3
2
1
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
App
Index
17.1 Troubleshooting
• For the appropriate corrective actions when an message is shown on the display, see
section 17.2.
• If servicing is necessary, or if the instrument is not operating correctly after performing
the corrective actions described below, contact your nearest YOKOGAWA dealer.
Problem
Probable Cause
Corrective Action
Reference Section
The power does not turn ON.
Using a power supply
outside the ratings.
Use a correct power supply.
3.3
The GS820 does not power
up correctly.
The setup file is corrupt.
If the GS820 still does not power up correctly
even after cycling the power, turn ON the
power while holding down the ESC key and
+/− key. The GS820 powers up by formatting
the GS820ROM.
If the GS820 still does not power up correctly,
servicing is required.
—
Nothing is displayed.
The display is turned OFF.
If the SHIFT key is blinking, the display is
turned OFF. Press any key or turn the rotary
knob.
11.4
Keys do not work.
The GS820 is in remote
mode.
The GS820 is in remote mode when the
remote indicator is illuminated. Press the
SHIFT (LOCAL) key to enter the LOCAL
mode.
—
The keys are locked.
If the KEY LOCK indicator is illuminated, the
keys are locked. Press the SHIFT + • (KEY
LOCK) key to clear the key lock.
11.8
Other causes.
If a certain key does not work, it may be due
to a bad connection. Perform a key test of
the self-test. If there are keys that do not
operate, servicing is required.
17.3
The USB storage function
does not work.
The GS820ROM is corrupt.
If only the GS820RAM appears on your PC,
the GS820ROM may be corrupt.
Format the storage.
4.6
The drive assignment on the
PC overlaps with another
the drive.
Use a management tool on the PC and
change drive letter so that it does not overlap
with other drives.
—
The PC does not support
the
USB mass storage
class.
The USB storage function is valid on
Windows PCs. Check that the GS820 is
detected in Device Manager.
—
The file written from the PC
cannot be viewed on the
GS820.
The file is written only to the
PC cache memory.
Carry out “safely remove USB Mass Storage
Device” on the PC to make sure that the
cache is written to the storage device.
—
The source level or
measured value is strange.
Insufficient warm-up.
Warm up the GS820 for 60 minutes after
turning ON the power.
—
The ambient temperature is
fluctuating.
Use the GS820 in a stable environment
within the specification range.
—
The signal contains noise.
Use the GS820 in an environment free of
noise. Exercise caution especially when
handling minute voltage or current.
3.5
The GS820 is oscillating.
Check whether the load is within the
allowable range. Use twisted-pair wires for
wiring.
3.5
The connection is
inappropriate.
In the case of a four-terminal connection,
check that the connection is correct.
Note that in the case of a two-terminal
connection, the GS820 receives effects from
the lead wire resistance or contact resistance
when the output current is large.
3.5
Chapter 17 Troubleshooting and Maintenance
17-1
IM 765601-01E
Troubleshooting and Maintenance