Philips V30 manual Warning and Notes, 107T5, Go to cover page, Warnings, Esd

Warning and Notes

107T5 17

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Warnings

1. Safety regulations require that the unit should be returned in its original condition and that components identical to the original components are used. The safety components

are indicated by the symbol .

2. In order to prevent damage to ICs and transistors, all high-voltage flash-overs must be avoided. In order to prevent damage to the picture tube, the method shown in Fig. 1 should be used to discharge the picture tube.

Use a high-voltage probe and a multimeter (position DC-V). Discharge until the meter reading is 0 V (after approximately 30 seconds).

3. ESD

All ICs and many other semiconductors are sensitive to electrostatic discharges (ESD). Careless handling during repair can drastically shorten their life. Make sure that during repair you are connected by a pulse band with resistance to the same potential as the ground of the unit. Keep components and tools also at this same potential.

4. When repairing a unit, always connect it to the AC Power voltage via an isolating transformer.

5. Be careful when taking measurements in the high-voltage section and on the picture tube panel.

6. It is recommended that saferty goggles be worn when replacing the picture tube.

7. When making adjustments,use plastic rather than metal tools. This will prevent any short-circuit or the danger of a

circuit becoming unstable.

8. Never replace modules or other components while the unit is switched on.

9. Together with the defleciton unit, the picture tube is used as an integrated unit. Adjustment of this unit during repair is not recommended.

10.After repair, the wiring should be fastened in place with the cable clamps.

11.All units that are returned for service or repair must pass the original manufactures safety tests.

Notes

1.The direct voltages and waveforms are average voltages. They have been measured using the Service test software and under the following conditions :

-Mode : 640 * 480 (31.5kHz / 60Hz)

-Signal pattern : grey scale

-Adjust brightness and contrast control for the mechanical mid-position (click position)

2.The picture tube panel has printed spark gaps.

Each spark gap is connected between an electrode of the picture tube and the Aquadag coating.

3.The semiconductors indicated in the circuit diagram(s) and in the parts lists are completely interchangeable per position with the semiconductors in the unit, irrespective of the type indication on these semiconductors.

V

Fig.1