ZD1200 Solid Green lights but dead - 3 different instances this week

[tommy_galuszka]

So I am a tech for a system integration company that primarily uses Ruckus in all of our installs.  I have had 3 calls this week about wifi down and each of them was the same result.  ZD1200 appears to have completely died.  All lights are solid green, even on a fresh reboot (never see the red status light at all even while booting).  None of the units respond to ping, ssh, console...nothing.  I found it very odd the first time I saw it since I have never seen this issue in 15 years of servicing, but to see it 3 times now this week has me very concerned.  Not sure what to do next or even what to tell the clients?  Do I have 3 randomly bricked ZD1200s in a week?

[itdept_head_me]

They don't want this discussed in public.

all behind the scenes....

it's the flash.

re-flashing re-inits the storage & marks the bad blocks, but it is a fools game.

Eventually like all flash products it will cascade & lead to full failure.

[chris_borderit]

Should be easy to prove with one working and one dead?

It should at least boot with a good CF in it? Even if they are locked to the board, which I would doubt.

Have you done any investigation as you have access to units? 

Read the flash and checked for bad blocks? Found any issues?

Swapped flash?

I do agree flash would become a problem, my symptoms don't specifically indicate that.

Monitored CPU activity?

Does the VGA out normally show a boot screen like bios or so before loading OS?

There is normally a beep that sounds like a POST beep, perhaps you can see when that normally occurs on a good unit, with a monitor and or SSH or?

Oh, you said you did some CF research, yet not clear on result of replacing flash and why it failed again.

Curious

[chris_borderit]

I would think the battery is another key failure point?

[eizens_putnins]

I have seen ZD1200 with died flash, usually it happened after or as a direct result of power loss, but sometimes flash is broken without obvious reason. It should be not a critical issue, as normally ZD1200 should be used in Smart redundancy configuration, and ZD1200 has life-time warranty, so you need just RMA it.

You can make sure taht it is flash issue, connecting by some terminal program to ZD1200 serial port. You'll see obvious errors during boot process.

In some cases, after power loss, flash is OK, but filesystem is damaged, in this case ZD can be recovered, reformatting flash and uploading new image to it.  But if you see errors reading flash, don'r waste time and go directly to RMA option... 

By the way, when WiFi network is down because of ZD1200 fault, it means that improper design was used -- it must be clear that if system is used with just 1x ZD1200, it becomes the single point of failure, as all WLANs are down, if it fails. As difference in price for system with redundant ZD1200 configuration with at least 10 APs is very small, it can't be anything else as a wrong (or uninformed) decision.  

In many cases customers think that price for redundant ZD1200 pair is double, which is not true -- from version 9 licenses on both ZD are summarized, and price for support for redundant ZD1200 is much lower. So for redundant system with 10 APs you need second ZD1200, but as you don't need additional 5 licenses for the first ZD, and support for redundant ZD is really cheap, there is just a really small price difference for redundant solution, and it should be always used.

Anyway, we almost stopped to use ZD1200 in our projects 5 years ago -- small projects can be even better done using Unleashed or cloud, and anything bigger than few APs is best served by vSZ.

[eizens_putnins]

And I don't think ZD1200 has RTC battery. Never replaced it at least...