linksys router went unstable today with 3 years uptime.cause was rather interesting.

[kc8adu]

its a wrt54g with dd-wrt.
has never given the least little bit of trouble.
network and wifi started dropping out followed by a reboot.
coincidentally my line voltage was going low.
low enough to trip avr on one of my ups and making another switch to battery every few minutes.
then the router started acting up.
at 99.5v ac in the wallwart was giving only 7.9v under load.
not enough headroom for the router.
it was an old iron wallwart that was original.
the router has polys and a 2200@16 on the dc in.
i suspect the cap in the walwart is long gone and the one i added 5 years ago allowed it to get by till the line voltage dropped.
about the time i noticed this i also noticed the internet stayed up while the ups was on battery.
so these things get marginal over time.
i recapped a switchmode wallwart and its stable again.
the line got to 97v and the ups stayed in battery till whatever was causing this was corrected at the substation.
a friend across town had problems with a pc rebooting.his line was 95v!
still expecting the substation to go boom like it has several times over the years.
i hear arcing noise in my hf radio.

[retiredcaps]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

its a wrt54g with dd-wrt.

I retired my wrt54gs since dd-wrt hasn't been updated on them for years.

I keep them around in case I need to run bridge functionality or something, but my routers that I get for free from my local kijiji all are capable of running lede. I'm running 17.01.1 (latest version since April 2107).

Sad that the modern router needs 8MB flash and 32 to 64MB DRAM to run now.

My running one has 4MB flash and 32MB DRAM. Others are 8/32 or 8/64 for future versions of lede once it breaks the 4MB flash barrier.

[stj]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

if it's serial flash - put a bigger chip in.
i'v done that in the past by putting 4 and then 8meg flash into routers that had 2meg

[kc8adu]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

iirc i upgraded this ones ram.
there is 1 cve for these and i applied a fix.
otherwise it will get run till it dies.
and the cap was indeed shot in the wallwart.
its a telecon 1000@16 that is suspiciously small for the stated value.
as warm as the wallwart ran its surprising it held out this long.but as stated earlier there is a 2200@16 at the dc input vs the 220 it came with.
the cap in the wallwart may have been bad years ago.
btw i added chipset heatsinks to the soc and ethernet chips when i modded it.
i suspect it will have to take a lightning strike to do it in!

[Per Hansson]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

I have a WRT54GS that was acting up two days ago.
Packetloss on the WiFi, reboot did not help.
Thought it might be the wallwart after remembering your thread.
Because I had also recapped the router with Rubycons years ago.
Cracked it open (without destroying anything, yay!).
There was a Fulltec FRA 2200uF 25v cap rated 85°C
But it actually measured good after all these years.
Replaced it with a Rubycon anyway since I had the wallwart open.
Still have not figured out what the cause of the packetloss was...

[stj]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

capacitance +esr o.k.
but you couldnt check the ripple current.

scoping it while running may have shown something interesting.

[Per Hansson]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

I did scope it while running.
There was no significant difference before and after.
About 1v sawtooth ripple but it's normal with a linear AC > DC wallwart.
I.e. something like this: https://en.wikipedia.org/wiki/Ripple...background.svg

[stj]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

any ripple is a design failure - the cap should have been better.

[Per Hansson]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

I retired my wrt54gs since dd-wrt hasn't been updated on them for years.

Actually it has, you can find it here under broadcom:
https://download1.dd-wrt.com/dd-wrtv...ds/betas/2017/

Build 32170 worked well, the ones after had problems where you can't get into the GUI, so they become effectively bricked unless you can flash via serial console...

You don't need to flash the device specific firmware, the generic one works fine. (Just check the size).
It's only if you are flashing from the CFE or webinterface of the original firmware that you need the device specific firmware.
I flashed this on a WRT54GL: ftp://ftp.dd-wrt.com/betas/2017/06-0...al_generic.bin

I keep them around in case I need to run bridge functionality or something, but my routers that I get for free from my local kijiji all are capable of running lede. I'm running 17.01.1 (latest version since April 2107).

Sad that the modern router needs 8MB flash and 32 to 64MB DRAM to run now.

My running one has 4MB flash and 32MB DRAM. Others are 8/32 or 8/64 for future versions of lede once it breaks the 4MB flash barrier.

I tried LEDE on my WRT54GS routers, it works but there where some issues with the LED's that I posted to the bugtracker.
https://www.badcaps.net/forum/showth...544#post759544

[Spork Schivago]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

its a wrt54g with dd-wrt.
has never given the least little bit of trouble.
network and wifi started dropping out followed by a reboot.
coincidentally my line voltage was going low.
low enough to trip avr on one of my ups and making another switch to battery every few minutes.
then the router started acting up.
at 99.5v ac in the wallwart was giving only 7.9v under load.
not enough headroom for the router.
it was an old iron wallwart that was original.
the router has polys and a 2200@16 on the dc in.
i suspect the cap in the walwart is long gone and the one i added 5 years ago allowed it to get by till the line voltage dropped.
about the time i noticed this i also noticed the internet stayed up while the ups was on battery.
so these things get marginal over time.
i recapped a switchmode wallwart and its stable again.
the line got to 97v and the ups stayed in battery till whatever was causing this was corrected at the substation.
a friend across town had problems with a pc rebooting.his line was 95v!
still expecting the substation to go boom like it has several times over the years.
i hear arcing noise in my hf radio.

What do you mean by substation? Also, how were you checking the line voltage? Just curious, so I can do stuff like that when I experience problems.

[Spork Schivago]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

I retired my wrt54gs since dd-wrt hasn't been updated on them for years.

I keep them around in case I need to run bridge functionality or something, but my routers that I get for free from my local kijiji all are capable of running lede. I'm running 17.01.1 (latest version since April 2107).

Sad that the modern router needs 8MB flash and 32 to 64MB DRAM to run now.

My running one has 4MB flash and 32MB DRAM. Others are 8/32 or 8/64 for future versions of lede once it breaks the 4MB flash barrier.

Is the reason dd-wrt hasn't been updated for the wrt54gs in years because of the smaller flash size and lower amount of RAM? If not, if there's a newer version of dd-wrt available, I might be able to port the code for the wrt54gs over to the newer version.

I'm doing that with OpenWRT. It doesn't support the Vizio XWR100 that I have. I'm trying to modify OpenWRT to support it. It's going good. I got it to compile with just the default options, but I tried adding some features, like USB-HID stuff, so a person could plug a keyboard into the USB port and type directly on the router, if they wanted to. I've added some modules for various filesystems, so they can plug a thumb drive or external hard drive into the USB port and store stuff there. But with these options (just the USB-HID stuff), the build currently fails. I gotta see why. I'm working on it though.

[Per Hansson]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

What do you mean by substation?

Transformer station, the transformer that takes the high voltage and brings it down to 400v line to line here in Sweden for example.

Also, how were you checking the line voltage? Just curious, so I can do stuff like that when I experience problems.

You of course just stick a meter of sufficient quality into an available power jack, line to neutral in this case.

Is the reason dd-wrt hasn't been updated for the wrt54gs in years because of the smaller flash size and lower amount of RAM? If not, if there's a newer version of dd-wrt available, I might be able to port the code for the wrt54gs over to the newer version.

Did you read my post directly before yours?

[Spork Schivago]

Re: linksys router went unstable today with 3 years uptime.cause was rather interesti

Transformer station, the transformer that takes the high voltage and brings it down to 400v line to line here in Sweden for example.

You of course just stick a meter of sufficient quality into an available power jack, line to neutral in this case.

I understand. I just didn't understand the terminology. The substation stuff confused me. I know what the transformers are and we even had one at the old place blow. When it went out, it was around 2:00AM and I was outside smoking, back when I smoked cigarettes. It made an extremely loud BANG! like someone shooting a shotgun. I used my wife's phone to call the electric company and told them what I had heard. They wanted to know if it sounded like it came from up the road or down. I said it was right by the lower driveway, where the transformer is. They surprisingly had it fixed within a couple hours. A truck was already driving by before I hung up, some they must be able to tell when something like this happens I guess. They had some sort of spot light and was shinning it at the lines. After I hung up, the truck came back and started shinning it by the lower driveway. They saw the transformer, and had some bucket type device, but I went to bed by then. The lights were all on and around two hours later, we got woke up to a stereo blaring.

Did you read my post directly before yours?

Yes, I did read it. But I read his first post and responded. Then I read the read of the posts. I think I need to get in the habit of reading the entire thread before making posts. Sorry about that.