Help identifying a component on a wireless router.

[Spork Schivago]

Re: Help identifying a component on a wireless router.

I believe Fzabkar is correct on U40 as the DF- looks up to be this number on this chart he supplied. I do not know how we found the data sheet to the part but he did.

Fzabkar when you say 3 switch mode power supply. Are you saying that there are 3 individual switching power supplies or are you saying that there is one switching power supply with three different mode levels?

I know there's three through-hole transformers on the circuit. Never seen anything like them but they all have the transformer circuit on them. Two of them are the same, one of them is different.

[fzabkar]

Re: Help identifying a component on a wireless router.

At the top left corner, near the DC input socket and on/off switch, are two 100uH coils. Adjacent to each coil is a PWM controller IC. Each coil/IC pair constitutes a step-down buck regulator. These are switchmode supplies that convert the DC input (12V ?) to the lower voltage levels required by the logic.

For example, the Samsung SDRAM typically requires 3.3V or 2.5V, as does the 8-pin EEPROM or SPI flash memory (?) to the right of the crystal. The Broadcom controller probably requires a Vcore supply around 1.2V or so. The 3.3V supply would possibly be its Vio voltage. At the bottom left corner is a third buck regulator.

There will most likely be application circuit examples in the respective datasheets for each PWM IC.

[keeney123]

Re: Help identifying a component on a wireless router.

I believe Fzabkar is correct on U40 as the DF- looks up to be this number on this chart he supplied. I do not know how we found the data sheet to the part but he did.

Fzabkar when you say 3 switch mode power supply. Are you saying that there are 3 individual switching power supplies or are you saying that there is one switching power supply with three different mode levels?

[Spork Schivago]

Re: Help identifying a component on a wireless router.

Wow, thank you! I'll be sure to do that and report back. I really appreciate everything.

[fzabkar]

Re: Help identifying a component on a wireless router.

Thank you fzabkar. Are you 100% sure that's the part? If so, do you mind me asking how you was able to identify it? I tried everything! I even went to a site to look up codes on SMD components.

See https://cdn.badcaps-static.com/pdfs/...0c114d947f.pdf

The "-" in the part marking suggested Richtek.

The top side of the PCB appears to have 3 switchmode supplies. Confirm that there is continuity between the centre pin of U40 and one of the SMPS coils. Also confirm that the left pin is grounded.

If the left pin is grounded, as it appears to be, then the part is highly unlikely to be a transistor. That's because the typical pinout is BCE or GDS, and grounding the B or G would make no sense in this circuit, AFAICT.

[Spork Schivago]

Re: Help identifying a component on a wireless router.

Thank you fzabkar. Are you 100% sure that's the part? If so, do you mind me asking how you was able to identify it? I tried everything! I even went to a site to look up codes on SMD components.

[fzabkar]

Re: Help identifying a component on a wireless router.

See https://cdn.badcaps-static.com/pdfs/...0c114d947f.pdf

RT9809-30PV, Micro-Power Voltage Detector, 3.0V, marking DF-:


Pinout from left to right - Ground, VDD, /Reset

[Spork Schivago]

Re: Help identifying a component on a wireless router.

I would think in this day and age it is a Cmos transistor. I would think you could check it out with a multi-meter. By connecting one of the meter leads to IC ground and they measure the voltage on the 3 leads, with the button of the wi-fi enabled and then disabled. Then if you look at it as a switch I would think two of the points will connect together while the other enables them when the wi-fi is enabled. This maybe a temporary pulse that triggers a latch. So once the latch is trigger high or low depending one the design the microcontroller or microprocessor reads it and runs a go to routine.

Okay, thank you. Tomorrow I'll give it a shot (I don't have access to the router right now). Thanks!!

[Spork Schivago]

Re: Help identifying a component on a wireless router.

Sorry, can't help with a recommendation since my ISP connection is only 5Mbps so 802.11g is more than enough for me. I get hand me down wifi routers from friends who feel they must have the latest wifi speeds.

I can only suggest you get as much DRAM and flash as you can inside the router. Try to stick to a big name brand as it is likely to be supported and look at teardowns to see if the chipsets come from vendors that are open source friendly.

Okay, will do. I was thinking maybe I should look into Cisco. I know they're a bit pricey but it'd be nice to play around with a Cisco router again. Kinda miss that stuff. Last time I checked though, their wifi models where going for around 800$ (just a basic wifi model, nothing fancy). Having a lot of DRAM and flash make sense. We can only get around 50Mbps (it might be 100Mbps now) but we do a good deal of transfers between PCs using ethernet. If I had something like AC, I could maybe do them wirelessly, which would be a big plus.

[Spork Schivago]

Re: Help identifying a component on a wireless router.

that's bullshit, i'v read it before with the DG824GT and seen custom firmware running.
the problem is the WRT people dont want to include anybody's binary blobs in the code release

That could of been the reason, I kind of just glanced over it. It might of been one of those, because this is a fully open source project and this chip requires a binary file, we cannot include it.

[keeney123]

Re: Help identifying a component on a wireless router.

Come tomorrow, I'll try to get nicer pictures. I appreciate it. Do you know what kind of component it might be? I was thinking perhaps a transistor of some sort? I couldn't find any service manuals for the router.

I would think in this day and age it is a Cmos transistor. I would think you could check it out with a multi-meter. By connecting one of the meter leads to IC ground and they measure the voltage on the 3 leads, with the button of the wi-fi enabled and then disabled. Then if you look at it as a switch I would think two of the points will connect together while the other enables them when the wi-fi is enabled. This maybe a temporary pulse that triggers a latch. So once the latch is trigger high or low depending one the design the microcontroller or microprocessor reads it and runs a go to routine.

[retiredcaps]

Re: Help identifying a component on a wireless router.

Could you suggest a good router that supports OpenWRT? I was thinking something that supported Wireless AC and gigabit ethernet ports.

Sorry, can't help with a recommendation since my ISP connection is only 5Mbps so 802.11g is more than enough for me. I get hand me down wifi routers from friends who feel they must have the latest wifi speeds.

I can only suggest you get as much DRAM and flash as you can inside the router. Try to stick to a big name brand as it is likely to be supported and look at teardowns to see if the chipsets come from vendors that are open source friendly.

[stj]

Re: Help identifying a component on a wireless router.

I can do that. However, I went a bit of a different route and I doubt that it will be supported. I looked a the four drivers they used and I researched all of them and that chip. It's a weird chip, the BCM43236. Normally, the drivers load firmware onto the chip. Because this chip doesn't have any memory, they just cannot work. One of the mailing lists went a bit into detail about this. From what I gathered (and I might be wrong), one of the drivers works in tangent with another one and even if they changed their code to support this revision, it would still never work because the other one would never be able to load firmware onto the chip. They said something about Broadcom uses some proprietary way to do something funky with it. I don't know if this is true or not. I might of misunderstood.

that's bullshit, i'v read it before with the DG824GT and seen custom firmware running.
the problem is the WRT people dont want to include anybody's binary blobs in the code release

[Spork Schivago]

Re: Help identifying a component on a wireless router.

I can do that. However, I went a bit of a different route and I doubt that it will be supported. I looked a the four drivers they used and I researched all of them and that chip. It's a weird chip, the BCM43236. Normally, the drivers load firmware onto the chip. Because this chip doesn't have any memory, they just cannot work. One of the mailing lists went a bit into detail about this. From what I gathered (and I might be wrong), one of the drivers works in tangent with another one and even if they changed their code to support this revision, it would still never work because the other one would never be able to load firmware onto the chip. They said something about Broadcom uses some proprietary way to do something funky with it. I don't know if this is true or not. I might of misunderstood.

Does trunk mean latest version? If not, I'll start looking at release candidates.

I also read this Rev 2 router is a bit tricky. If I can get firmware to load, I'll need to use TFTP to undo it to bring it back to factory (if I want wifi working). But the article said I'd need to connect via serial to enable the wired ethernet ports. Thanks for all the help and suggestions.

Could you suggest a good router that supports OpenWRT? I was thinking something that supported Wireless AC and gigabit ethernet ports. I don't really care about USB ports, I can't really see myself using them ever. I'd like concurrent dual-band if I could get it. Might just be time to spend some cash and get something I wouldn't need to replace for a long time.

[retiredcaps]

Re: Help identifying a component on a wireless router.

Have you used Openwrt before?

Yes, I used 14.07 and then updated 15.05 rc1 or rc2. It worked well, no problems, but then I put my old Linksys back into production. The Openwrt router is a backup.

People on kijiji sometime sells newer Linksys routers capable of running openwrt for $5 CDN. I look at the Linksys specs and try to get one with the most amount of flash and DRAM memory so it will likely run openwrt in the future as openwrt, like all software, grows in size.

[retiredcaps]

Re: Help identifying a component on a wireless router.

From my understanding though, the only alternative firmware I could use would provide ethernet, not wireless, because of this unit being rev 2. I had read this on the same site you linked to earlier in the day (I had a similar idea as you did)

WARNING: current trunk version boots but has no WiFi and no Ethernet
Serial console required!

In my search, I only searched for wndr3400 and left out v2. So when I saw v1 and v2 as listed supported, I did not go any further to research/read the caveats, etc. Since I don't have this router, I had no reason to.

You might want to look at the latest release candidate and scan the release notes or changes to see if your router is now supported.

[Spork Schivago]

Re: Help identifying a component on a wireless router.

Seems to me it is being used as a switch to turn on power to 1138 coil. It is hard to tell being I can see the whole circuit clearly going to this coil. It is partially a guess.

Come tomorrow, I'll try to get nicer pictures. I appreciate it. Do you know what kind of component it might be? I was thinking perhaps a transistor of some sort? I couldn't find any service manuals for the router.

[Spork Schivago]

Re: Help identifying a component on a wireless router.

I did not mention DD-WRT only because it hasn't been updated since 2013-04-23. With Tomato, it has not been updated since 2010 June 28. So both are basically abandoned projects for general public usage.

Openwrt has recent and ongoing releases which is important for security fixes. The latest release candidate was dated July 15, 2015.

PS. My wifi router is a Linksys at home running stock Linksys firmware. While I do have a newer wifi router that can run the latest openwrt, I will use this Linksys until it dies. And yes, I have locked down the Linksys router down as best as I reasonably can.

It's nice to know this information. I've always had (and used) a really old wireless G Linksys that couldn't handle any of the other firmwares. This newer one was given to me by my sister. She was having problems with the wifi dropping constantly she said.

Have you used Openwrt before? I'd love to try it. I've always wanted to run a custom firmware on my router...

[Spork Schivago]

Re: Help identifying a component on a wireless router.

That Netgear router can run DD-WRT and Tomato as well.

Are you sure? According to their site (I checked DD-WRT as well earlier), they need a board donation for rev 2. It's listed in their database as a "WIP".

[Spork Schivago]

Re: Help identifying a component on a wireless router.

Before you do any hardware changes, see if your firmware is the latest and greatest from the manufacturer.

I also see that Netgear can run openwrt.

http://wiki.openwrt.org/toh/start?da...*~%5D=wndr3400

You might either or the above?

Sorry for the late reply. I've been a bit busy today, running around like a chicken with my head off! Anyway, I should of explained what I did for trouble shooting first.

First, I checked for a firmware update, there was none, according to Netgear's website. The router is using V1.0.0.38_1.0.61, the latest download I could find on Netgear's site V1.0.0.38_1.0.61.

I did a 30-30-30 reset. When the unit was plugged in, I held down the reset button for 30 seconds. I had someone unplug it after that, kept holding it down for 30 more seconds, had them plug it back in for 30 seconds. This did a factory reset. It brought everything back to the same way it was when it was bought. I then turned the wifi on, using the button on the back, and saw the default SSID. I tried connecting with the default password that was listed on the router, it failed.

I tried connecting via wired, after the recovery, I made sure WIFI was enabled, I disabled the 5GHz bandwidth and changed the SSID and password. I tried connecting again, same as before.

I made sure all antennas where hooked up. It's weird because I can see it with full strength. I just cannot connect wirelessly. Before, I could with no problems. Then one day, it just stopped working. I retired the unit until I had time to work on it (which was supposed to be today). When I ripped it apart, the only thing I could see wrong with the board was that little chip by the button that turns the WIFI on/off. It appeared..I dunno, kinda burntish.

There are pins for a serial connection, J41. It's 6 pins but the pinout is available on the net. From my understanding though, the only alternative firmware I could use would provide ethernet, not wireless, because of this unit being rev 2. I had read this on the same site you linked to earlier in the day (I had a similar idea as you did)

WARNING: current trunk version boots but has no WiFi and no Ethernet
Serial console required!

From reading, the brcmfmac and brcmsmac or whatever it's called will never support this chip because it doesn't have the memory that other chips have or something weird like that. Am I misunderstanding something? Thanks!