2Wire 2701HG-B DSL router power supply repair

J

Jeff Liebermann

Guest
If your 2Wire 2701HG-B DSL modem/router/wireless acts strangely, it's
probably the power supply. I decided it was time to fix some 2Wire
power supplies:
<http://802.11junk.com/jeffl/pics/repair/2Wire-power-supply.jpg>
<http://802.11junk.com/jeffl/pics/repair/2Wire-power-supplies.jpg>
Three of the five had visibly bulging caps. I replaced the caps
(1000uF 16v) in all five power supplies as all of them showed high
ESR.

Cracking the case is easy. Insert in bench vise equipped with
rubber covered jaws, and compress until you hear the glue crack.
Repeat for all sides and it should just pop open. Duco cement to
seal back shut. Test with a 3.3 ohm 10 watt load resistor for 5.1VDC.

Repair before Recycling.

--
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
 
Jeff Liebermann <jeffl@cruzio.com> wrote in message
news:s24v97lnhpcdjsue0amscns91ld140s98p@4ax.com...
If your 2Wire 2701HG-B DSL modem/router/wireless acts strangely, it's
probably the power supply. I decided it was time to fix some 2Wire
power supplies:
http://802.11junk.com/jeffl/pics/repair/2Wire-power-supply.jpg
http://802.11junk.com/jeffl/pics/repair/2Wire-power-supplies.jpg
Three of the five had visibly bulging caps. I replaced the caps
(1000uF 16v) in all five power supplies as all of them showed high
ESR.

Cracking the case is easy. Insert in bench vise equipped with
rubber covered jaws, and compress until you hear the glue crack.
Repeat for all sides and it should just pop open. Duco cement to
seal back shut. Test with a 3.3 ohm 10 watt load resistor for 5.1VDC.

Repair before Recycling.

--
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
Click to expand...


Using a vice I crack the side with the cable out, first, as the case
"welding" is already weakened there. Then guitar plectrum to force open at
the corners. I assume Duco is a trade name for plumbing polythene waste pipe
solvent.
 
What about the smaller cap under the diode or is it just that same
one?

G˛
 
On Thu, 20 Oct 2011 08:42:38 +0100, "N_Cook" <diverse@tcp.co.uk>
wrote:

I assume Duco is a trade name for plumbing polythene waste pipe
solvent.
Click to expand...
It's a nitrocellulose and solvent concoction. Lots of acetone thrown
in to soften the plastic. Model airplane glue or dope would be a good
approximation. Works well with ABS. I picked it because it's brittle
and can be cracked again for rework.
<http://www.devcon.com/prodfiles/pdfs/fam_tds_207.pdf>
<http://www.devcon.com/products/products.cfm?familyID=207>

--
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
 
On Thu, 20 Oct 2011 00:15:51 -0700 (PDT), stratus46@yahoo.com wrote:

What about the smaller cap under the diode or is it just that same
one?
G˛
Click to expand...
Oops. I didn't check that capacitor. I'll crack one open later today
and check it. I don't think it's a problem because all 5 wall parts
had good clean output, at rated voltage, with a nearly full load.

--
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
 
On Thu, 20 Oct 2011 00:15:51 -0700 (PDT), stratus46@yahoo.com wrote:

What about the smaller cap under the diode or is it just that same
one?
G˛
Click to expand...
It's ok. I re-opened 2 of the 5 power supplies and tested the 470uf
10v smaller cap. They're fine. The output circuit is a PI section,
with the 1000uF 16v cap at the input, a choke, and then the 470uF 10v
cap. The 1000uF gets all the ripple current, which is probably what
killed it.

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