Also, the large count of failing NAND blocks is not symptomatic of the capacitor issue. On boards with failing caps, they will just start to randomly crash/halt, and as the caps continue to lose integrity, it will happen with increasing frequency, and eventually the boards will just fail to boot up entirely.
I *do* recall that there was a particular NAND chip that MikroTik started using in later batches of 4xx boards that people reported high failure rates of. I believe MT eventually worked around the issue in software. I think there was even a large wiki article about it; I'll see if I can dig it up. On the boards that have "failed", have you tried, out of curiosity, to format the NAND in the bootloader and re-Netinstall? -- Nathan -----Original Message----- From: mikrotik-users-boun...@wispa.org [mailto:mikrotik-users-boun...@wispa.org] On Behalf Of Scott Lambert via Mikrotik-users Sent: Monday, October 17, 2016 4:22 PM To: TJ Trout Cc: Mikrotik Users Subject: Re: [Mikrotik Users] Is anyone else losing RB493Gs? On Mon, Oct 17, 2016 at 03:20:19PM -0700, TJ Trout wrote: > Are you sure it's not capacitor plague? Easy to fix with a smd rework > station I don't see any leakage or doming of the three largeish electrolytic capacitors on each board. I am not even slightly tempted to attempt to test all of the SM caps. But I might try one or two if you have suspects. No SMD rework station either. I'm actually quite happy to have the 4xx series MTU limitations leave the network. I just don't like spending more money for similar performance / port count before we have to. The affected serial numbers cover a fairly wide range. I was hoping to use age as a predictor, but the dead units are scattered from 25E0017443A5 to 25E0017A1420. Assuming the numbers are actually sequential, they are seperated by 381,051 units. Maybe that's one production batch? I doubt it. Off topic, I have one other RB493G in the dead drawer with a SN of 37970127C53D which was killed by lightning. I'll bet that was a different batch. :-) > On Oct 17, 2016 12:55 PM, "Scott Lambert via Mikrotik-users" > <mikrotik-users@wispa.org> wrote: > > > We deployed a lot of RB493Gs a few years back. They are starting show > > 80 to 95% bad blocks on their flash storage. I've been losing two to > > three per month for a few months now. > > > > The initial symptom is the automated ssh process which gathers IP pool > > utilization to feed MRTG starts reporting that it cannot log in. When I > > go to look at the problem, all users are gone and I can only log in as > > admin with no password. They do not survive a reboot. But so far, if I > > don't reboot them, they keep doing what they were supposed to do. They > > just allow anyone to login with the default username and password. > > > > So far, I've not lost any RB450Gs, but beings from the same family, I > > half expect them to start going. I have many fewer of those. > > > > I'm not upset about losing these things after 3 to 5 years. I am curious > > if others are seeing the same thing happen on your networks. > > > > If others have left their RB493Gs on older firmware and are not seeing > > issues, maybe it's a 6.30+ issue on RB493G bug? Most of my have been > > brought up to 6.30+ to work around some PPPoE + mangle/queue tree > > issues. (The MSS mangle rules don't get inserted before rule 0 leading > > to PathMTU issues.) > > > > If it is happening to others, maybe I need to order 16 to 21 > > replacements and do some preventative swaps. > > > > "RouterOS RB493G","6.34.6" > > "RouterOS RB493G","6.32.3" > > "RouterOS RB493G","6.34.4" > > "RouterOS RB493G","6.7" > > "RouterOS RB493G","6.32.3" > > "RouterOS RB493G","6.34.6" > > "RouterOS RB493G","6.34.6" > > "RouterOS RB493G","6.30.4" > > "RouterOS RB493G","6.34.4" > > "RouterOS RB493G","6.30.4" > > "RouterOS RB493G","6.32.3" > > "RouterOS RB493G","6.18" > > "RouterOS RB493G","6.18" > > "RouterOS RB493G","6.7" > > "RouterOS RB493G","6.18" > > "RouterOS RB493G","6.30.4" > > > > "RouterOS RB450G","6.7" > > "RouterOS RB450G","6.32.3" > > "RouterOS RB450G","6.32.3" > > "RouterOS RB450G","6.34.6" > > "RouterOS RB450G","6.34.6" > > "RouterOS RB450G","6.27" > > "RouterOS RB450G","6.34.3" > > > > -- > > Scott Lambert KC5MLE Unix SysAdmin > > lamb...@lambertfam.org > > _______________________________________________ > > Mikrotik-users mailing list > > Mikrotik-users@wispa.org > > http://lists.wispa.org/mailman/listinfo/mikrotik-users > > -- Scott Lambert KC5MLE Unix SysAdmin lamb...@lambertfam.org _______________________________________________ Mikrotik-users mailing list Mikrotik-users@wispa.org http://lists.wispa.org/mailman/listinfo/mikrotik-users _______________________________________________ Mikrotik-users mailing list Mikrotik-users@wispa.org http://lists.wispa.org/mailman/listinfo/mikrotik-users