Humming Sound In Yamaha PSR e403 Keyboard
My nephew called me to check on his Yamaha Keyboard with the problem of humming sound. On testing I observed the humming sound coming from both the speakers and it kept gradually increasing. Hence we opened the keyboard for inspection.
This type of Humming sound problem are most likely due to either earthing problem or due to some faulty capacitors hence I decide to directly check the amplifier section.
On visualize inspection everything looks ok. I have removed the PCB; there are very few components on this section.
So I have downloaded IC data from the internet for reference for IC BA 5417 and I have decided to test the capacitors which are directly grounded from IC (Because I am getting Humming from both the speakers if you get humming from only one speaker then test respected output pins i.e. pin number 2-3 and 5-6) so I have started with big capacitor which is connected to pin no 4 and 8 which is supply voltage to IC.
I found the 1000uf 25 volt e-cap bad and this is the reason why it causes the humming sound.
After replacing the capacitor I powered “ON” the Keyboard and tested it for ½ an hour. The humming sound was gone. My nephew was so happy and I can’t describe in words about his expression.
This article was prepared for you by Yogesh Panchal who works as a Computer Hardware Engineer in Mumbai India.
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Waleed Rishmawi
January 23, 2015 at 9:49 am
capacitors usually the cause for such humming. a job well done on the repair. keep up the good work
joe
January 23, 2015 at 10:37 am
Wish we could see if the top of that cap was bloated... Cap failed ESR?
Robert Calk
January 23, 2015 at 11:38 am
Good job Yogesh. Thanks for the article.
Mohamed Sittiq M
January 23, 2015 at 11:54 am
Thanks for your information for sharing..
Regards
Mohamed Sittiq M
Mark
January 23, 2015 at 3:48 pm
Well done Yogesh.
Did you test the caps for high ESR? Is that how you found the fault?
Chridtopher Babu Reddy
January 23, 2015 at 4:10 pm
good job done thank you keep it up
Lyudmil Barosov
January 23, 2015 at 5:38 pm
Hello.Thanaks a lot for information.
Some times are used capacitors with undervoltage needed.And when appear signal it is added or substracted from that voltage,and the capacitor maybe damaged.For example if the capacitor is for 20 volt and we give it 22 volt sinusoidal
on the positive picks the voltage will be 31volt and on the negative part of the sisus
signal the voltage across the capacitor will be
9 volt,so the positive picks can damage the
capacitor.By the way the oscilloscope is repaired.Mr Yong you were right.The problem
was in the horizontal part of the schematic.
One transistor was shorted-between C-E.KC509
Bestregards.
Barosov
Mike Zook
January 23, 2015 at 7:57 pm
Good job Yogesh, Keep up the good work. Thanks for the post.
Sethu ramachandran
January 23, 2015 at 9:43 pm
good job done yogesh.. . your Repair article should boost the service partners to migrate to repair all types of Electronic products
Thanks and good luck to u.
Humberto
January 24, 2015 at 12:25 am
Hi Yogesh Panchal, this e-cap causes a lot of hum that goes out for the speakers, its ESR value must be high. Anyway congratulations for your repair.
Yogesh Panchal
January 24, 2015 at 1:09 pm
Thanks everybody for your comments.
I don’t have ESR meter or capacitance meter yet; I just took a chance because most of time I have directly replaced the capacitors which are directly grounded from IC voltage supply Pin in audio system with Humming problem and capacitors also not that much expensive. Infect I keep some capacitors spare with me for testing purpose also i.e.
1000uf 25V
470uf 25V
220uf 10V
47uf 16V
100uf 16V
10uf 50V
Thanks.
living
November 19, 2016 at 6:24 pm
After changing th d 1000 uf 25v capacitor Im still getting the buzzy noise
Prashant Patil
March 12, 2017 at 7:38 am
Hiiii sir , i am having problem of huming in 1 speaker of my psr e 203 wind redio type huming coming from 1 speaker any solution for that
Ed
January 26, 2015 at 7:40 am
Keep up the good work
Tito
January 26, 2015 at 9:22 pm
Good article Yogesh. Capacitors are a problem nowadays sometimes if not bloated they just leak.
Joshua Oloo
January 29, 2015 at 12:36 am
Thanks Mr. Yogesh for the article.keep the fire burning.Cheers.
Albert Hoekman
February 2, 2015 at 6:43 pm
Nice job and explanation, thanks.
Nitram Mosay
February 3, 2015 at 11:50 pm
Hi Mr Yogesh Panchal,
Thank you very much for sharing your information with us,nice article.
Best regards
Nitram Mosay PNG
peter
February 10, 2015 at 5:34 am
Experience has directed you to a suspect capacitor on the supply board.
Quick low cost replacement probably quicker than testing & it worked.
Good instincts but I think you should buy an ESR meter which will sooner or later help your repair work.
AKASH GUNJAL
July 13, 2015 at 12:34 pm
GOOD WORK! BUT HOW DO YOU KNEW THE EXACT CAPACITOR WAS GONE WRONG
Venu shankar
February 19, 2018 at 7:13 pm
I have a problem with my PSR 403 keyboard
When I press any key and getting two notes tone ( exp: press C and getting C and F# , same like all the keys )
Plz anyone tell me what is the issue and how to solve
Opeyemi Daniel
March 2, 2018 at 12:31 am
HELP!!!
My yamaha keyboard has the same issue but i tried changing the 1000uf 25v capacitor but it still has the same issues..
i do not know much about testing capacitors. any help?
Also whatever help i can get
MS
June 27, 2018 at 6:55 pm
hi every one
my Yamaha PSR E-233 working eavery thing ok but no sound. Display all ok what is the reson IC BA 1547 already im changed but still same any idea