Dead Advantest R3131? Not yet!

[nctnico]

A quick note: My Advantest R3131 spectrum analyser threw me a nasty surprise today. Yesterday it already started with an RTC error but no problems. Today it wouldn't start at all. It just showed a half screen with some garbled text.  Not a good sign!
So I opened it up and checked the RTC battery. Completely flat! Fortunately I had a litium battery lying around so I put that in but no go. Still garbled text and no response to any keys. Switched it off a couple of times, left it on for a while but still no go  Just as I need it it bails out on me! I pulled out the CPU board again but it has no EPROMs/FLASH to reseat or anything in sockets. Then I noticed a small push button in the bottom left corner (seen from the rear of the unit). I switched it on again, pressed the button and.... it works again!  Appearantly that button is some kind of reset-everything button to re-initialise the RTC data. I ran the self calibration and everything passed just fine.

[tautech]

 
Nice catch.
Was this reset mentioned in the manual?

[nctnico]

Nope. I checked the user and maintenance manual but couldn't find. I don't rule out I overlooked it though.

[crispy_tofu]

Good catch. 

Today it wouldn't start at all. It just showed a half screen with some garbled text.  Not a good sign!

Just a question, how would a flat RTC battery cause the screen to go garbled?

[nctnico]

Probably some software bug which doesn't recognise the data stored in the battery backuped RAM. So the software crashes with all kinds of erratic behaviour. Pretty bad engineering! Perhaps they didn't bother because they have the 'recovery switch'.