[time-nuts] 5071A with ATTENTION flashing

Tom Van Baak tvb at LeapSecond.com
Thu Nov 3 12:37:16 EDT 2016

Hi Li,

The "Low cs signal with max Emult" is the classic error indicating it's out of gas. That's a bad sign. But the "9.2GHz PLL test 10.3v" is something else. So maybe there's hope? Or maybe you have two big problems instead of one. Rick might know.

For additional information, connect a PC to the serial port and capture the diagnostic information. Right after power up, press TOP -> CONFIG -> LOG -> SERVICE to set the unit into verbose diagnostic mode. You should see lines print every now and then as it undergoes self test and calibration.

You can also press TOP -> INFO -> PRINT to get a nicely formatted summary. Or TOP -> LOG -> PRINT to get the entire log history. That sometimes has lots of clues. The advantage of using the serial port is you get a permanent record of all this information. Viewing all this by the LCD screen can be tedious.

There's more information in 05071-90040, the 5071A Assembly-Level Service Manual, copies of which are on the web. Also 05071-90041, Operating and Programming Manual.


----- Original Message ----- 
From: "Li Ang" <379998 at qq.com>
To: "time-nuts" <time-nuts at febo.com>
Sent: Thursday, November 03, 2016 8:10 AM
Subject: [time-nuts] 5071A with ATTENTION flashing

> Hi
>  Today I met one HP 5071A with option 001 at one secondhand equipment company. This one can not enter CONTINUOUS OPERATION status, the ATTENTION led flashes. 
>  There is a "Low cs signal with max Emult" error in the log. I have run the self-test, and it stopped at "9.2GHz PLL test 10.3v".  I can only remember the the pump current was 0.8uA or less, C-filed was about 12mA. 
>   The seller is asking for about 4000$, I am wondering if it's repairable. Since it is a "HP" branded 5071A with 001 option,  I do not know if the Cs tube is dying or not, according to the two current values? 
>   How do I know one 5071A/5061/5062 is dying or is still in good health by the readings?
> Thanks
> de BI7LNQ

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