Badcaps.net Forum
Go Back   Badcaps Forums > Electronics Theory and Troubleshooting > Audio Equipment Discussion
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 09-21-2017, 06:25 PM   #1
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Sony Wireless Headphones MDR-RF820

Hello, guys.

I was wondering if you could help me identify the source of the problem. I have these wireless headphones from Sony which worked flawlessly until recently. Now, when they turn on, intermittent hissing is heard, combined with a very short hiss every two seconds. This happens regardless of the position from the transmitter.
To be on the safe side, I took mu headset to my sister's as she too has the same model of headphones and the hiss is not heard when connected to her base/transmitter. So it must be my transmitter that is sending this hiss sound. Also, when I turn the transmitter off, I can turn the headphones Tune knob and pick some local radio stations which sound normal and without hiss. So the headset seems to work fine and must be receiving the hiss from the transmitter.
I have included a few photos of the transmitter PCB if it could be of any assistance. The black caps are all Rubycon YK series, most of them are 50v10uf, 50v22uf and one 50v4.7uf. The green ones are Sam Young 16v100uf and two 50v2.2uf. The blue ones are Lelon 16v220uf. None of them seems or looks defective.
Do you have some idea as to what could be causing this repetitive hiss, mixed with additional intermittent hissing sounds? Thanks in advance for any assistance, as always.
Attached Images
File Type: jpg 20170922_020106.jpg (479.4 KB, 16 views)
File Type: jpg 20170922_020131.jpg (544.3 KB, 17 views)
File Type: jpg 20170922_020159.jpg (636.8 KB, 14 views)

Last edited by UserXP; 09-21-2017 at 06:32 PM..
UserXP is offline   Reply With Quote
Old 09-23-2017, 04:39 AM   #2
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Re: Sony Wireless Headphones MDR-RF820

I know that "white noise" is normal for this type of wireless headphones, it's just that it got worse and additional noise is present. The weird thing is that it happens/intensifies in regular time intevals, which led me to suspect that maybe some capacitor went bad and is "leaking" the noise. I am sorry for being unable to somehow record the noise and hiss sounds and put them here (if it actually would be of some assistance, please direct me on how to do it). Thanks in advance for any assistance. :-)
UserXP is offline   Reply With Quote
Old 09-23-2017, 06:58 AM   #3
sam_sam_sam
Badcaps Veteran
 
Join Date: Jul 2011
City & State: Sunny Jacksonville FL
My Country: USA
Line Voltage: 120 Volts 60 HZ
I'm a: Knowledge Seeker
Posts: 616
Default Re: Sony Wireless Headphones MDR-RF820

Quote:
Originally Posted by UserXP View Post
The green ones are Sam Young 16v100uf and two 50v2.2uf. The blue ones are Lelon 16v220uf. None of them seems or looks defective.
Do you have some idea as to what could be causing this repetitive hiss, mixed with additional intermittent hissing sounds? Thanks in advance for any assistance, as always.

If I were doing this repair

Just because they have not pop there tops or bottoms that does not mean that they are still good
When I see these brands or ones that I have not seen before I replace them on sight

I would replace all of the caps that you have above
__________________
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Desk Top Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *


These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

1 Over Head Crane Current Sensing Board
2 Hem Saw Computer Stack Board

All of these had CAPs POOF
All of the mosfet that are taken out by bad caps

Last edited by sam_sam_sam; 09-23-2017 at 07:02 AM..
sam_sam_sam is offline   Reply With Quote
Old 09-23-2017, 12:11 PM   #4
momaka
Badcaps Veteran
 
momaka's Avatar
 
Join Date: May 2008
City & State: VA (NoVA)
My Country: U.S.A.
Line Voltage: 120 VAC, 60 Hz
I'm a: Hobbyist Tech
Posts: 7,214
Default Re: Sony Wireless Headphones MDR-RF820

Well, looks like a lot of the FM receiver stuff is in a metal box, so probably not much to go wrong with that. Thus, I suggest to start by replacing the caps. Of course, before you do that, try some fresh batteries. It would be too funny if that's all it takes to "fix" this issue. I'm sure you probably tried that already, but just mentioning it anyways - sometimes simple problems are overlooked and interpreted as much more complex ones - at least it's happened to me quite a few times.
momaka is offline   Reply With Quote
Old 09-23-2017, 03:23 PM   #5
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Re: Sony Wireless Headphones MDR-RF820

Thank you all for your suggestions.

@Sam:
I was thinking to do that, and I actually looked on eBay from that one seller who has original Rubycons (his name is egekecu or something similar), I ordered before and all was OK. But there are 5 different cap values involved for the base, and it went to around 30$ for the cap packs (as he sells in packs of 10pcs or so). I will check with the seller if he could customize the order.

@Momaka
I agree, I to had similar situations. I fully recharged the batteries and it didn't help at all. I found a "mod" for these headphones' bateries. Original ones had square inserts on the battery ends. So I removed those and it turned out it could be fitted on any AAA rechargeable battery. Since then, I am using Duracell AAA rechargeable batteries in these headphones and the base has always charged them nicely as if they were original ones. This workaround was also much cheaper solution than ordering a pair of original batteries from Sony.

I am very tempted to try with the recapping, but I also am not sure whether it will make any difference or I would be just throwing money. Do you think these existing Rubycons have gone bad, or should I just order replacement caps for the non-Rubycon ones?

I managed to open the headset as well, but I forgot to take pictures of it. The PCB in it also had several caps and they were all tiny or short in hight. The headset operates on two AAA batteries, so I don't think the cap values are high, especially with their small size. They were also very tightly positioned to each other, making it very difficult to see the readings. They too looked fine, but I am not sure as to what brand they are. :/

If it would help ypu to see those imagges as well, please let me know, I will reopen the headset's right cap and take some photos for you.

Last edited by UserXP; 09-23-2017 at 03:44 PM..
UserXP is offline   Reply With Quote
Old 09-23-2017, 04:50 PM   #6
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Re: Sony Wireless Headphones MDR-RF820

Here is what I could find if I were to use Rubycons. Please take a look at the series and suggest which of them would be fine for the radio transmitter base. I selected these as they match size and diameter of the original ones. These are for the base only:

50V2.2uf:
YXG Series

50V4.7uf:
YXF Series

50V10uf:
YXA Series
YXF Series

50V22uf:
YXF Series
YXM Series
YXG Series

16v100uf:
YXA Series
YK Series
ZLH Series

16v220uf:
YK Series
ZLH Series

Last edited by UserXP; 09-23-2017 at 04:56 PM..
UserXP is offline   Reply With Quote
Old 09-26-2017, 03:39 PM   #7
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Re: Sony Wireless Headphones MDR-RF820

Any thoughts on these available series?
UserXP is offline   Reply With Quote
Old 10-01-2017, 12:15 PM   #8
momaka
Badcaps Veteran
 
momaka's Avatar
 
Join Date: May 2008
City & State: VA (NoVA)
My Country: U.S.A.
Line Voltage: 120 VAC, 60 Hz
I'm a: Hobbyist Tech
Posts: 7,214
Default Re: Sony Wireless Headphones MDR-RF820

Quote:
Originally Posted by UserXP View Post
@Sam:
I was thinking to do that, and I actually looked on eBay from that one seller who has original Rubycons (his name is egekecu or something similar), I ordered before and all was OK. But there are 5 different cap values involved for the base, and it went to around 30$ for the cap packs (as he sells in packs of 10pcs or so). I will check with the seller if he could customize the order.
Yes, definitely ask him if he can do a custom order. Otherwise, $30 for cap for an old pair of headphones is a bit high (especially when we don't even know if the caps will fix the problem or not). Instead, you could get a cheap capacitor/transistor tested from China for that price and check the caps, then replace only the ones that *may* be bad.

Alternatively, you could buy some cheap knock-off caps available in your country and see if that fixes the issue. The cheap caps may not be the best quality or last long, but at least you might find out if that's the issue or not.

Better yet, find an old discarded CRT TV from the 90's or early 2000's - those will have plenty of the caps you need - especially Sony (they use mostly Rubycon and Nichicon inside).

Quote:
Originally Posted by UserXP View Post
@Momaka
I agree, I to had similar situations. I fully recharged the batteries and it didn't help at all. I found a "mod" for these headphones' bateries. Original ones had square inserts on the battery ends. So I removed those and it turned out it could be fitted on any AAA rechargeable battery. Since then, I am using Duracell AAA rechargeable batteries in these headphones and the base has always charged them nicely as if they were original ones. This workaround was also much cheaper solution than ordering a pair of original batteries from Sony.
Nice!

By the way, do you use these headphones over a large distance? Because if not, then turning them into wired headphones may be another option. I did that with a wireless pair of RCA headphones, because they sounded pretty poor over wireless (no bass and signal wasn't as clear as I thought it would be). Now I can't take them off my head - they sound pretty darn good over a wired connection.

Quote:
Originally Posted by UserXP View Post
I am very tempted to try with the recapping, but I also am not sure whether it will make any difference or I would be just throwing money. Do you think these existing Rubycons have gone bad, or should I just order replacement caps for the non-Rubycon ones?
The existing Rubycon caps are probably okay, but the blue Lelon REA caps (or for that matter, any Lelon) might not be. If you do a recap, maybe just start with the Lelon and any other non-Rubycon caps.

On that note, have you checked the caps in the power supply / power adapter for the base, or just tried a different power adapter altogether? Perhaps that's causing the issues.

Quote:
Originally Posted by UserXP View Post
Any thoughts on these available series?
They are all fine. There's no high-power switching circuits inside these headphones, so the ESR of the caps probably does not matter that much. Hence, any cap will probably do.

Last edited by momaka; 10-01-2017 at 12:18 PM..
momaka is offline   Reply With Quote
Old 10-01-2017, 12:45 PM   #9
Wester547
-
 
Join Date: Nov 2011
City & State: CA.
My Country: USA.
Line Voltage: 120-125VAC 60Hz.
I'm a: Knowledge Seeker
Posts: 1,117
Default Re: Sony Wireless Headphones MDR-RF820

Quote:
Originally Posted by UserXP View Post
Any thoughts on these available series?
I actually recommend avoiding egekecu as he is selling counterfeit Nichicon HDs (they shouldn’t have brown sleeves):

Link

Others have had unexplainable issues when ordering caps from that seller in the past as well. Such issues that can only be explained by counterfeit capacitors:

https://www.badcaps.net/forum/showthread.php?t=8312

https://www.badcaps.net/forum/showpo...1&postcount=28
Wester547 is offline   Reply With Quote
Old 10-02-2017, 11:37 AM   #10
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Re: Sony Wireless Headphones MDR-RF820

Hi.
Thanks for the reference, it is certainly not reassuring. The Rubycons MBZ that i bought from him a few years ago are still good. I actually was considering other options for ordering but the shipping costs are horrible and are usually twice the cost of the caps to be ordered, whereas this seller offers free economy shipping.

To be on the safe side, what brand/type of capacitors would be a great replacement for my transmitter? I opened my sister's transmitter this weekind and it has only Rubycons inside (which is probably why her set works fine regardless of the fact that it is a few years older than mine) and all are YK series. If go for Rubycons, is this series still being manufactured? If not, which existing series would be OK? I reckon that the YK series is a general purpose capacitor.
UserXP is offline   Reply With Quote
Old 10-02-2017, 06:24 PM   #11
momaka
Badcaps Veteran
 
momaka's Avatar
 
Join Date: May 2008
City & State: VA (NoVA)
My Country: U.S.A.
Line Voltage: 120 VAC, 60 Hz
I'm a: Hobbyist Tech
Posts: 7,214
Default Re: Sony Wireless Headphones MDR-RF820

Quote:
Originally Posted by UserXP View Post
To be on the safe side, what brand/type of capacitors would be a great replacement for my transmitter? I opened my sister's transmitter this weekind and it has only Rubycons inside (which is probably why her set works fine regardless of the fact that it is a few years older than mine) and all are YK series. If go for Rubycons, is this series still being manufactured? If not, which existing series would be OK? I reckon that the YK series is a general purpose capacitor.
YK is general purpose.

That said, whenever you see electrolytic capacitors with 85°C temperature rating, you can pretty much safely assume that they are general purpose.

Of course, you could use low-ESR caps too. Like I said, you won't see any high-power switching circuits in the transmitter base, so the ESR of the caps does not matter much.

Quote:
Originally Posted by Wester547 View Post
I actually recommend avoiding egekecu as he is selling counterfeit Nichicon HDs (they shouldn’t have brown sleeves):

Link
Could be just a custom order. The bungs in the picture look correct from the side and the printing on the sleeve is also pretty good.

The only real question is who ordered these and how long have they been sitting.

I suspect the other complaints could be just rare individual cases too - after all, even the Japanese caps don't have a perfect track record. I had a Panasonic FJS bulge on an ASUS A8V-MX motherboard for no reason (the one I posted here a few months back). Cap wasn't in a stressed or hot spot. Just died. I have another Panasonic FL out of an Xbox 360 that reads open-circuit most of the time and just a few picoFarads sometimes. TC had a bunch of Rubycon MBZ go high-ESR on him as well, if I recall correctly from that thread awhile back.

I'm not trying to side with egekecu, but I just think that some of the complaints against him aren't really 100% justified.

That said, of course I also recommend getting caps from badcaps.net, Digikey, Mouser, and many of the other big online stores over anyone on eBay. But egekecu is probably alright *most* of the time too.

Last edited by momaka; 10-02-2017 at 06:26 PM..
momaka is offline   Reply With Quote
Old 10-02-2017, 07:09 PM   #12
Wester547
-
 
Join Date: Nov 2011
City & State: CA.
My Country: USA.
Line Voltage: 120-125VAC 60Hz.
I'm a: Knowledge Seeker
Posts: 1,117
Default Re: Sony Wireless Headphones MDR-RF820

Quote:
Could be just a custom order. The bungs in the picture look correct from the side and the printing on the sleeve is also pretty good.
Nichicon HD’s datasheet specifies a black sleeve with white print. The font actually looks off to me. And the prefix “C”, on the datecode / factory code, means it came from China, so it could definitely be counterfeit.

Quote:
I suspect the other complaints could be just rare individual cases too - after all, even the Japanese caps don't have a perfect track record. I had a Panasonic FJS bulge on an ASUS A8V-MX motherboard for no reason (the one I posted here a few months back). Cap wasn't in a stressed or hot spot. Just died.
I found that bulge of that FJ (in the picture you provided) to be very moderate compared to the way a Sacon FZ or even NCC KZG would explode given the volatile electrolyte of both series.

I also find it hard to believe that even one 3300µF 6.3V Panasonic FJ would bulge and leak on its original looms, full leads intact, without having ever been placed in a circuit before, three years after the date it was manufactured. Even KZG and KZJ usually last longer than that before they bulge on their own. I don’t know, it just seems fishy to me, and 99.9% of the caps on eBay are known fakes. This thread is another example - a supposedly genuine NCC KY capacitor measuring out-of-spec for no apparent reason:

https://www.badcaps.net/forum/showthread.php?t=33102

The vent stamp on the Panasonic FJ that c_hegge ordered from the same seller, all those years ago, looks different than those on real Panasonic capacitors. Something about the vent stamp seems off, as I believe the curved T-vent stamp on real Panasonic capacitors is scored a bit thinner.

Quote:
I have another Panasonic FL out of an Xbox 360 that reads open-circuit most of the time and just a few picoFarads sometimes.
So you found a Panasonic FL that read open-circuit out of an Xbox 360 motherboard? If memory serves, that had its seal abused (someone pulled too hard on the wire leads) so it wouldn’t surprise me if it failed.

Quote:
TC had a bunch of Rubycon MBZ go high-ESR on him as well, if I recall correctly from that thread awhile back.
IIRC, those MBZ came out of IBM / Lenovo Thinkcentre hotplate SFF desktops that ran 24/7 for 4-6 years. In fact, the FETs and coils on those motherboards tend to run very hot, and most of the MBZ dried up rather than violently outgassed, so I don’t think it’s necessarily anything more than a normal end-of-life failure for a 2,000 hour at 105şC rated capacitor.

Of course I realize what you are trying to say... random failures do occur no matter the component or brand. Bigbeark had a batch of 820µF 6.3V FJ that went high ESR for no reason, five years ago. The 1500µF 6.3V and 1000µF 16V KZG on that board were starting to silently fail too, no surprise there, but not as badly as the FJ.

Still, I think it’s best to avoid eBay if possible.

Last edited by Wester547; 10-02-2017 at 07:18 PM..
Wester547 is offline   Reply With Quote
Old 10-03-2017, 07:15 AM   #13
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Re: Sony Wireless Headphones MDR-RF820

Thanks a lot, Momaka and Wester547.
I will do some testing with the locally available caps, then. I doubt they cost more than 10 cents a piece in a local store, though they are probably of not so good a quality. I remember that last time I checked they had Jamicon and Fujicon caps rated at 105°C, so I suppose they have those in various ratings also. Although I might be doing a double resoldering-soldering job, at least it might provide some insights into whether recapping would erradicate the problem or not. If it does, I will go for the Rubycons to match the original Sony specs and quality.
I will post the results and findings here.
UserXP is offline   Reply With Quote
Old 10-11-2017, 06:46 AM   #14
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Re: Sony Wireless Headphones MDR-RF820

I have ordered Rubycon YK series caps to replace only the non-Rubycon ones. I could not find such small caps of all the required ratings in a local store, so I ordered from egekecu. Once they have arrived, I will post pictures and results of the recapping.
UserXP is offline   Reply With Quote
Old 10-11-2017, 09:51 AM   #15
momaka
Badcaps Veteran
 
momaka's Avatar
 
Join Date: May 2008
City & State: VA (NoVA)
My Country: U.S.A.
Line Voltage: 120 VAC, 60 Hz
I'm a: Hobbyist Tech
Posts: 7,214
Default Re: Sony Wireless Headphones MDR-RF820

Cool. Keep us updated. Be interesting to know if the caps really were the problem here.
momaka is offline   Reply With Quote
Old 10-12-2017, 05:28 PM   #16
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Re: Sony Wireless Headphones MDR-RF820

Quote:
Originally Posted by momaka View Post
Cool. Keep us updated. Be interesting to know if the caps really were the problem here.
Sure thing.
UserXP is offline   Reply With Quote
Old 10-12-2017, 05:33 PM   #17
petehall347
Badcaps Veteran
 
Join Date: Jan 2015
City & State: worcester
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 704
Default Re: Sony Wireless Headphones MDR-RF820

did you try the whole setup at your sisters ?
petehall347 is offline   Reply With Quote
Old 10-13-2017, 04:55 AM   #18
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Re: Sony Wireless Headphones MDR-RF820

Quote:
Originally Posted by petehall347 View Post
did you try the whole setup at your sisters ?
Yes. When I:
- tune my headset to her base transmitter, noise is not present.
- tune my headset to my base transmitter, noise is present.
- tune her headset to my base transmitter, noise is present.

Both her and my headset can pick up some local radio stations and reproduce hissless audio output, so the headsets must be fine, right?

Do you have any specific idea I did not try?

Also, I opened her base transmitter to sse its inners. Everything is identical to mine, except hers has only Rubycons YK series and no other brands, plus her base has a fourth 16v220uF Rubycon cap near the DC plug. My PCB doesn't have that one but there are markings and holes on the PCB where the additional cap could be soldered (I think it is visible in one of the included pictures from the initial post). Can that mean a difference all of a sudden?

Last edited by UserXP; 10-13-2017 at 05:14 AM..
UserXP is offline   Reply With Quote
Old 10-14-2017, 02:09 PM   #19
momaka
Badcaps Veteran
 
momaka's Avatar
 
Join Date: May 2008
City & State: VA (NoVA)
My Country: U.S.A.
Line Voltage: 120 VAC, 60 Hz
I'm a: Hobbyist Tech
Posts: 7,214
Default Re: Sony Wireless Headphones MDR-RF820

Quote:
Originally Posted by UserXP View Post
Also, I opened her base transmitter to sse its inners. Everything is identical to mine, except hers has only Rubycons YK series and no other brands, plus her base has a fourth 16v220uF Rubycon cap near the DC plug. My PCB doesn't have that one but there are markings and holes on the PCB where the additional cap could be soldered (I think it is visible in one of the included pictures from the initial post). Can that mean a difference all of a sudden?
Yes it could.
If they removed that cap as a cost-cutting measure, the circuit function could have been marginal to begin with, but still enough to last a while. As things age - particularly caps - ripple and noise can start to get high enough that not having that capacitor makes the difference between a functional and non-functional circuit.

So on that note, it's probably not a bad idea to get a spare cap and fill that spot too. Might as well if you are ordering other caps.
momaka is offline   Reply With Quote
Old 10-15-2017, 02:54 AM   #20
UserXP
Senior Member
 
Join Date: Apr 2012
City & State: Niš, Serbia
My Country: Serbia
Line Voltage: 220VAC 50Hz
I'm a: Knowledge Seeker
Posts: 118
Default Re: Sony Wireless Headphones MDR-RF820

Yes, I have ordered a few more caps than necessary, so I shall put one in there too - once they have arrived, that is (still waiting ). I really hope this will be a goog fix.
UserXP is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums © 2003 - 2017
Powered by vBulletin ®
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 12:43 AM.

Did you find this forum helpful?