Bad Viper 12 A Power IC In Induction Cooker
The induction cooker came in for repair with the complaint of no power. From my experience, the complaint of no power with induction cooker was very common. You can take a look at the previous post here.
As usual, the first thing to do before start to repair the power board, one has to remove the cover. Next, do a visual inspection to find out any burnt components and loosen cables at the connectors. If all checked to be good then the next step is to check on the power supply output dc voltages. From the test, there were no output voltages and this confirmed the power supply itself have problem.
When I closely looked into the power supply board, I actually saw a 2 watt resistor where the outer layer was cracked.
I furthered test on the power IC VCC pin and the hot ground and found that indeed it was shorted (very low ohm).
I checked on all the components power supply side and all the other components seems to be in good condition. My conclusion was that only the power IC and the resistor that were having problem.
I then installed new components (a resistor and Viper12A IC) into the power supply board and perform a bulb test to make sure there was no longer short circuit in the power supply once the AC is supplied. And it had proven no more short circuit because the bulb did not light up with full brightness.
If the bulb have a constant light, then I need to carry on checking the power supply. Who knows the power transformer can have short circuit when full power is applied.
I took out the 40 watt bulb and installed a new fuse and powered it On. Look at the photo below where the problem was solved. It was an easy job but you need to know that in order to be able to troubleshoot electronics equipment, one has to be good in checking or testing components. If you have not got Jestine’ ebook, I can recommend that you get it here.
This article was prepared for you by Suranga Bandara who owns an Electronics repair shop in Anuradapura, Sri Lanka.
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Albert van Bemmelen
December 26, 2019 at 10:01 pm
Good job in finding the only 2 circuit culprits Suranga! These Low power offline dedicated current switched-mode primary power switchers with build in high voltage Mosfet are also used in other kitchen appliances like Washing machines and Tumble dryers. And there they also stop working too often caused by a shorted power switcher IC and its burned open serie 'safety' resistor. They are mostly of the LNK type of IC family.
Francisco Rica
December 27, 2019 at 3:54 am
Hu Suranga.
Interesting repair! About the Power IC test of Vcc pin to hot ground, you obtained 48 ohm. And this is shorted. What are the typical resistance values for a good Power IC?
Robert Calk Jr.
December 27, 2019 at 6:25 am
Good job, Suranga!
Parasuraman S
December 27, 2019 at 3:32 pm
Well done! Useful share!
R H Pillai
December 27, 2019 at 4:18 pm
Electricity bill is very low ! 🙂
Yogesh Panchal
December 27, 2019 at 5:59 pm
Good Repair! suranga
ICEON
July 30, 2020 at 6:52 am
hi I find your report useful. But there is this cooker that was brought to me I figured out the viper 12A IC and the 22ohms resistor was bad but after replacing it wont power on as the display will not work. I also noticed that the IC connecting to the display board is reading continuity between positive and negative how do i get the ic number as the only inscription on it is 00gp820
Giant
August 11, 2021 at 1:06 pm
Hi Suranga,
I have similar problem with my induction cooker but i can't find relevant resistor. Do you remember resistance of that 2watt resistor?