3
PRO-720HD, PRO-620HD, PRO-520HD
Leakage Current Hot Check
Plug the AC line cord directly into a 120V AC 60Hz outlet (do not
use an isolation transformer for this check). Turn the AC power
switch on.
Using a "Leakage Current Tester (Simpson Model 229 equivalent)",
measure for current from all exposed metal parts of the cabinet (input/
output terminals, screwheads, metal overlays, control shaft, etc.),
particularly any exposed metal part having a return path to the
chassis, to a known earth ground (water pipe, conduit, etc.). Any
current measured must not exceed 0.5mA.
ANY MEASUREMENTS NOT WITHIN THE LIMITS
OUTLINED ABOVE ARE INDICATIVE OF A POTENTIAL
SHOCK HAZARD AND MUST BE CORRECTED BEFORE
RETURNING THE SET TO THE CUSTOMER.
High Voltage
This set is provided with a X-ray protection for clearly indicating
that voltage has increased in excess of a predetermined value.
Comply with all notes described in this Service Manual regarding
this hold down circuit when servicing, so that this X-ray protection
may correctly be operated.
Serviceman Warning
In the status of the black picture (video muting is being applied)
when no signal is input, high voltage of this set during operation is
less than 30.5kV. In case any component having some relation to
the high voltage is replaced, confirm that the high voltage is lower
than 30.5kV in the status of the black picture when no signal is
input.
To measure H. V. use a high impedance H. V. meter.
Connect () to earth and (+) to the FBT anode cable connector. (Refer
to section "7.1.2 DISASSEMBLY".)
X-radiation
TUBE : The primary source of X-radiation in this set is the picture
tube.
For continued X-radiation protection, the replacement tube must be
the same type as the original, PIONEER approved type.
The picture tube (CRT Service Assy R, G, B) used in this set holds
complete guarantee against X-ray radiation when the X-ray is sealed
(See page 4). Accordingly, when the current in flowing to the picture
tube (CRT Service Assy R, G, B), be sure to perform it by putting
the tube into X-ray sealed applied state. Avoid absolutely to flow
the current to the picture tube (CRT Service Assy R, G, B) itself.
Moreover, when the voltage of the high voltage circuit becomes
abnormally a little higher, the picture tube radiates X-rays.
Accordingly, when servicing the high voltage circuit be sure to
replace as an assy with the POWER SUPPLY Assy in the manner
in which has been adjusted to perform normal operation.
1.2 PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in PIONEER set have special
safety related characteristics. These are often not evident from visual
inspection nor the protection afforded by them necessarily can be
obtained by using replacement components rated for higher voltage,
wattage, etc. Replacement parts which have these special safety
characteristics are identified in this Service Manual.
Electrical components having such features are identified by marking
with a
on the schematics and on the parts list in this Service
Manual.
The use of a substitute replacement component which dose not have
the same safety characteristics as the PIONEER recommended
replacement one, shown in the parts list in this Service Manual,
may create shock, fire, X-radiation, or other hazards.
Product Safety is continuously under review and new instructions
are issued from time to time. For the latest information, always
consult the current PIONEER Service Manual. A subscription to,
or additional copies of, PIONEER Service Manual may be obtained
at a nominal charge from PIONEER.
Leakage
current
tester
Reading should
not be above
0.5mA
Device
under
test
Test all
exposed metal
surfaces
Also test with
plug reversed
(Using AC adapter
plug as required)
Earth
ground
AC Leakage Test
