Samsung PN22NSBU, PN22NS Troubleshooting

PN22N* 5-1

5 Troubleshooting

5-1 Parts Level Troubleshooting

Notes: 1. If a picture does not appear, fully rotate the brightness and contrast controls clockwise and reinspect.

2. Check the following circuits.

• No raster appears: Power circuit, Horizontal output circuit, H/V control circuit, and H/V output circuit.

• High voltage develops but no raster appears: Video output circuits.

• High voltage does not develop: Horizontal output circuits.

5-1-1 No Power Supply

Check and replace FH601, D601,

Q601, Q604, and IC611.

Done.

Repeating start?

Done.

No

Yes

IC611 Drain waveform is right?

Check and replace IC611.

Yes

No

Q601 Drain waveform is right?

Check IC601 and D602.

Yes

No

Q604 Drain waveform is right?

Check IC602 and IC603.

Yes

No

WAVEFORMS

5

2

Q601 Drain

CH1 RMS = 226.0V

4

Q604 Drain

CH1 RMS =434.4V

5

IC611 Drain

CH1 RMS = 333.2V

2

4

5 Troubleshooting

5-2 PN22N*

5-1-2 DPMS Failure

Check signal source

H/V sync video level.

Make No H/V sync (power off mode)

LED toggle green color, blinks?

Check IC201 Pin 30 and 31.

Yes

No

IC201 Pin9 High?

Check IC201 Pin 9.

Yes

No

Heater voltage is off?

Check IC201 Pin 10.

Yes

No

Done

5 Troubleshooting

PN22N* 5-3

5-1-3 H_Deflection Failure

Q403 Drain waveform is right?

Check R403, D416 and +210 V line.

Yes

No

Q404 Gate

waveforms are right?

Check Q404 and R415.

Check +80 V line.

Yes

No

Q405 collector

waveforms are right?

Check and replace D410 and Q405.

Check DY connector connection.

Yes

No

Check some parts around

QS202 and QS203.

ICS202 Pin 26

waveform is right?

Check some parts around ICS202.

Yes

No

WAVEFORMS

20

21

23

14

14

ICS 202 #26

CH1 RMS = 8.88 V

21

Q404 Gate

CH1 RMS = 7.67 V

23

Q405 Collector

CH1 RMS =353.2 V

20

Q403 Drain

CH1 RMS = 188.4 V

5 Troubleshooting

5-4 PN22N*

5-1-4 S_Correction Failure

S1~S6 signals are right at each

frequency block?

Check S1 ~ S6 signal.

Check and replace C451~ C457,

Q451~Q455, and Q456~Q460 .

Yes

5-1-5 H_Lin. Failure

ICS201 Pin 22 voltage varies with

different H_Lin. DAC values?

IC403 Pin 7 and 8 voltage varies

with different H_Lin. DAC values?

Check +12 V line.

Check some parts around IC403.

Check L403.

Yes

Yes

No

Check and replace ICS201.

No

Replace ICS201.

No

5-1-6 Invariable H_Size

ICS201 Pin 20 voltage varies with

different H_Size DAC values?

Check and replace ICS201.

No

5 Troubleshooting

PN22N* 5-5

5-1-7 Abnormal H_Size

T402 Pin 10 waveform is right?

Check and replace T402.

Check some parts

around ICS201 Pin 20

Yes

No

5-1-8 Side Pin or Trap Failure

ICS202 Pin 24 output exists?

Check and replace ICS202.

5-1-9 Para. or Pin Balance Failure

ICS202 Pin 24 output varies with

different DAC values?

No

Replace ICS202.

No

WAVEFORMS

19

19

T402 #10

CH1 RMS = 11.52 V

5 Troubleshooting

5-6 PN22N*

5-1-10 Tilt Failure

IC201 Pin 21 output duty varies

with different DAC values?

IC801 Pin 7 and 9 output varies

with different DAC values?

Check and replace IC801.

Check and replace Tilt coil.

Yes

Yes

No

Check and replace IC201.

No

Check tilt connector connection

5-1-11 V Deflection Failure

±13 V line is on?

ICS202 Pin 23 output exists?

Check and replace ICS202.

Yes

Yes

No

Check and replace D616 and D618.

No

IC301 Pin 1 input exists?

Check R300 and R304.

Yes

No

IC301 Pin 6 output exists?

Check and replace some parts

around IC301.

Yes

No

Check V DY connector connection.

16

25

16

ICS202 #23

CH1 RMS =3.668 V

25

IC301 #6

CH1 RMS = 8.72 V