Philips CHASSIS 2B free download

File name PHILIPS CHASSIS 2B tips.pdf

Picture Raster is empty, jumps to protective circuit. Fault 1 Electrolytic 2433 (470µF) is s/c. Position: on the CRT board. The picture is white and shows flyback lines. The appliance goes to protective circuit. Fault 1 D6410 on the picture tube board is defective, therefore power supply resistor R3400 (+200V) is defective, and probably also R3639 next to the line transformer. When changing the bands, ie from band 1, 4 or 5 to 3 or interband S1-10 there is sometimes no picture. Fault 1: Remove the tuner from the chassis. Lift off the cover (board side). Attention; Unsolder the soldering tag. Solder +/2cm bare wire to grounding tags (the ends of 2 contact springs). Refit the cover and pull the bare wires through the opening of the springs. Do not forget to resolder the tag. There is no picture or a bad picture with certain programmes. Fault 1 The appliance does not adjust the off-set channels correctly. Check if the serial No. starts with AG01 or AG02. Replace micro processor IC7830 and fit a resistor between P9 and P8 of plug K4 (1K) and diode 1N4148 between P13 and P9 and anode of IC7830 on pin 13. If the serial No.starts with AG 04 then only fit a resistor on plug K4. Interference in the picture.Fault 1 Interference in the picture on one of the VHS channels. Press on the compartment lid to see if the picture improves. Solder the earthing spring on the lid. Fault 2 During high volume the picture changes. Check if +140V remains. Change R3697/56K. The picture is frayed. Fault 1 Check the control TS7618 and R3633. Fault 2 Check capacitor 2496, C2544/ C2545 and R3544 (synchr.module). Fault 3 Check the video signal. If the line pulse is poorly, then change the MF-unit. All stations show a wavy picture. Fault 1 Replace the earthing connection between the plate and the channel selector with wire. Contrast cannot be controlled. Fault 1: 3V at pin 19 of IC7300. Diodes 6486 and 6490 have been measured and seem ok, however they must be replaced. Fault 2: Check if control voltage at pin 12 of IC7300 changes when you move the contrast regulator. If voltage varies replace D6490 (BAV21; part no. 4822 130 34189). When the volume is loud the picture is wavy vertically in rhythm with the sound. Fault 1: Check if the PSU stabilises at 140V (loosen diode 6705 and check resistor 3697). The picture does not stand still, looks as if its laying next to a station. Fault 1 Check the soldering joints on the synchro. board 7550. Picture collapse depending on volume. Fault 1: Check T7225 and C2153 (15µF). Poor picture because the appliance keeps searching for channels. A good synch. pulse is not present on Pin 28 of the tuner. Fault 1: Replace electrolytics of 0.47 MF, 1.5MF and 47MF in MF section of tuner. Picture varies at high volume. Fault 1: Check if the +140V remains stable, replace R3697 (56K-MR25) 4822 116 51264. White stripes in picture for 2-3 minutes. Fault 1: Loss of capacity in C2571 100µF. Dark screen. No sound. EHT present. 140V,13V ok. All voltages ok. Fault