Frequent Failure Of IGBT In IMPEX OMEGA H5
I am giving below the following link to read my previous article on the same Induction Cooker:
Power Flickering Caused IGBT Failure In IMPEX OMEGA H-5 Induction Cooker | Electronics Repair And Technology News (jestineyong.com) (12th January, 2021)
The cooker had an IGBT failure on 22nd December, 2020. It failed again on 7th June, 2021. This time, therefore, I repeated my work of lifting one leg of all the resistors and checked the value.
I did not find any variations. I removed the transistors and checked and did not find anything wrong with it. Anyhow, as I did not want to replace the resistors and transistors blindly like in many other cases I did, after having learnt a lesson as mentioned by me in yet another Induction Cooker repair article, I removed the fixed caps and checked. Then I found that the values of these were shockingly out. I am giving only two snaps of such cases found. Almost all the Fixed Caps were out:
I replaced all the fixed capacitors with more accurate Polyester capacitors.
Then I applied the power before replacing the IGBT, and checked the voltages of 78L05, 18V Zener and found these to be normal, fan was rotating and the controls were also working fine.
So, ventured to replace the IGBT. Connected the coil and just kept the top for placement of vessel and tried. It worked well.
So, assembled it back and took it to kitchen, when my wife tried and found it to be working very well. What caused IGBT failure? Was it due to these Fixed Capacitors?
Or was it due to power fluctuations? Well, I have no idea! I have done what best was possible that could fix the device. Let us keep our fingers crossed!
(One electrolytic cap you see was removed from the panel. Looks like I had overlooked replacing this last time. )
Satisfaction, of-course, was waiting for its turn to jump into the collection bag!
This article was prepared for you by Parasuraman Subramanian from India. He is 72 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.
Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.
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!
You may check on his previous article on Resistor Found Burnt In SMPS
(62)Dislikes
(0)
11 Comments
Leave a Reply
Albert van Bemmelen
July 26, 2021 at 1:26 pm
I guess since even high electrostatic voltages can destroy many semiconductors it also can happen to the thin foils in e-caps and other caps.
Recently I noticed what even connecting only the red wire plus pole of an smps 0...30V 10Amps power supply (model Wanptek KPS3010D) can do. I just connected it to LEDs in a defect led lightbulb without the bulb stepdown regulator board. It already lit up some of the leds. Just while holding the aluminium bulb in my hand and connecting only the red wire on the anode side of the leds. And even without using the black min pole wire of the regulated power supply! Which with this low current and no real closed circuit was something that was not expected to happen!
Imoudu
July 27, 2021 at 12:04 am
Good detecting repair!!One of fix caps measure 108n, is it abnormal too? Again I observed number of fix caps after repair is less than before repair on the board.why?
Parasuraman S
July 27, 2021 at 4:35 am
This is news to me. I am also amazed to hear this! Many thanks for your comments and sharing of your experience.
Waleed Rishmawi
July 26, 2021 at 7:26 pm
What is the IGBT part number?
Parasuraman S
July 27, 2021 at 4:50 am
I have used FGA25S-125P. The picture of old IGBT, which failed is there in the article at the last. Many thanks for your comments!
Waleed Rishmawi
July 27, 2021 at 1:54 pm
the picture is out of focus I could not see the part number..thanks though
Waleed Rishmawi
July 27, 2021 at 1:56 pm
yea, I was looking to the first photo of the article..my apologies
ivan1
July 28, 2021 at 10:40 am
Hola Recuerdo hace 35 años en nuestros proyectos de amplificadores de audio eliminábamos ruidos de fuente usando 0.1 mf ,eso solo para limpiar las frecuencias de audio, me imagino al interior de la cocina de inducción de producirse mucho ruido por radiofrecuencia ,que probablemente altera las polarizaciones y desencadena el deterioro del IGBT
================================================
Hello I remember 35 years ago in our audio amplifier projects we eliminated source noise using 0.1 mf, that just to clean the audio frequencies, I imagine a lot of radio frequency noise being produced inside the induction cooker, which probably alters the polarizations and triggers the deterioration of the IGBT
Parasuraman S
July 30, 2021 at 12:24 pm
Many thanks for your comments and input!
Yogesh Panchal
July 28, 2021 at 5:07 pm
Good Repair! Sir
Parasuraman S
July 30, 2021 at 12:24 pm
Many thanks!