Help with linksys adsl router innards

K

K3NS31

Expert Member
Joined
Jul 19, 2009
Messages
4,106
Reaction score
449
Hey guys, need some help please.
Been having some issues with my Linksys adsl / wifi router, so I decided to open it up.
What I need is more info on what's going on inside, so I've taken some pics.
btw, router is a Linksys WAG120N

all

This one is the main board.
My questions are: What's the big, square silver thing (red arrow)? It doesn't look like a chip, and the thing with the heatsink above it is probably the main processor. Could it be the wireless n antenna? (device is supposed to do wireless n).
I presume the 2 parts marked by the green arrows are the antenna and the antenna attach point? This appears to be the only antenna - is that enough for wireless G and Wireless N? (It can only do 1 at a time, so maybe that's why only 1 antenna?)
Here's a better pic, but without the arrows:
all



all

This is the back of the board, where you can see the square silver thing from the other pic has a smaller silver square piece on the back.

all

Now this is a plastic sheet under the board. What is it's purpose? Is it to conduct heat (the ventilation holes are below it). If so, it doesn't work very well as the device runs HOT.
Or maybe it's an anti-static thingy. In which case, it's blocking the cooling holes, can I remove it? Or at least make some holes in it?

Thanks for the help.
 
Last edited:
The big silver square is the shielding cover on the wireless components of the router. Yip, the green arrows are the antenna connector and external antenna, respectively.

Unfortunately I don't know what the plastic sheet is for.
 
Ok, so that's the actual wireless card? That makes sense. Also explains why it gets so hot.
 
It would be more helpful if you provided clear pictures of the lettering on and around the integrated circuits.
 
The shield on the bottom is an RF/EMC shield designed to screen the board from incoming or outgoing EMC radiation. So no, I would not modify it if I were you.
 
Last edited:
Last edited:
kayvee said:
The shield on the bottom is an RF/EMC shield designed to screen the board from incoming or outgoing EMC radiation. So no, I would not modify it if I were you.
Click to expand...

Thanks, that's the kinda thing I needed to know.
Any opinions on disconnecting the internal antenna and connecting an external? Looks like it should be fairly straight-forward? (Poor signal strength is my other issue.)


Sent from my E10i using MyBroadband Android App
 
Yotch said:
Maybe you could either place the unit on a notebook cooler, use a USB fan or install one inside the case if you are more adventurous. Mantech has fans right down to 17mmX17mmX8mm etc.
http://www.zapsonline.com/39524-isonic-nc2-3-blue-led-fans-notebook-cooler-siis-nc2.html
http://rebeltech.co.za/index.php?main_page=product_info&cPath=1_83&products_id=5610
http://rebeltech.co.za/index.php?main_page=product_info&cPath=1_96&products_id=5621
http://www.mantech.co.za/Stock.aspx?Query=fanand
Click to expand...


Thanks for the links, will check those links when i'm back at my pc. I was thinking external fan myself, but then wouldn't I need a way to "duct" the air to the vents?

Sent from my E10i using MyBroadband Android App
 
I've never seen that router so I don't know where the vents are but I was thinking that if you blow air in from underneath, at least some of it would get into the case.

The smallest relatively cheap general purpose fan that might fit inside the case is probably a 40X40X10mm or a 30X30X10mm but you would have to construct a simple box of the same size to test whether or not it would fit before buying one. You would probably need to solder leads to the two pins on the DC power jack (12V?) underneath the PCB. This would presumably void the warranty though.
http://www.mantech.co.za/ProductInfo.aspx?Item=70M0746
http://www.mantech.co.za/ProductInfo.aspx?Item=70M0728
http://www.zapsonline.com/43596-jetart-black-cpu-and-chipset-40mm-fan-tvdf4010.html

If you decide to use an external fan you could purchase both a male and female DC power jack/socket of the same dimensions as the one on the router's current power pack. By making a simple extension cable, the two fan power wires could also be connected to the same power pack via the two terminals of the inline female DC power jack. If you choose to use a 5V USB fan then you may need to include a 1W series resistance of 50~100 Ohms to reduce the voltage to the fan. You would need to take in the router's power pack to get the correct jack/socket as there are several different lengths (9, 14mm etc.) and diameters etc. Make sure that the polarity of the supply to the router is not changed or you could damage it. Alternatively you would need a second power supply to drive the fan as there appears to be no USB port on that router.
http://www.mantech.co.za/ProductInfo.aspx?Item=82M0266
http://www.mantech.co.za/ProductInfo.aspx?Item=K311V.
 
Last edited:
Wow, thanks for all that info Yotch.

I ended up getting a laptop stand / cooler similar to the one you suggested here: http://www.zapsonline.com/39524-isonic-nc2-3-blue-led-fans-notebook-cooler-siis-nc2.html
but the one I got only has 2 fans.
It uses USB power, so now I'm looking for one of those USB to AC power adapters like you get with the new cell phones or ipods. Which is turning out to be quite difficult to find.

Then next step is to add an external antenna.
 
The cheapest and neatest way to power your fan is to make up an extension cable to connect the fan to the router's supply but it will involve soldering ~10 joints as mentioned above.

The cheapest source of those USB adapters is DealExtreme if you have a PayPal account. Those prices incude shipping to SA. They sell hundreds of different types so just look carefully for one that will fit an SA plug socket.
http://www.dealextreme.com/p/usb-power-adapter-charger-110-250v-eu-plug-47343
http://www.dealextreme.com/p/usb-power-adapter-charger-white-100-240v-eu-plug-29415#open full view
You can get the same things on Bidorbuy but not as cheaply ...
http://www.bidorbuy.co.za/item/3620...Power_Supply_Adapter_for_MP3_MP4_PDA_GPS.html
http://www.bidorbuy.co.za/item/36120229/iPOD_iPHONE_3in1_USB_TRAVEL_SYNC_POWER_PACK_BRAND_NEW.html
Ellies (www.ellies.co.za) sell several different types - BPAC6 might be available at a premium at Incredible Connection etc. - phone Ellies to get an idea of the price
http://www.ellies.co.za/index.php?id=1584
http://www.dionwired.co.za/ELLIES-USB-AC-charger-BPAC6-478098.aspx?mode=review
Expansys has several power packs on special at the moment but you would need to change the plug to a female USB
http://www.expansys.co.za/hp-ipaq-us-power-adapter-100905/
http://www.expansys.co.za/expansys-ipaq-travel-charger-base-108526/
This is a 12V power pack so you would need to add a resistor ...
http://www.expansys.co.za/premier-systems-eu-power-supply-for-speaker-phone-desk-station-112373/

Another option might be a mains powered USB hub. I think that the power should be available even if you don't connect the hub to a USB port. You can often find these for ~R50 on BoB. You might be able to use it for something else at a later stage ...
http://www.bidorbuy.co.za/item/35688329/BELKIN_4_PORT_USB_Plus_HI_SPEED_HUB_BRAND_NEW.html
http://www.bidorbuy.co.za/item/3541...USB_HUB_Adapter_for_Laptops_and_desktops.html
 
Last edited:
Awesome.
Think I'm gonna try Ellies first. Hadn't thought of them. The problem with those online stores is that for such small / cheap items, you end up paying more for shipping than the actual product.
They should also have those BNC type connectors for the antenna, right?

I had decided to buy a powered USB hub as a 'last resort'. Can get them for very reasonable prices nowadays.

If I were to go with your idea above and modifiy my router's power connector, where would I buy those resistors and stuff? Also Ellies?

Thanks again for the help
 
I think that Ellies used to sell a few components. Just phone them to check - maybe they can suggest where to get that USB supply closer to you. 1W Resistors should only cost about 10c. Just look on the USB fans to get either the current or the power. Calculate the resistance of the fan using R = V/I , where V=5V and I = fan current. If you are going to use a 12V supply to power the fan then then calculate the resistance using x = 7R/5 where R = fan resistance calculated above i.e. if the added resistance is equal to the fan resistance then the USB fan will receive half of the supply voltage i.e. 6V so the added resistance should be slightly larger to drop the voltage to 5V. If you put an internal fan inside the router you might be able to just push the wires through one of the air vents and avoid soldering to the PCB. I think that Mantech would be your best bet for connectors - they have a huge range of components. Just take along the power pack and antenna etc.

PS If your cooler has two fans then I = fan current = 2X single fan current. Choose a resistor which is a bit larger than what you have calculated to reduce the fan speed/noise.

If you want to add a heatsink to any of the other chips Mantech has a 28x28x8mm unit including adhesive tape for around R6 (looks very similar to the one that's already installed). The product code is SL7122.
 
Last edited:
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X