HITACHI - 42EDT41 CMP420V1 CMP420V2A TROUBLESHOOTING
HITACHI PLASMA 42EDT41 CMP420E1 CMP420V2A - FRONT LED LAMP INDICATIONS
When the indicating lamp lights in orange or the message "No Signal', 'Power Save" or "Invalid Scan Freq" appears on the screen, there is something unusual about the status of reception. See the Signal Check or Power Save mode or symptoms that seemingly appear to be failures in the owners guide.SIGNAL CHECK
When the Mode Display is set to ON, the input signal is
switched or when the Recall button is pressed.
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A guide is displayed for the input terminal and the
horizontal and vertical sync frequency
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When the sync signal is no longer detected.
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When the input signal does not match the monitor
specifications or is in an unstable status.
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A guide displays Invalid Scan Freq.
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Indicating lamp
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Power status
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Operating
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Off
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Off
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When main power switch is set og OFF
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Lights red
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Off [standby]
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When the main poser switch is ON, and the OFF button on
the remote control or the Sub-Power button on the underside of the fronts of
the fame is OFF.
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Lights green
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On
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When the main power switch is On, and the ON button on the
remote control or the Sub-Power button on the underside of the front of the
fame is ON
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Lights orange
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Off [power save]
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When the main power switch is On, and the ON button on the
remote control or sub-power button on the underside of the front of the fame
is ON
However, the state in Power-save mode.
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DVI Doesn't work Clean the DVI input contacts with Isopropyl Alcohol using a stiff thin bursh. Some times contaminants can cause poor connections on the DVI and/or HDMI inputs. LINES OR BARS IN THE PICTURE Vertical thin back line at the right side of the picture
- Addresses open [line off]. Vertical influence from the control, X-Drive Left and Right PWBs and COF. If the line is on the front Right, the X-drive Left PWB would be involved.
The screen can be broken down to 7 vertical columns. Each of the
connectors from the Control, X-Drive Left and Right PWBs controls each
column. Try to determine which area of the screen is effected to
determine the PWB involved. Also, if the COF is defective, the panel is
defective and can't be repaired.
Vertical thin white line at the right side of the picture.
- This defect also should be considered as described above.
HORIZONTAL WHITE LINE AT THE BOTTOM OF THE PICTURE
- SUS short [line on] Horizontal Sustain Influence for Z and Y sustain PWBs, Y Drive Upper and Y Drive lower PWBs.
If the line is on the bottom side the back X-Drive Left PWB would be
involved or the Z-Sustain output from the bottom connector.
The screen can be broken down to 8 horizontal rows. Four from the
Upper Drive PWB and the other four from the Lower Drive. From the Drive
PWBs; 4 from Upper Drive PWB and 4 from the Lower Drive PWB; and two
rows from the Z-Sustain PWB (Top & Bottom). Each of the connectors
from the control, X-Drive Left and Right PWBs controls each column. Try
to determine, which area of the screen is effected to determine the PWB
involved.
HORIZONTAL BLACK LINE AT THE BOTTOM OF THE PICTURE.
- This defect also should be considered as described above.
- When replacing the Z-Sustain PWB, the P3 connector may be moved away from P2 connector as it was on the original PWB.
- The new replacement PWB should come with a new P3 connector cable, but if doesn't, replace the P3 connector with the new one [Part number: 6631Q20003C]
- The P3 connector goes from the Z-Sustain PWB to the X-Drive Right PWB
SYMPTOM: THE UNIT WOULD POWER ON, BUT WITH NO PICTURE
- The unit did have sound.
- The fornt power LED was on.
When power button was pressed, the unit will power ON like normal, however there was no picture produced.
Power the unit up with color bar input, color turned off from the generator.
First check the Vs +180AC +195V on the Y-Sustain PWB. Check on the F2 fuse.
Note: Vs voltage should be same as the voltage label.
On the Y-Sus PWB, check the right hand side of R30 for +105.5V. Left hand side should be ( -17.36V).
If OK, Power Supply PWB is providing VS voltage.
If not, confirm VS from the Power Supply PWB is getting to the Y-Sustain PWB.
On the Y-Sus PWB, check the right hand side of R321 for ( -65.2V). Left hand side should be ( -16.32V).
If OK, Y-Sus PWB is getting Vy. Vy van vary dependent upon the panel label. Check the lable for exact voltage to measure.
If not OK, defective Y-Sus PWB. Vy voltage -70V to -80V generated by Y-Sus PWB DC to DC converter.
HITACHI PLASMA 42EDT41 CMP420V1 CMP420V2A Troubleshooting
SYMPTOM: Unit would power ON but with no picture.
- The unit did have sound.
- The front power LED ON.
Check the test point JP on the Y-Drive PWB Upper and Lower PWB.
- Normal should be [ -16 with color bars with color turned OFF as input signal]. This varies due to picture content.
- This voltage is extremely high ( >85V) and doesn't fluctuate, except a defective Buffer on the underside of the Y-Drive Upper and Lower PWBs of a defective Y-Sustain PWB.
- Check the Outputs of Buffers on the Y-Drive PWB upper and lower PWB.
- Normal should be 50.9V. This voltage will vary due to picture content and flucuate 5V up or down.
- If this voltage is extremely high and not fluctuating, except a defective Buffer on the under side of the Y-Drive Upper and Lower PWBs or
- A defective Y-SUS PWB.
- A defective Buffer will make all output voltages test High and the JP test point High.
- Unplug the connectors one by one from the Y-Drive PWB to the panel. If the voltage returns to normal then the buffer feeding this connector is bad. There are 4 connectors for each Y-Drive PWB. 4 for Upper and 4 for Lower.
- If only have a defective buffer, when the right connector in unplugged, the other voltages will remain to normal [50.9V] and the picture will return , but only on the top of bottom half.
- In case only need to replace the Y-Drive PWB with the defective buffer.
- Y-Drive Upper PWB part number [TS05672]
- Y-Drive Lower PWB part number [TS05673]
SYMPTOM: The unit would power ON but with no picture.
- The unit did have sound.
- The front power LED is ON.
If after all connectors to panel assembly from Y-Drive boards, the voltages still remain incorrect:-
- Remove the Y-Drive PWBs. Look at the buffer underneath. May find small burn marks on the buffer. Any one of them either Upper or Lower Y-Drive PWB. If the voltage check showed defective buffer or any one buffer is found to be burned, replace the following.
- Y-Sustain PWB. Part number [TS05679].
- Y-Drive Upper PWB. Part number [TS05672]
- Y-Drive Lower PWB. Part number [TS05673]