Table of Contents
Advertisement
CHAPTER 2.
21HF2-SS
IMPORTANT SERVICE NOTES
[1] IMPORTANT SERVICE NOTES
Maintenance and repair of this receiver should be done by qualified service personnel only.
1. SERVICE OF HIGH VOLTAGE SYSTEM AND PICTURE TUBE
When servicing the high voltage system, remove static charge from it by Connecting a 10K ohm Resistor in series with an insulated wire(such as a
test probe) between picture tube dag and 2nd anode lead. (AC line cord should be disconnected from AC outlet.)
1. Picture tube in this receiver employs integral implosion protection.
2. Replace with tube of the same type number for continued safety.
3. Do not lift picture tube by the neck.
4. Handle the picture tube only when wearing shatterproof goggles and after discharging the high voltage completely.
2. X-RAY
This receiver is designed so that any X-Ray radiation is kept to an absolute Minimum. Since certain malfunctions or servicing may produce potentially
hazardous radiation with prolonged exposure at close range, the following precautions should be observed:.
1. When repairing the circuit, be sure not to increase the high voltage to more than 30.0kV (at beam 0 μA) for the set.
2. To keep the set in a normal operation , be sure to make it function on 27.0kV ± 1.0kV (at beam 1,000 μA) in the case of the set. The set has been
factory - Adjusted to the above-mentioned high voltage.
*If there is a possibility that the high voltage fluctuates as a result of the repairs, never forget to check for such high voltage after the work.
3. Do not substitute a picture tube with unauthorized types and/or brands which may cause excess X-ray radiation.
3. BEFORE RETURNING THE RECEIVER
Before returning the receiver to the user, perform the following safety Checks..
1. Inspect all lead dress to make certain that leads are not pinched or that hardware is not lodged between the chassis and other metal parts in the
receiver.
2. Inspect all protective devices such as non-metallic control knobs, insulating fishpapers, cabinet backs, adjustment and compartment covers or
shields, isolation resistor- capacity networks, mechanical insulators etc.
Service Manual
2 – 1
21HF2-SS
Advertisement
Table of Contents
