Yto Loop Errors (331); 600 Mhz Reference Loop (333) - HP 8560A Service Manual

324 FREQ ACC
for the fine adjust DACs to bring MAINSENSE to exactly 0 volts.
325 FREQ ACC
fine adjust DAC cannot bring MAINSENSE to 0 volts.
326 FREQ ACC
bring MAINSENSE to 0 volts. ERR 326 is set if the fine adjust DAC
value is set to less than 5 or greater than 250.
327 OFF UNLK
reference. The 10 MHz reference should measure greater than -7 dBm
at A155303. The ADC measures OFFSENSE at the beginning of each
sweep and, if the voltage is outside certain limits, the offset oscillator
pretune DAC is adjusted to bring OFFSENSE within the proper
range. ERR 327 is set if this cannot be accomplished.
328 FREQ ACC Roller fine adjust DAC sensitivity less than or equal to 0. During the
LO adjust routine, the fine adjust DAC is set to two different values
and the MAINSENSE voltage is measured at each setting. ERR 328
is set if the difference between these voltages is 0 or negative. This is
typically the result of the main roller loop's being unlocked.
329 FREQ ACC Roller coarse adjust DAC sensitivity less than or equal to 0. During
the LO adjust routine, the coarse adjust DAC is set to two different
values and the MAINSENSE voltage is measured at each setting. ERR
329 is set if the difference between these voltages is 0 or negative. This
is typically the result of the main roller loop's being unlocked.

YTO Loop Errors (331)

This error rarely occurs but is usually indicative of a digital hardware
failure.
331 FREQ ACC Invalid YTO frequency. Firmware attempted to set the YTO to a
frequency outside the range of the YTO (2.95 to 6.8107 GHz). Suspect
a digital hardware problem, such as a bad RAM on the A2 Controller
assembly. Contact the factory.

600 MHz Reference Loop (333)

This error requires troubleshooting the Al4 Frequency Control
assembly (Synthesizer Section) or the ADC circuits.
333 600 UNLK The 600 MHz Reference Oscillator PLL is unlocked. If error codes
302, 303, 304, 327 or 499 are also present, suspect the 10 MHz
Reference, the A21 OCXO, or the TCXO on Option 103, or the Al5
RF assembly. ERR 333 is set if L03ERR is outside of its prescribed
limits.
Unable to adjust MAINSENSE 1 c ose to 0 volts using the coarse adjust
DAC. The coarse adjust and fine adjust DAC are used together to set
MAINSENSE to 0 volts with the loop opened. ERR 324 is set if the
coarse adjust DAC cannot bring MAINSENSE close enough to 0 volts
Unable to adjust MAINSENSE to 0 volts using the fine adjust DAC.
The coarse adjust and fine adjust DAC are used together to set
MAINSENSE to 0 volts with the loop opened. ERR 325 is set if the
Fine adjust DAC near end of range. The fine adjust DAC is set to
Offset roller oscillator PLL is unlocked. May indicate loss of 10 MHz
General Troubleshooting 6-21