Details Of Display/Detection And Applications; Occasional Defect Self-Diagnostic Function (Mode A); Mechanical Block Self-Diagnostic - Hitachi VM-H675LA Service Manual

1.2 Details of Display/Detection and Applications

Table 1-1 summarizes the details of display/detection of
the self-diagnostic functions and their applications.
Table 1-1 Details of Display/Detection of Self-Diagnostic Functions and their Applications
Details of display/
detection
Application
Detected parts
Cautions
[A Mode]
Parts to be tested
Trouble sensors
Cylinder
Capstan motor
[B Mode]
Set to the
B mode
7 - 2
Occasional defect self-diagnostic
function (A mode)
The system control µP memorizes and
displays the defect data.
(If several defects have occurred,
only the last defect detected is memorized.)
Used when the defective symptom is not
reproduced during servicing.
Trouble sensors
Take-up end sensor (EST)
Supply end sensor (ESS)
Take-up reel sensor (RST)
Supply reel sensor (RSS)
Cylinder (S30)
Capstan motor (CFG)
When the rewind mode is entered, the defect
data is erased.
<Detection/Storage>
System control µP
Defect data (Data of last defect
detected)
Parts to be tested
Trouble sensors
Cylinder
Capstan motor
Loading motor
Mechanism mode switch
Tape detection switches, etc.
Fig. 1-2 Oeration Processes of Self-Diagnostic Functions
Fig. 1-2 shows the operational processes of the self-
diagnostic functions.

Mechanical block self-diagnostic

function (B mode)
Displays the data for the defect that has
occurred when the B mode is set.
Used to detect the cause of the defect (in the
mechanical block or electrical circuits) and to
determine the defective position of the
mechanical block.
Trouble sensors
Take-up end sensor (EST)
Supply end sensor (ESS)
Take-up reel sensor (RST)
Supply reel sensor (RSS)
Cylinder (S30)
Capstan motor (CFG)
Loading motor (LOD, UNL)
Mechanism mode switch
(EJT, UST, REW, LST, FWD, HEC)
Tape detection switches, etc.
Erase prevention tab
detection switch (TAB)
ME/MP detection switch (ME)
Hi-8 MP detection switch (MP)
Cassette holder switch (STG)
Engage the B mode after completing the A
mode.
If the B mode is engaged first, the defect data
may be erased.
Set to the A mode
<Detection>
System
control
Defect
µP
data
<Display>
EVF (LCD)/ Display
(Defective parts
flash)
<Display>
EVF(LCD)/display
(defective parts
flash)