Toshiba 26AV52R Service manual

©2009 Toshiba America Consumer Products, LLC.
S.M.A.R.T.
Service Material and Reference Tips
Product: LCD Date: 7/01/2009
Models: 26AV52R, 26AV502R, 32AV52R, 32AV502R, 37AV52R, 37AV502R
Doc Ref/File: SMART2009-LCD509-V4
Purpose: The purpose of this document is to give the service provider
troubleshooting information designed to expedite the diagnosis and service
process to modular/sectional level for Toshiba products.
[The information contained within the document will evolve over time so a version number has
been indicated in the document name. The servicer should always use the latest version
available.]
Table of Contents
Section l Chassis Layout and Plug location
Chassis and Plug Layout…....…………....…..….2
Interconnect………………….………...................3
Section ll Modular Troubleshooting Flowcharts
Dead Set …………………………………………...4
Video Problems …………………....……….......5,6
Audio Problems …………………...………………7
Section lll Technical Aids
Firmware Updates…………………………….…8,9
Factory Mode……………………………………..10
Parts List…………………………….………...…..11
Feedback: Please provide any comments or suggestions about this document
to [email protected] When commenting, please provide
the document and version number on all correspondence.
SMART2009-LCD509-V4 Page 1 of 11

DISPLAY T-CON CN3 LVDS
CN11 ALT
LVDS (26 in)
CN5
IR-REC/LED
CN2
SPKR
MAIN PCB
POWER PCB
P802 PWR
P803 INV
P801 AC
CN8 PWR
CN101
INVERTER
MANUAL
KEYS AND
FRONT
JACKS
SMART2009-LCD509-V4 Page 2 of 11

Inverter
1. 24V<
2. 24V<
3. 24V<
4. 24V<
5. 24V<
6. Gnd
7. Gnd
8. Gnd
9. Gnd
10. Gnd
11. NC
12. BL On 5V<
13. Dim .1 to 3V<
14. NC
Power Supply In/Out
1. Gnd
2. Gnd
3. 24V Aud>
4. 24V Aud>
5. Gnd
6. Gnd
7. Gnd
8. 12V>
9. 12V(Panel Pwr.)>
10. 5V>**
11. 5V>**
12. 5V>**
13. Pwr. On (Enable) 2.4V<
14. AC Det.(PWR Good) .07V>
15. Dim .1 to 3V<
16. BL On 5V<
P
8
0
3
Wiring Interconnect
26/32/37AV52R
26/32/37AV502R
P
8
0
1
A
C
C
N
8
CN1
CN3 LVDS
ALT LVDS (26 in)
Pins 2, 4, 6, 8 –
12V Panel Power M
A
N
U
A
L
K
E
Y
S
A
N
D
F
R
O
N
T
J
A
C
K
S
CN2
SPEAKERS
CN5
CN10
BLANK
IR REC/LED
LED/IR
1. 5V<**
2. IR>
3. GND
4. LED Logo
5. LED Green (Power)
P802
Power PCB
Main PCB
Key
Standby**
Pin 1
Flow <-out >-in
SMART2009-LCD509-V4 Page 3 of 11

Is
5 VDC present
at pins 10, 11, and 12 of
CN8 on the main module
when AC is
applied?
Does
a 2.4 volt on off
signal appear at pin
13 of CN8 when the
on/off button is
pressed?
Yes
Suspect a problem with
the standby 5 volt supply
on the power supply
module.
No
Is the
Power Good
(AC Detect) level
less than .07V at pin
14 of CN8
when AC is
applied?
Yes No
Suspect a problem with
the power supply module.
Does
the secondary
12 volt source appear
at pin 8 of CN8 when
the on/off button is
pressed?
No
No Suspect a problem
with the SYSCON
circuit located on the
Main module.
Yes
Yes
Suspect a
problem with the
Main module.
Dead Set
(No Sound and
No Picture or No LED)
SMART2009-LCD509-V4 Page 4 of 11

When
the input button
is pressed on the
receiver or remote, is
the on screen
display clear and
normal?
NOYES
Using the
power distribution
diagram, are the
voltages normal at CN8
of the power supply
module?
NO
Suspect the
power supply
module.
YES
Replace
the Main
Module.
No or distorted
video
Does
the back light function
normally when the unit
is turned on?
YES
NO
Troubleshoot for
backlight problelms.
Is
the screen
discolored or does it
have streaks and dark
areas on the
screen?
NO
If the LCD Control
Board (T-con) is
available, try it. If this
does not help, replace
the LCD display panel.
***
YES
Examples
*** Warranty Authorization required if
display is replaced in warranty – Go
to www7.toshiba.com for instructions.
Check for LVDS activity at
CN3. If it is present suspect a
problem with the display control
board (Tcon). If it is not present
replace the main PCB.
This signal viewed from
LVDS connector
referencing cold ground.
SMART2009-LCD509-V4 Page 5 of 11

Does
the back light
function and then
turn off or is there a
dark horizontal area
on the
screen?
YESNO
Is
24 VDC present
at pins 1 through 5 of
P803 on the power PCB
when the unit is
turned
on?
YES
NO
Replace the
Power supply
module.
YES
NO
If it is
available , try one or both
inverters. If this does not
help, replace the LCD
display. ***
*** Warranty Authorization
required if display is
replaced in warranty – Go
to www7.toshiba.com for
instructions.
Backlight
Troubleshooting
Replace the
Main module.
Is 4.5VDC
present at pin 16
of P802 shortly (.5 sec)
after the unit is
turned on?
Replace the
display. ***
Remove
AC, then unplug the
LVDS cable(s). Does 24 volts
return when AC is reapplied
and the unit
is turned on?
YES
NO
SMART2009-LCD509-V4 Page 6 of 11

Using
the remote or
the manual keyboard,
access the audio menu to
assure the speakers are on
and the input selection is a
known good source.
Will this restore
audio?
Does the
power supply
generate the audio
supply voltages (24 VDC
at pins 3 and 4 of CN8)
when the unit is
turned
on?
YES
NO
Replace the
power supply
module.
YES
NO
Replace the
Main module
Problem
solved.
No Audio
SMART2009-LCD509-V4 Page 7 of 11

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SMART2009-LCD509-V4 Page 8 of 11

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SMART2009-LCD509-V4 Page 9 of 11

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Factory Mode
The factory mode, necessary adjustments, and update procedures shown below can be
accessed in this unit using the supplied remote control transmitter.


To enter the factory mode, you must press “Left Arrow (<), then Exit, then Enter” within
approximately two seconds. To end this function, press exit or simply turn the television
off.
SMART2009-LCD509-V4 Page 10 of 11