Power Supply Problem - LeCroy WaveSurfer 400 Series Service Manual

6.10.4 Power Supply Problem

P
RESS THE FRONT
PANEL POWER SWITCH
A
RE THE
FANS RUNNING
Y
ES
V
ERIFY THE VOLTAGES
ON EACH OF THE
CONNECTORS LISTED IN
SECTION
A
RE ANY OF THE
VOLTAGES MISSING
Y
ES
V
ERIFY THAT THE
SUPPLY IS NOT BEING
LOADED DOWN BY ONE
OF THE BOARDS
I
S IT BEING
LOADED DOWN
Y
ES
R
EPLACE THE
ASSEMBLY LOADING
DOWN THE SUPPLY
VOLTAGE
R
EPLACE THE POWER
SUPPLY
6-50 Maintenance
Note: The power supply will not power up if the +2.5V, +5VA and
-5VDIG are not loaded by the Acquisition Board.
N
O
?
4.6.4.
P S
OWER UPPLY IS NOT
SUSPECTED
N
O
THAT VIDEO IS WORKING
PROPERLY
.
R
EPLACE THE POWER
N
O
SUPPLY
M
OMENTARILY SHORT
4 & 5
PINS
FRONT PANEL SWITCH
BOARD USING A PAIR OF
TWEEZERS
D
ID
THE UNIT TURN
?
ON
Y
ES
R
EPLACE POWER
,
CHECK
SWITCH
R PFC A
EPLACE
OF THE
V
ERIFY POWER SWITCH
N
CABLE IS PLUGGED INTO
O
CPU
BOARD
S P
HORT IN
14 P
OF THE ROCESSOR
BOARD POWER
CONNECTOR TOEGTHER
USING A PAIR OF
TWEEZERS
D
ID
THE UNIT TURN
?
ON
Y
ES
R
EPLACE PROCESSOR
BOARD
M
EASURE VOLTAGE
BETWEEN WHITE AND
BLACK WIRES AT
OF MAIN POWER SUPPLY
I ~160VDC?
N
SSY S IT
O
Y
ES
R
EPLACE MAIN POWER
SUPPLY
13
TO PIN
No
5CN2