Hi,
some more things to check:
1) in case you can still lock with a strong lock solvent like D2O, please post
a screenshot of "Lock Scan". In case the lock XCVR board has developed an
issue there may be a vertical glitch visible at the first data point.
2) try to insert a D2O (test) sample and click "Auto Lock". Do you get a
"S/N too low, z0 not set" error message (which means no deuterium peak could
be found) or a message like "Z0 set to xyz value"? If the latter, which value
does it (try to) set z0 to? If the value is larger than 32768 (or smaller
than -32768) then you should reset the lock frequency like Ronald suggested
(so you have to change the lock frequency in order to change the base
frequency). Typically the change is around 1.5 kHz, so 0.0015 MHz, so subtract
0.0015 from your current lock frequency in Edit - System Settings - System
Config. Run "su" and try "Auto Lock" again.
3) if Auto Lock does find a resonance but the lock signal is still (very)
weak, try to optimize the lock phase (on the Lock panel) by starting "Lock
Scan" and change the lock phase (try in steps of 10 degrees). Could be that
after a console power cycle or mains power failure, the lock phase may have
changed. Typical values are around 0, 90, 180 or 270 degrees.
Best regards
Bert
> Am 04.11.2025 um 16:57 schrieb Jessi Baughman via groups.io:
>
> Hi Stephen,
>
> A good place to start would be to measure the voltages of the main power
> supply and ensure they are all above marked values. In particular, look at
> the 5V as that controls shim blanking. If at or under 5V, then when you run,
> you'll be effectively running with reg0 shims. If you're not seeing any
> signal when you run a spectrum, you may also need to check the voltages of
> the RF front end, which should be +7, +18, and -18V. The 7V sits on top and
> is prone to burn out.
>
> --
>
> Jessi Baughman
> Scientist Staff, Analytical Science * Akron
> The Goodyear Tire & Rubber Company
> 142 Goodyear Blvd, Akron, OH 44305
>
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Received on Tue Nov 04 2025 - 16:03:22 MST