WRT54G bad power regulation

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Amall
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PostPosted: Mon Jun 29, 2009 18:04    Post subject: WRT54G bad power regulation Reply with quote
So I have a WRT54G that makes doesn't work, and the fairly loud buzz/hum that comes from the board indicates to me that it has a problem somewhere in power regulation.

I've looked on eBay, and these things aren't worth a ton of money anymore, so I don't want to have to go through herculean efforts to save it. I do know that all the power regulation really does is provide the board with a very stable 3.3 volts.

Would it be possible for me to just find some other stable 3.3 volt supply, and solder it in directly to the output of the onboard power regulation, effectively bypassing the bad onboard regulation? Does anybody know where the actual final output of the onboard regulation is (it's hard for me to test, given that I don't have a working model available)?

It's not the end of the world if I end up completely frying the thing, but it would be awesome if I could find a cheap way to save it.

Thanks!
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redhawk0
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PostPosted: Mon Jun 29, 2009 18:12    Post subject: Re: WRT54G bad power regulation Reply with quote
Amall wrote:
So I have a WRT54G that makes doesn't work, and the fairly loud buzz/hum that comes from the board indicates to me that it has a problem somewhere in power regulation.

I've looked on eBay, and these things aren't worth a ton of money anymore, so I don't want to have to go through herculean efforts to save it. I do know that all the power regulation really does is provide the board with a very stable 3.3 volts.

Would it be possible for me to just find some other stable 3.3 volt supply, and solder it in directly to the output of the onboard power regulation, effectively bypassing the bad onboard regulation? Does anybody know where the actual final output of the onboard regulation is (it's hard for me to test, given that I don't have a working model available)?

It's not the end of the world if I end up completely frying the thing, but it would be awesome if I could find a cheap way to save it.

Thanks!



Here is another option for you....and I use this when I need to...it works very well. Take an old PC power supply. They supply a variety of voltages, but the most useful are the +12 and +5 that normally supply power the the HDD and various other periferals. These powers are typically in the 30-35Amp range for the +5V and in the 8-10Amp range for the 12V...which is more then enough for any router out there.

I have cut the power pack cord off the old router pack and soldered it directly to the appropriate wire pair from the PC supply....the only thing you have to remember is to jumper out the power supply enable wire....do a google search for PC power supply pinouts and you will find the enable wire...just short it to ground and the power supply will work when it is plugged in.

And....it is regulated....for those reading this that have buffalo units running on +3.3V....there is also a +3.3V line on the PC power supply also. (but I don't know the typical amperage off the top of my head)


redhawk

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Amall
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PostPosted: Mon Jun 29, 2009 22:16    Post subject: Reply with quote
Thanks for the tip, I think I have some old pc power supplies lying around somewhere...

The thing is, my existing 12v power supply works fine (and I've tried the 12v power supply from a different WRT54g to confirm). The problem is on the router's board. So, simply cutting the cord and wiring in my new power source won't exactly fix it.

I've heard that all the onboard power regulation does is decrease the voltage to 3.3v and stabilize it (further than the stabilization in the wall wart). I can use an old PSU for my stable 3.3 volts, but I will need to solder it in directly on the router board where the onboard power regulation outputs are. Do you know where that would be? I can post pictures of my board if that would help.
redhawk0
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PostPosted: Tue Jun 30, 2009 0:43    Post subject: Reply with quote
Amall wrote:
Thanks for the tip, I think I have some old pc power supplies lying around somewhere...

The thing is, my existing 12v power supply works fine (and I've tried the 12v power supply from a different WRT54g to confirm). The problem is on the router's board. So, simply cutting the cord and wiring in my new power source won't exactly fix it.

I've heard that all the onboard power regulation does is decrease the voltage to 3.3v and stabilize it (further than the stabilization in the wall wart). I can use an old PSU for my stable 3.3 volts, but I will need to solder it in directly on the router board where the onboard power regulation outputs are. Do you know where that would be? I can post pictures of my board if that would help.


Not right off hand....3.3V may not be the only voltage used on these older 54G units either. They may use the +5V for some chip power...so you might have to solder in dual supplies to make things work.

I've never really probed that thoroughly on a 54G unit to tell you what reduced voltages go where.

redhawk.

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Amall
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Joined: 31 May 2008
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PostPosted: Tue Jun 30, 2009 18:48    Post subject: Reply with quote
Alright, things are getting more complicated and less worth the effort.

So, let's change the topic a bit...anybody know a good use fir a broken wrt54g? I figure I'll save the antennae off it, but what about the rest? Junk?
DHC_DarkShadow
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PostPosted: Sun Jul 19, 2009 18:27    Post subject: Reply with quote
Do you still have the router? What version is it?
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Amall
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PostPosted: Sun Jul 19, 2009 20:15    Post subject: Reply with quote
Yep, I still have it. I'm actually out of town right now, so I can't check the version number.

I did check once, and I remember that it was in the 2.x's. So, either a 2.0, 2.1, 2.2. I'm leaning towards 2.0...

Why? Any thoughts/suggestions?
mixmasta
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PostPosted: Fri Sep 18, 2009 19:04    Post subject: Reply with quote
You could try replacing the capacitors...
Amall
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Joined: 31 May 2008
Posts: 8

PostPosted: Fri Sep 18, 2009 21:14    Post subject: Reply with quote
I checked all the caps pretty thoroughly, and they all looked good and unexploded. However, if I could get replacements for free or cheap I might try that, thanks!
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