PDA

View Full Version : DLink using bad caps?



Eric
03-21-08, 07:32 PM
Hi,

As I recently posted, one of my main wireless routers (DI-764 802.11a/b)
finally died completetly after six years of use. The 802.11a radio had died
a few months back, but by then I was only using the router portion of the
DI-764 as I had a WAP (DWL-7100AP 802.11a/gb) attached to it.

I've since ordered a wired router to replace the old DI-764 (waiting on it
to arrive from Newegg), but thought I would play around with the old DI-764
and see if I could actually fix the thing. Upon opening it up, I noticed
that one cap had completely bursted while another one was buldging. First
trip to a Radio Shack proved fruitless as that particular store (at a mall)
no longer sold components. The sales clerk didn't even know what a
capacitor was. She kept asking me if it was some sort of interconnect!

Anyway, today while lunch at work, I went to a regular Radio Shack and got
new caps. I then soldered the new caps onto the mainboard and the DI-764,
to me disbelief, was fully operational again!

Once I got home, I decided to look into another D-Link WAP that I have since
it has just started acting a little flakey. Sure enough, one of the caps
inside it is starting to buldge. This particular WAP has only been running
for a little over a year.

Ok, I guess I shouldn't really complain about six years of 24/7 operation,
but should they be crapping out after only a year? Is D-Link saving a few
pennies by using poor quality caps?

miso@sushi.com
03-22-08, 01:18 AM
On Mar 21, 5:32 pm, "Eric" <n...@nowhere.nnn> wrote:
> Hi,
>
> As I recently posted, one of my main wireless routers (DI-764 802.11a/b)
> finally died completetly after six years of use. The 802.11a radio had died
> a few months back, but by then I was only using the router portion of the
> DI-764 as I had a WAP (DWL-7100AP 802.11a/gb) attached to it.
>
> I've since ordered a wired router to replace the old DI-764 (waiting on it
> to arrive from Newegg), but thought I would play around with the old DI-764
> and see if I could actually fix the thing. Upon opening it up, I noticed
> that one cap had completely bursted while another one was buldging. First
> trip to a Radio Shack proved fruitless as that particular store (at a mall)
> no longer sold components. The sales clerk didn't even know what a
> capacitor was. She kept asking me if it was some sort of interconnect!
>
> Anyway, today while lunch at work, I went to a regular Radio Shack and got
> new caps. I then soldered the new caps onto the mainboard and the DI-764,
> to me disbelief, was fully operational again!
>
> Once I got home, I decided to look into another D-Link WAP that I have since
> it has just started acting a little flakey. Sure enough, one of the caps
> inside it is starting to buldge. This particular WAP has only been running
> for a little over a year.
>
> Ok, I guess I shouldn't really complain about six years of 24/7 operation,
> but should they be crapping out after only a year? Is D-Link saving a few
> pennies by using poor quality caps?

If you could photograph the bad caps and where they were located,
upload the photo, then readers at sci.electronics.design could
diagnose the problem.

I do salute your effort to fix the problem.

Jeff Liebermann
03-22-08, 11:18 AM
On Fri, 21 Mar 2008 19:32:11 -0500, "Eric" <none@nowhere.nnn> wrote:

>Ok, I guess I shouldn't really complain about six years of 24/7 operation,
>but should they be crapping out after only a year? Is D-Link saving a few
>pennies by using poor quality caps?

No, it's not really D-Links fault. Since about 1999, the entire
industry has been plagued by defective low-ESR electrolytic capacitors
with counterfeit electrolyte.
<http://en.wikipedia.org/wiki/Capacitor_plague>
<http://www.badcaps.net/>
The problem has been that there are so many defective capacitors in
circulation, that they end up in current products. Also, the delay
before they blow up varies with temperature and loading. A very hot
and high rippple current capacitor on a PC motherboard may blow up in
a few weeks, while the same capacitor, in a light duty and cooler
product, might take years.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Eric
03-22-08, 12:50 PM
"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:hqbau3d7b2b6v0oaghmgglbgdgh0v8trpj@4ax.com...
> On Fri, 21 Mar 2008 19:32:11 -0500, "Eric" <none@nowhere.nnn> wrote:
>
>>Ok, I guess I shouldn't really complain about six years of 24/7 operation,
>>but should they be crapping out after only a year? Is D-Link saving a few
>>pennies by using poor quality caps?
>
> No, it's not really D-Links fault. Since about 1999, the entire
> industry has been plagued by defective low-ESR electrolytic capacitors
> with counterfeit electrolyte.
> <http://en.wikipedia.org/wiki/Capacitor_plague>
> <http://www.badcaps.net/>
> The problem has been that there are so many defective capacitors in
> circulation, that they end up in current products. Also, the delay
> before they blow up varies with temperature and loading. A very hot
> and high rippple current capacitor on a PC motherboard may blow up in
> a few weeks, while the same capacitor, in a light duty and cooler
> product, might take years.
>

Hi,

Wow. I remember when computer motherboards were having problems with bad
caps, but didn't realize it was so broad....

Eric
03-22-08, 12:52 PM
<miso@sushi.com> wrote in message
news:a4e00918-1437-47e6-baa4-a8f8d32d1763@c19g2000prf.googlegroups.com...
> On Mar 21, 5:32 pm, "Eric" <n...@nowhere.nnn> wrote:
>> Hi,
>>
>> As I recently posted, one of my main wireless routers (DI-764 802.11a/b)
>> finally died completetly after six years of use. The 802.11a radio had
>> died
>> a few months back, but by then I was only using the router portion of the
>> DI-764 as I had a WAP (DWL-7100AP 802.11a/gb) attached to it.
>>
>> I've since ordered a wired router to replace the old DI-764 (waiting on
>> it
>> to arrive from Newegg), but thought I would play around with the old
>> DI-764
>> and see if I could actually fix the thing. Upon opening it up, I noticed
>> that one cap had completely bursted while another one was buldging.
>> First
>> trip to a Radio Shack proved fruitless as that particular store (at a
>> mall)
>> no longer sold components. The sales clerk didn't even know what a
>> capacitor was. She kept asking me if it was some sort of interconnect!
>>
>> Anyway, today while lunch at work, I went to a regular Radio Shack and
>> got
>> new caps. I then soldered the new caps onto the mainboard and the
>> DI-764,
>> to me disbelief, was fully operational again!
>>
>> Once I got home, I decided to look into another D-Link WAP that I have
>> since
>> it has just started acting a little flakey. Sure enough, one of the caps
>> inside it is starting to buldge. This particular WAP has only been
>> running
>> for a little over a year.
>>
>> Ok, I guess I shouldn't really complain about six years of 24/7
>> operation,
>> but should they be crapping out after only a year? Is D-Link saving a
>> few
>> pennies by using poor quality caps?
>
> If you could photograph the bad caps and where they were located,
> upload the photo, then readers at sci.electronics.design could
> diagnose the problem.
>
> I do salute your effort to fix the problem.

Hi,

Didn't even think of that... The bad caps have already made their way to a
dumpster...

Jeff Liebermann
03-23-08, 01:36 AM
On Sat, 22 Mar 2008 12:50:38 -0500, "Eric" <none@nowhere.nnn> wrote:

>> <http://en.wikipedia.org/wiki/Capacitor_plague>
>> <http://www.badcaps.net/>

>Wow. I remember when computer motherboards were having problems with bad
>caps, but didn't realize it was so broad....

I've seen it in power supplies, wireless devices, monitors, hi-fi
hardware, and various type of consumer electronics. Even the Apple
(Lucent) Airport wireless router has had problems:
<http://www.vonwentzel.net/ABS/Repair/>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558