sustain the current draw by the circuit board causing the 12 volt to decrease to 3.6 volt!
Next, I opened the power adapter and see if I can find some bad components in it. The filter capacitors were checked to be good and there were no sign of burn components too. All components were intact.
Even the dual schottky diodes was tested good when checked with my digital multimeter
Below is the Dual Super Barrier Recctifier datasheet:
Since I could not find any bad components in the power supply, I directly replaced the dual super barrier rectifier and retested it again. I was a bit surprised to see the voltage came back to normal again (11.6 volt) and the display appeared-see the photo below. It had never came to my mind that a dual diodes could breakdown when under load.
Conclusion- Sometimes one just has to direct replace a component and retest the set because a component that is breaking down when under load is hard to be detected by a normal meters.
All the best!
This article was prepared for you by Suranga Bandara who owns an Electronics shop in Anuradapura, Sri Lanka.
Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments. If you have electronic repair articles to share with us, please contact us HERE.
P.S- If you enjoyed reading this, click here to subscribe to my blog (free subscription). That way, you’ll never miss a post. You can also forward this website link to your friends and colleagues-thanks!
Note: You may check out his previous repair article in the below link: