2Wire 2701HG-B DSL router power supply repair

Oct 20, 2011 5 Replies
J

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:


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
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S

What about the smaller cap under the diode or is it just that same one?

G=B2

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N

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.

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J

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.

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
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J

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
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J

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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