DENON AVR 2311- Power Supply Problem Rectified
I got this Denon AVR which could not power up recently. With a hope to apply my troubleshooting techniques learnt from Mr. Jestine’s class,
- I opened up the unit and found that the SMPS board was mounted vertically on the left side. Had a look at the accessible areas of the various boards and found that they are clean without any visible burnt marks, bulging caps etc.
- Without removing the whole SMPS board, I managed to remove and checked only the 2-fuses on the board. It was found that one (T1.6A 250V) of the fuses had been blown. Since I got a spare fuse, replaced the fuse and switched ON the power. Oops! The same fuse was blown again.
- To extend the troubleshooting further, I removed the SMPS board and conducted visual check on the components first. Found that a switcher IC (which could not seen initially due to vertical position of board) TOP258MG was burnt as well. Also, checked all other components one by one and found that 2-diodes (IN 4007) were faulty. Rest of the components were in order
- Replaced all 6 diodes including the 2-faulty ones, the burnt IC and the blown fuse with the new ones. Removal of IC was a bit challenging as there were a few SMD components nearby. Used Kapton tape to protect those SMD components and replaced the IC safely.
- Connected the power supply to the SMPS board alone. Checked the voltage at main filter cap using DMM and found that voltage was in normal range. Good to see that the fuse was not blown any more.
- Connected the SMPS board back into the AVR. Switched ON the power. Great that the power was back.
7.Next step, Checked the video and audio circuitries by connecting it TV and speakers and found all were in order.
Wow!!!. The Denon AVR2311 is working flawlessly. I am so happy that I am able to apply my learning on SMPS repairs from Mr. Jestine’s class.
Thanks much Mr Jestine. You are The Great Guru.
This article was prepared and shared by Raj, an electronics hobbyist from Singapore. He has done Masters in Industrial Safety Engineering and Degree in Mechanical Engineering. Currently, he is working as a Safety Professional in Singapore. Although he is with mechanical background, his hobby is on consumer electronics stuffs especially on home theatre systems, amplifiers and speakers.
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