Read Sony HMD-A440 Service Manual online
HMD-A440(E)
2-1
Part Replaced (
[)
RV501
SECTION 2
SAFETY RELATED ADJUSTMENT
When replacing or repairing the shown below table, the following operational
checks must be performed as a safety precaution against X-rays emissions
from the unit.
* Confirm one minute after turning on the power.
• HV Protector Circuit Check
Using an external DC Power Supply, apply the voltage shown below
between cathode of D517 on D board and GND, and confirm that the
HV HOLD DOWN circuite works. (TV Raster disappears)
Standard voltage : 35.70
V DC
Check Condition
•
Input voltage
: 120 ± 2 V AC
•
Input signal
: Cross hatch (white lines on black) at
69kHz (Primary Mode)
•
Beam control
: CONT, BRT ; minimum "0 "
• Beam Current Protector Check
An ammeter in series between FBT 11 pin on D board and GND, then,
decrease gradually the resistance of the variable resistor from
maximum to minimum, and confirm that the Beam Current
Protector Circuite works (TV Raster disappears). The current must
be within the range shown below.
•
Standard current : 1.70
mA
Check Condition
•
Input voltage
: 120 ± 2 V AC
•
Input signal
: Cross hatch (white lines on black) at 69kHz
•
Beam control
: CONT, BRT ; minimum "0"
+0.00
- 0.02
- 0.02
+0.00
- 0.10
- 0.10
HV ADJ
HV Regulator
Circuit Check
HV Protector
Circuit Check
Beam Current
Protector Circuit
Protector Circuit
Check
Part Replaced (
])
D board IC501, C532, C534,
C539, C553, C554,
C555, C556, C558,
C561, R540, R541,
R542, R544, R564,
R567, R568, RV501,
T501 (FBT)
D board IC607, IC901, D515,
D517, C540, C542,
C544, C951, R510,
R543, R547, R549,
R552, R595,
T501 (FBT)
D board IC605,IC607,IC901,
C535, C541,R545,
R546, R548,R550,
R596, R934,
T501 (FBT)
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