Read Sharp 66GS-62 (serv.man20) Technical Bulletin online
CTV 2004 03 08
Month of Issue: 22
nd
July 2004
Classification:
White
TELEVISION TECHNICAL BULLETIN
Page 2 of 3
Sharp Electronics (UK) Limited
Reference AvW 10 03 2004 - 8
Revision 3
White – Carry out as required
Yellow – Carry out as required and whenever the unit comes in for service
Red – Carry out on all units
Change of Q602
The inner pincushion correction transistor, Q610 was up rated from a SMD device to a wire ended type. The new
transistor is now mounted on the component side of the PWB. If a set comes into the workshop, and this resistor has
not been changed, it is advisable to do so, using the part number for Q610 given below:
Original Q610 Transistor
New Q610 Transistor
Change of Q602 and Heatsink
A larger heatsink was used for Q601 and Q602 to help reduce the operating temperature of these devices. The original
heatsink is 65mm in height; the new one is 110mm in height. If the heatsink has already been changed for the larger
type, it is not necessary to change it again. See the picture relating to the new Q602 for new heatsink.
Q601 Problems
Intermittent line drive, no line drive, varying line width and poor reliability of Q601 can all be traced to the incorrect type
of device fitted to position Q601. We have had several reports of this problem from Service companies who have
purchased the above Transistor from various independent (non-Sharp) Spares suppliers.
Power Factor Circuit Correction
There is a misprint on the schematic diagram. Between the supply line and the emitter of Q704, a 2.2k
Ω SMD resistor
is fitted. Zener diode D714 is connected to the emitter of Q704.
Heater Supply Circuit Changes
On the circuit diagram, the heater supply circuit shows D627 in series with L610, although the diode symbol is not
actually shown. Most chassis have D627 fitted (cathode to L610), but some earlier versions have a 1
Ω resistor in D627
position.
If a fault is experienced with the earlier type of heater supply circuit, it is recommended that the resistor is replaced with
the diode and L610 is changed for the one listed in the service manual. These part numbers are reproduced in the list
below.
Click on the first or last page to see other 66GS-62 (serv.man20) service manuals if exist.