wrt150n hardware BUG

Post new topic   Reply to topic    DD-WRT Forum Forum Index -> Hardware DIY / Hardware Mods
Author Message
ciliv
DD-WRT Novice


Joined: 24 Jun 2010
Posts: 1

PostPosted: Thu Jun 24, 2010 15:33    Post subject: wrt150n hardware BUG Reply with quote
I discovered a hardware bug today.
After searching to web, I found out that almost all wrt150n v1, v1.1 have this problem.


http://imgur.com/EXiXS.jpg

red circle from top to bottom:

1. label shows its a 1.8v test point
2. but the measurement shows 2.2v
3. it is a lm117-3.3v compatible ic
4. the input is already 3.3v
5. the resistors are 50ohm and 100ohm


The 2.2v is generated because the Vdo of lm117 is just about 1.1v.
So 3.3v - 1.1v = 2.2v.

According to the label(1.) and the resistors' arrangement it is logical to conclude that the lm117-3.3v is mistakenly used to replace the lm117-adj.

Although it might be because the broad really needs 2.2v to operate, this is a very bad voltage regulating solution.

While the Vdo is not achieved,lm117 will not actually regulate to volatge at all.

I guess this IC is powering the BCM5325 because it is right becide it.
To support my assumption, I teared apart a few other routers/switches that has a Bcm5352.
All of them has a 1.8v regulator beside Bcm5352.

SOLUTION:
1. ignore it for the router has no relibility problem all this time.^.<
2. replace the lm117-3.3 with a lm117-adj
3. replace the lm117-3.3 with a REGULATED 2.2v
power source

Please tell me what you think, I would really appreciated. Thank you
Sponsor
Display posts from previous:    Page 1 of 1
Post new topic   Reply to topic    DD-WRT Forum Forum Index -> Hardware DIY / Hardware Mods All times are GMT

Navigation

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum