Router and Power Supply information - Bad Capacitors

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DaveMcLain
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PostPosted: Wed Aug 26, 2009 23:28    Post subject: Reply with quote
I had one blow up in a Fender Twin Reverb amp that I was getting going again for a guy who bought after it had sat unused for many years. I heard a hissing sound and then before I could flip the switch it exploded and blew foil and paper all over the shop! Nasty.

I always sort of figured that the old ones contained PCB's too.
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Radioman193
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PostPosted: Thu Aug 27, 2009 0:44    Post subject: Reply with quote
DaveMcLain wrote:
I had one blow up in a Fender Twin Reverb amp that I was getting going again for a guy who bought after it had sat unused for many years. I heard a hissing sound and then before I could flip the switch it exploded and blew foil and paper all over the shop! Nasty.

I always sort of figured that the old ones contained PCB's too.


yup

you shuld see what large caps will do lol
ad5mb
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PostPosted: Thu Aug 27, 2009 1:03    Post subject: Reply with quote
Quote:
The problems with the premature failure of many "modern" electrolytics is well documented, and is basically due to manufacturing errors/defects and poor quality control.


Oh, no. The story is much better than that.

Taiwanese engineer gets a job, with intent to commit industrial espionage. gets his big chance. grabbed the file and photocopied all four pages.

didn't know about the fifth page. describing the stabilizing agent. straight out of Indiana Jones.

a bazillion caps were made using the deficient highly secret formula. they seem to have been made even after the purloined formula was found to be defective.

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jkutianski
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PostPosted: Thu Aug 27, 2009 2:20    Post subject: Reply with quote
redhawk0 wrote:
OK...with a dremel tool and a cut-off wheel...I opened up the power brick.


The best way to do it is using a hammer with two pieces of fabric, one bottom and one top and use the hammer.
KeithB
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PostPosted: Sun Sep 06, 2009 12:01    Post subject: Reply with quote
ad5mb wrote:
Oh, no. The story is much better than that.

Taiwanese engineer gets a job, with intent to commit industrial espionage. gets his big chance. grabbed the file and photocopied all four pages.

didn't know about the fifth page. describing the stabilizing agent. straight out of Indiana Jones.

a bazillion caps were made using the deficient highly secret formula. they seem to have been made even after the purloined formula was found to be defective.


Yup, that's the documented story I read several years ago when the motherboard problem with bad caps was rampant.

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Masterman
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PostPosted: Sun Sep 06, 2009 14:07    Post subject: Reply with quote
Damn, I just ordered a WL 500W Asus. Thank god for their 2 year warranty...
Pawkrz74
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PostPosted: Tue Feb 09, 2010 21:55    Post subject: Re: Router and Power Supply information - Bad Capacitors Reply with quote
redhawk0 wrote:

Bad capacitors...notice the domed tops...they should be perfectly flat.
one 16V@1000uF, and two 16V@470uF

My ones were completly flat, but the router's was working simillar to description (LEDS, firmvare restoration allwys completed, but during "Radio ON" it was, and stil is losing the connection via LAN and WiFi, with "Radio OFF" it worked fine but there was no WiFi). I exchanged the capacitors (but I putted 6,3V@1000uF as was oryginally) it helped a little bit, now it works for an hour with "Radio ON" and after that time starts to disconnect, connect ...
Does enyone knows the reason, should I exchange this 1000uF capacitor with 16V one, or there is something else.
Thanks in adwance.
PawKrz74
flei
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PostPosted: Sun Mar 14, 2010 11:01    Post subject: Reply with quote
Is there model that 1000uF capacitor is 16V?

I have two 470uF/16V capacitor and one is 1000uF/6,3V. 1000uF capacitor is round at the top and I am going to change it, should I replace it with 16V capacitor.

Should I maybe change 470uF capacitors also?
redhawk0
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PostPosted: Sun Mar 14, 2010 12:12    Post subject: Reply with quote
flei wrote:
Is there model that 1000uF capacitor is 16V?

I have two 470uF/16V capacitor and one is 1000uF/6,3V. 1000uF capacitor is round at the top and I am going to change it, should I replace it with 16V capacitor.

Should I maybe change 470uF capacitors also?


Yes....16V are fine....and yes...change all 3 caps.

Most likely your power supply also has a bad cap.

redhawk

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crashfly
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PostPosted: Sun Mar 14, 2010 16:20    Post subject: Reply with quote
An excellent place to purchase the "exact" specifications for your bad capacitors is at http://www.mouser.com. It would appear they also have an 'international' part of their company which covers many countries.

I have gotten my replacement caps from them multiple times. Usually talking cheap for what you pay and if you need to get large quantities, it gets a bit cheaper.

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slybunda
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PostPosted: Sun Mar 14, 2010 17:00    Post subject: Reply with quote
i dont get it, am i the only person on here that replaces failed electrolyte caps with solid polymer ones?
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PostPosted: Sun Mar 14, 2010 17:53    Post subject: Reply with quote
slybunda wrote:
i dont get it, am i the only person on here that replaces failed electrolyte caps with solid polymer ones?

What benefit would that do? In addition, what is the cost difference on changing to that type?

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redhawk0
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PostPosted: Sun Mar 14, 2010 18:07    Post subject: Reply with quote
Sure...Solid Polymer Caps are a good choice...but for the cost...probably not so much.

The real advantage is the SP Caps will take more heat and not break down like the standard electrolytic type.

In a Power supply...SP caps might be best (seeing it is an enclosed supply and temps get higher)...but in a router itself...probably not as cost effective.

You also have to remember that the SP caps are larger then the electrolytics...they can't pack the same capacitance into the small size package like those found in standard electrolytics.

redhawk

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kusanagi-sama
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PostPosted: Thu Sep 16, 2010 3:26    Post subject: Reply with quote
KeithB wrote:
ad5mb wrote:
Oh, no. The story is much better than that.

Taiwanese engineer gets a job, with intent to commit industrial espionage. gets his big chance. grabbed the file and photocopied all four pages.

didn't know about the fifth page. describing the stabilizing agent. straight out of Indiana Jones.

a bazillion caps were made using the deficient highly secret formula. they seem to have been made even after the purloined formula was found to be defective.


Yup, that's the documented story I read several years ago when the motherboard problem with bad caps was rampant.


Also, this is what caused Abit to go out of business due to all the lawsuits that were brought to them because of the bad caps

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.AbrahaM.
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PostPosted: Sun Dec 12, 2010 19:45    Post subject: Reply with quote
thx-1138 wrote:
Hello Redhawk0,

Great finding! I will physically inspect my Asus WL-500g Premium to look out for the same issue. It makes sense that unreliability will drop into a device if it has bad capacitors; I have seen it many times with personal computers but never on routers. Thank you for sharing this important information with all of us.


For the record:
Recently I fixed ASUS WL-500gP by exchanging one capacitor (AFAIR 16V@470uF) AND exchanging flauty power supply
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