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MODEL: Most Samsung plasmas
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ISSUE: Cannot identify whether failure exists in main board, control board,
sustains or PSU.
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DIAGNOSIS: Locate test header on control - should be 4x2 or 6x2.
Jumper appropriate pins (refer to service manual or PCB)

If you get test patterns:
- sustains, PSU, control okay
- main bad (control POSSIBLY bad - if input receiver bad)

If not:
- sustains, PSU, control or main are bad

Then identify failure in PSU - test output voltages
- if bad, fault lies in PSU, shorted sustain or main not turning
the PSU on

Then identify sustain board failures:
- unplug X-main, check if powers up and Y-main functions
(dim picture)
- unplug Y-main, check if powers up
(no picture)

Then identify control board failures:
- test SMD fuses
- scope LVDS waveforms going to control (if possible)

Might be main board failure. To confirm, test main board:
- blindly select audio source using INPUT button
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MODEL: PS42C7HD
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FAULT: Clicking relay, no picture or sound
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DIAGNOSIS: Identify shorted sustain board (X-main or Y-main)
Unplug either board in succession and see if set stops clicking
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FIX: Repair or replace the X or Y-main board
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MODEL: PS42C7HD
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FAULT: No picture or picture with significant maldischarge
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DIAGNOSIS: Requires oscilloscope
Check Y-main waveform (was only about 20Vp-p, should be >400Vp-p)
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FIX: Replace 100uF 50V cap near yellow trafo on Y-main board
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MODEL: LE40A656
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FAULT: Takes 10+ minutes to start up
Does not power up at all (standby LED blinks)
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DIAGNOSIS: Identify bulging caps (high ESR etc.)
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FIX: Replace all secondary side caps
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MODEL: LE40R87BD
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FAULT: Takes 10 minutes to start up
Does not power up at all (standby LED fine)
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DIAGNOSIS: None
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FIX: Replace 2200uF 10V or 1000uF 10V Samwha XC caps
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MODEL: LE40R76BD
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FAULT: Powers up fine with good sound, but only a few random lines on LCD
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DIAGNOSIS: Check 2.5V LDO on T-con board
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FIX: Replace 2.5V LDO on T-con board
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MODEL: LE40A656
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FAULT: Working picture, but random green/magneta noise in fixed bars
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DIAGNOSIS: None
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FIX: Replace T-con board
The 46" (LE46A656) T-con will fit the 40" model w/o issue
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MODEL: LE40A656
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FAULT: Loud grinding sound from rear of set
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DIAGNOSIS: None
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FIX: Clean the T-con fan for the 100 Hz motion interpolator
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MODEL: LE40A656
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FAULT: No side button functionality or power indicator; remote control fine
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DIAGNOSIS: None
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FIX: Reseat the connector for the side buttons & LED on both sides
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MODEL: PSxxC450 series (Plasma)
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FAULT: Powers up with Samsung chime
Very dim picture, corrupted/half missing
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DIAGNOSIS: None
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FIX: Replace X-main board
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MODEL: LW26A33WX
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FAULT: No backlight
Sound is good
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DIAGNOSIS: Test resistance of secondary of all inverter transformers
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FIX: Replace any transformers (usually just one) which measure greater
than 3% out from the majority
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MODEL: LEyyAxxx/LNyyAxxx (yy = screen size, xxx = model code)
Confirmed on LE32A457 and LE40A656
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FAULT: Picture is viewable, but colours are incorrect (pinks/green on dark
sections of image etc.)

Sometimes occurs after changing T-con board
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DIAGNOSIS: None
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FIX: Connect test video feed (which exhibits the problem) to TV and
select the right input.

Enter service mode by placing TV in standby then:
US models: Mute - 1 - 8 - 2 - Power on remote
EU models: Info - Menu - Mute - Power on remote

Service mode should appear over visible video feed.

Access OPTION menu.

Access CONTROL menu.

Change LVDS setting until picture goes back to normal. Users report
that JEIDA works.
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