CMT-DH3, CMT-DH5BT, CMT-DH7BT, HCD-DH3, HCD-DH5BT, HCD-DH7BT - Sony Audio Service Manual (repair manual). Page 3

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3
HCD-DH3/DH5BT/DH7BT
SELF  DIAGNOSIS  FUNCTION
SAFETY  CHECK-OUT
After correcting the original service problem, perform the following
safety check before releasing the set to the customer:
Check the antenna terminals, metal trim, “metallized” knobs, screws,
and all other exposed metal parts for AC leakage.
Check leakage as described below.
LEAKAGE  TEST
The AC leakage from any exposed metal part to earth ground and
from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microamperes.).
Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturers’ instructions to use these
instruments.
2. A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a
VOM or battery-operated AC voltmeter. The “limit” indication
is 0.75 V, so analog meters must have an accurate low-voltage
scale. The Simpson 250 and Sanwa SH-63Trd are examples
of a passive VOM that is suitable. Nearly all battery operated
digital multimeters that have a 2 V AC range are suitable.  (See
Fig. A)
Fig. A.
Using an AC voltmeter to check AC leakage.
1.5 k
0.15 
µ
F
AC
voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Earth Ground
Self-diagnosis Function
(When letters/numbers appear in the display)
When the self-diagnosis function is activated to prevent the system from 
malfunctioning, a 5-character service number (e.g. C 13 50) with a 
combination of a letter and 4 digits appears on the TV screen and the front 
panel display. In this case, check the following table.
First 3 characters of 
the service number
Cause and corrective action
C 13
This disc is dirty.
 Clean the disc with a soft cloth.
C 31
The disc is not inserted correctly.
 Restart the system, then re-insert the disc 
correctly. 
E XX
(XX is a number)
To prevent a malfunction, the system has 
performed the self-diagnosis function.
 Contact your nearest Sony dealer or local 
authorized Sony service facility and give 
the 5-character service number.  
Example: E 61 10
When displaying the version number on the TV screen
When you turn on the system, the version number [VER.X.XX] (X is a 
number) may appear on the TV screen. 
Although this is not a malfunction and for Sony service use only, normal 
system operation will not be possible. Turn off the system, and then turn 
on the system again to operate.
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