DENON AVR 2312- Power Supply Problem Rectified
Good Morning,
I got this Denon AVR which could not power up. I applied my troubleshooting techniques learnt from Mr. Jestine’s class in KL.
- Since I have previously rectified the power supply problem in another model Denon 2311, I suspected that the problem in this Denon 2312 could be something similar, like faulty IC TOP258MG and some diodes.
- I opened up the unit and found that the SMPS board is mounted on the left side. Without removing the board, I checked the two fuses ((T1.6A 250V) on the board and both were found to be good.
- The board is not a plug and play type. Desoldering of 5V connector terminals to be done for the removal of the board.
- After desoldering and removing the board, conducted visual checks on the components first and found that the board was clean without any visible burnt marks, bulging caps etc. The IC TOP258MG was intact without any burnt marks.
5. Connected the power supply to the SMPS board alone. Checked the voltage at main filter cap using DMM and found that voltage was abnormal.
6. To continue the troubleshooting further, checked the diodes and other key components and found that 2-diodes (IN 4007) and one resistor (1M ohms) were faulty. Rest of the components were appeared to be in order.
- Replaced 6 diodes including the 2 faulty ones and also, 4 resistors in a row including the faulty one. 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. Checked the voltage at the output terminals and found 5.2V.
- Connected the SMPS board back into the AVR. Switched ON the power. Wow! Great! The power was back.
9. Next step, checked the video and audio circuitries by connecting it to TV and speakers and found all were in good order.
Denon AVR2312 is working flawlessly now. I am so happy that I can continue applying my learnings 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.
P.S- If you enjoyed reading the above article, 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 post in the below links:
https://jestineyong.com/denon-avr-2311-power-supply-problem-rectified/
(89)Dislikes
(0)
15 Comments
Leave a Reply
Subhash.p
August 8, 2020 at 10:53 am
Good article ...thank you sir
Parasuraman S
August 8, 2020 at 11:00 am
Good work! It would have been better, if you had mentioned the voltages measured instead of just saying 'normal!' That would be a good guidance for others who take up such work!
Raj
August 9, 2020 at 6:28 am
Noted Sir, Will do it in future. thanks much
Maynell Rodrigues
August 10, 2020 at 2:46 pm
Hi Raj sir I have the avr2312 and one day the power supply board sparked on inspection there was a burnt trace in the primary section fuse was blown 2diodes were found shorted. So I replaced all the diodes and repaired the traces. On powering on the fuse blew and all the diodes shorted out. Plz help me find a solution
Yogesh Panchal
August 14, 2020 at 1:41 am
Maynell Rodrigues,
Always use series bulb for this type of repairing.
you can get the idea from Jestine Sir's E book about SMPS Repair.
Maynell Rodrigues
December 28, 2020 at 7:10 pm
I have used series bulb. The power button light comes on but no display. Also the 100w bulb was around 75% bright. The top258mg does not have any shorts. Diodes D9004/3 were found shorted. There is short between LF902. And trace was burnt between -ve side of d9005 and d9006.
Michael Dsouza
April 6, 2024 at 3:47 am
i have the same amplfier, which is totally dead, have checked the smps i am getting the solid 5.2volt, but still the set is not getting powered, kindly advise where do i look for the faulty components
Albert van Bemmelen
August 8, 2020 at 1:02 pm
Excellent job Raj! I guess that with "Connected the power supply to the SMPS board alone." you meant that you plugged in the power cord into the SMPS board with unconnected outputs to test it stand-alone?
Raj
August 9, 2020 at 6:28 am
yes, you are right. thanks much
Yogesh Panchal
August 8, 2020 at 4:14 pm
Hi RAJ,
Welcome to the knowledge school........
Waleed Rishmawi
August 8, 2020 at 10:10 pm
Very dood repair job. Keep up the good work
Henrique J. G. Ulbrich
August 8, 2020 at 11:40 pm
Excellent, Mr. Raj. Just one thing was not clear: In step 3 you say that the connector was desoldered. But if it is just a connector, you must simply take it out, without desoldering.
Humberto
August 9, 2020 at 12:35 pm
Good repair,and thanks for sharing your expertises.
Richi
February 28, 2021 at 8:34 pm
Same fault the set is not on
Dudi16
January 27, 2024 at 9:05 pm
I have 13v AC between (output) gnd-gain and 13v AC between gnd- d.5.2, Is the same problem of this article or not? Thank you so much