Passive PoE mod for TP-LINK TL-WR741ND

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gridrun
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Joined: 29 Oct 2011
Posts: 24

PostPosted: Sat Nov 19, 2011 23:03    Post subject: Passive PoE mod for TP-LINK TL-WR741ND Reply with quote
Hi all,

Here is how you can mod your TP-LINK TL-WR741ND (V2.0) for passive PoE.

1) Open the device by removing the rubber feet and the screws behind them at the indicated positions. Once done, pull both the upper and the lower half of the case gently apart.



2) Remove the SMD resistors R6 and R7.



3) If you plan on running the router with voltages higher than 12VDC (see below), you must upgrade the caps. Use the same capacity, but 25V types instead of the original caps. Observe polarity!



4) Solder some wires to the Pins 4/5 + 7/8 of RJ45 connector for LAN port 1. Run the wires to the indicated positions. Wiring as shown below is for positive (red wire in pic) on brown/brown-white and negative (black wire in pic) on blue/blue-white wires of the ethernet cable and will bypass the power switch. Observe and double-cross-check polarity before connecting to your PoE injector/switch! The power supply circuitry on this router does not have reverse polarity protection.



That's about it.

Note that the power supply chip in this router will accept up to 20VDC. However, if you plan on feeding more than 12VDC, you must upgrade the caps to 25V or higher rated types! I have done my tests with 12VDC supply voltage only.

Also, do NOT ever feed AC power to the router! Doing so will destroy the device!

Oh. Of course, you do all of this at your own risk. Neither I nor dd-wrt.com nor anyone else can be held liable for any whatsoever damage resulting from this mod or your interpretation thereof, etc blah blah blah.

Cheers
gridrun


Last edited by gridrun on Sun Jan 01, 2012 21:38; edited 3 times in total
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Sash
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PostPosted: Mon Dec 26, 2011 18:43    Post subject: Reply with quote
it would be nice if u would add it to the wiki
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gridrun
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Joined: 29 Oct 2011
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PostPosted: Sun Jan 01, 2012 21:33    Post subject: Reply with quote
Sash wrote:
it would be nice if u would add it to the wiki


I would, but the wiki won't let me create an account?
Witty
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Joined: 24 Apr 2012
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PostPosted: Tue Apr 24, 2012 3:17    Post subject: Reply with quote
Thinking of buying one of these and doing this. Just a quick one, what is the purpose of removing the 2 resistors? Do they link your now PoE pins something else in the circuit? Or something ridiculous like down to ground?
Sash
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PostPosted: Sat Apr 28, 2012 21:10    Post subject: Reply with quote
buy a 743 which has already poe support
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gridrun
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Joined: 29 Oct 2011
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PostPosted: Wed Aug 15, 2012 2:20    Post subject: Reply with quote
Witty wrote:
Thinking of buying one of these and doing this. Just a quick one, what is the purpose of removing the 2 resistors? Do they link your now PoE pins something else in the circuit? Or something ridiculous like down to ground?


The resistors go between the wires of each unused pair, instead of just shorting them together. IIRC, that's the standard. Prevents high currents from flowing (by induction).
xnetprox
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Joined: 07 Nov 2012
Posts: 3

PostPosted: Wed Nov 07, 2012 22:04    Post subject: Reply with quote
I've never seen a POE injector that supplied less than 24V, so this mod seems kind of silly.

Why not just use an 802.3af compliant injector and get a 12V POE splitter like this from Panoptic: http://www.panoptictechnology.com/network-smart-adapters/

Much easier solution, and you don't run the risk of destroying your AP Wink
valent
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Joined: 23 Jan 2012
Posts: 24
Location: Osijek, Croatia

PostPosted: Sun Jun 02, 2013 18:43    Post subject: Reply with quote
Awesome guide, thank you!

Has anybody tried making POE mod for 4.x versions of wr741nd ?

UPDATE:
Found this additional info:
http://dev.wlan-si.net/wiki/Routers/TP-LINK/WR741ND#POE
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