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HARD DISC DRIVE REMOVAL
MBX-44 Board, IFX-124 Board, DDC-3 Board, V/L Rechargeable
Battery removal
CNX-107 BOARD REMOVAL
DISPLAY ASSEMBLY REMOVAL
LCD SECTION
Monday, August 05, 2013
SONY VAIO - PCG-SR33 - PCG-SR33K - PCG-SR27 - PCG-SR27K - PARTS LOCATION & DISASSEMBLE PROCEDURE
HOW TO TROUBLESHOOT - SONY TRINITRON CTV-25 [BA-4 Chassis TVs] - Protection circuits details
A loss of data, vertical drive, flyback generator signal or
+13Vdc power will cause the protection circuit to shut OFF the TV. The 30Vp-p
retrace pulse from IC541/pin 3 is used as an indication of vertical output
operation. This pulse is reduced to 5Vp-p and monitored by Micro IC001/pin 17.
After two seconds of missing pulses, IC001 will turn OFF the TV set and blink
the Timer light four times.
Troubleshooting
When the TV is shutdown and the Timer/Standby light
blinks four times, the problem is in the vertical or horizontal section. Start
the TV by pressing the Power button. You have two seconds to identify the
missing signal with your scope or voltmeter before the TV shuts down again. Here is a general checklist of items that
will cause the TV to shutdown:
Some causes for the Timer/Standby light to blink four times
and repeat
- No Data/Clock input (IC301/pin 34, 35). This causes NO IC301/pins 13-14 drive output.
- Missing positive or negative 13 voltage to power IC541 at pins 2 or 4. This voltage comes from the FBT.
- Loss of either or both vertical drive signals from IC301/pins 13 and/or 14.
- Loss of horizontal drive resulting in no FBT voltages.
- No fbt/boost output from IC541/pin 3
Automatic Brightness Limiting (ABL)
The purpose of this circuit is to prevent sudden bright
scenes from shortening the life of the picture tube. It does this automatically
by monitoring the picture tube’s current and then using this voltage to limit
the brightness of the picture. The
flyback transformer T504 (secondary) supplies the picture tube’s high voltage.
The ground end of the secondary at T504/pin 11 is current limited by a 100k ohm
resistor, R535. As the picture gets brighter, the high voltage current
increases, causing a voltage drop across R535. This ABL voltage decreases with
increasing brightness.
Voltage divider R533, R534 and R532 bias this ABL line with
a positive voltage that is applied to Jungle IC301/pin 3. A lower ABL voltage
decreases the level and gain of the RGB waveform. This is how ABL section uses
the Jungle IC to keep the brightness within a reasonable operating range.
OCP Protection
One part of the protection circuit is shown here in block
form. The over current Protection (OCP) stage shuts OFF the TV during a fault.
Q571 is used to monitor the current flowing through the FBT and horizontal
output transistor. If the current becomes excessive, Q571 conducts, grounding
out the DC voltage from the Jungle IC301/pin 18. This ground causes IC301/pin
34 to send data to Micro IC001/pin 37. The data instructs IC001 to shut OFF the
TV, allowing the horizontal output transistor to cool down.
Vertical Output Failure
Pulses from the vertical output IC are monitored for
activity by IC001. Two signals are
output when the vertical output stage is receiving the drive signal and
amplifying. The main drive signal goes to the vertical deflection yoke. The
other signal is made inside the vertical Output IC541’s flyback generator and
output pin 3. At pin 3 is a 30Vp-p pulse that is reduced by R549 and limited by
zener diode D001 to 5Vp-p. IC001/pin 17 receives and monitors this 5-volt
vertical pulse to prove the Vertical stage is operating.
If IC001 detects a loss of these vertical flyback pulses for
two seconds, IC001 will turn the TV OFF. As part of IC001’s diagnostic program,
after the set is turned OFF (but not unplugged), the Timer/Standby light will blink
four times, pause and repeat. This indicates the problem is a loss of vertical
signal. Unfortunately, +13Vdc that
powers the vertical IC541 comes from the horizontal stage (FBT). Therefore, a
horizontal failure will also cause the light to blink four times, pause and
repeat.
Excessive FBT Voltage
An open safety capacitor C508 or high B+ voltage can cause
the flyback transformer (FBT) to produce an undesirably high secondary voltage. The FBT’s secondary voltage at T504/pin 7 is
monitored for excessive signal level. This
stage consists of T504, D574, IC521, Q300, IC301 and IC001. Flyback pulses are rectified and compared to
a reference voltage to determine if they are excessive. The 120Vp-p T504/pin 7
pluses are rectified by D574 into 109.2Vdc. This voltage is reduced further to 8.76Vdc
by voltage divider resistors R583, R582 and R584 and applied to the + input of
comparator IC521/pin 5. As long as the voltage at pin 5 is no higher than the
9.7Vdc at the negative input pin 6, the output of IC521/pin 7 will remain LOW
(1.34Vdc). The Jungle IC detects the
comparator output. The LOW from comparator IC521/pin 7 is applied to Q300/base,
keeping it OFF as if it were not in the circuit. This allows the horizontal
pulses from Q502/collector and the internal voltage of 3.4Vdc to remain at
Jungle IC301/pin 18 for normal operation.
When the FBT voltage is excessive, the TV is required to
shutdown. An excessive FBT voltage level will cause IC521/pin 7 to output a
HIGH, which will turn ON Q300. When Q300 saturates, the 3.4volts from IC301/pin
18 are grounded. This ground immediately causes shutdown data to output
IC301/pin 35 to the Micro. The Micro receives this command and produces a HIGH
at pin 6 to shut off the TV. After the TV is shut OFF, the Timer/Standby light
blinks two times, pauses and repeats for as long as the set is plugged into
120Vac.
Excessive B+ current Failure
Leakage in the Horizontal output transistor Q502, shorts in
flyback transformer T504 or a short in a secondary winding would draw excessive
current from the B+ line. Excessive current drain will cause the TV to shut
down, allowing itself to cool off. Components
involved in this stage are R571, Q571, Q300, IC301 and IC001. All the current from the B+ source flows through
resistor R571. Transistor Q571’s
emitter-base junction is essentially placed across this resistor. Resistors
R574, R575, R572, and R573 pre-bias Q571. C571 across Q571/b-e prevents rapid
scene changes from turning Q571 ON and triggering the protection circuit. If R571 drops sufficient voltage to turn ON Q571, its
conduction will apply a positive voltage through D581 into the base of Q300,
turning it ON as well. When Q300 turns ON, the 3.4Vdc from IC301/pin 18 is
grounded out. This causes IC301 to send shutdown data from pin 34 to IC001/pin 37.
IC001 responds by shutting OFF the TV set when pin 6 is brought HIGH. After the
TV is shutdown, the Timer/Standby light blinks two times, pauses and repeats
for as long as the set is plugged into 120Vac.
During a failure that causes the TV to shutdown
or go into blanking, the Timer / Standby light D002 blinks, pauses and blinks
again. The number of times it blinks identifies the defective stage:
|
Standby Light Blinks
|
TV Symptom
|
Problem Circuits
|
|
2 times, pauses and repeats
|
Shutdown. TV powers OFF.
|
Excessive B+ current
demand or high FBT pulse amplitudes.
|
|
4 times, pauses and repeats
|
Set Turns OFF
|
Vertical Failure (may also be Horizontal Failure since the
vertical IC is powered by the
FBT.)
|
|
5 times, pauses and repeats.
|
1. Raster, but no video
2. Sound OK
|
White balance failure, weak picture tube or Low G2
voltage.
|
|
Continues to blink once a second
|
No or defective Jungle
IC301 communications.
|
No reply from an IC (data bus is busy -grounded or held
HIGH)
|
|
|
Timer / Standby light – blinks two times
The TV is shutting down because there is an excessive
current drawn by the Horizontal Output Transformer or Transistor. After
checking for shorts in these stages, test the protection trip circuitry.
Testing the Protection Circuitry
- Locate Q300/base. The collector lead of this surface mount transistor is by itself. If the collector is pointed up, the base lead is at the left.
- Monitor the DC voltage with a DVM (peak reading is preferred).
- Turn ON the TV.
- The normal voltage should be less than 0.5Vdc. If it is less than 0.5Vdc before the TV turns OFF again, there is a problem in the protection circuit at Q300 or IC301. Test Q300 for leakage or replace. Move your DVM probe to IC301/pin 18 and turn ON the TV. If this voltage stays below 2Vdc, Q300 is leaky. If above 2Vdc, IC301 may be defective.
- If the voltage at Q300’s base is HIGHER than 0.5Vdc, the problem may be in IC521, Q571, or in the circuitry.
- Place your DVM at IC521/pin 7 and turn ON the TV. The normal voltage should be less than 2Vdc. If it is higher, the problem is around IC521 or there is excessive FBT voltage from an open safety capacitor (C508) or high B+ voltage. Reduce the AC voltage and monitor the voltages at IC521/pins 5 &6. The voltage at IC521/pin 6 is fixed at the D573 zener voltage plus 0.6V (D572). The normal voltage at pin 5 should never exceed 10Vdc. If the voltage at IC521/pin 5 is HIGHER than 10Vdc, the problem is in the circuit’s safety capacitor or high B+ voltage. If the voltage at IC521/pin 5 is Lower than 10Vdc, the problem is about IC521.
- If none of the voltages around IC521 were high, the problem must be around Q571, a defective horizontal output transistor or transformer.
- Place your DVM at Q571/collector. Turn the TV ON. This voltage should not rise above 10Vdc. If this voltage is HIGH, suspect Q571, R571 and other resistors in the area. If these protection parts test OK, there is a heavy current demand on the B+ line. The problem may be a short at the FBT secondary windings.
Timer / Standby light – blinks four times
A vertical deflection failure or horizontal drive failure is
indicated.
Test the horizontal section by using one of these tricks:
* Place your scope probe by the FBT and turn ON the TV. You
will see the horizontal signal if the drive path from the Jungle IC to the FBT
is OK
* Listening to the frying sound at the yoke is another
indicator of horizontal signal arriving at the yoke
- Test the vertical stage by using the scope probe to monitor the vertical drive signal and the DVM to measure the positive and negative supply voltages to the vertical IC541 at turn ON.
- Test the Protection circuitry by placing your scope lead at the Vertical Output IC541/pin 3. You should see a 30Vp-p pulse there. If it is present, this pulse is not getting to IC001/pin 17. Replace zener D001 if shorted.
Timer / Standby light – blinks five times
This failure is caused by a problem in the video output IK
circuit. Turning up the screen control will let you see light on the screen so
you can make an evaluation of the problem.
SONY TRINITRON - CTV-25 [BA-4 Chassis] - SELF DIAGNOSIS - BLINKING CODES & DETAILS
A dormant intermittent problem is difficult to detect. The
BA-4 chassis Control Tuning System IC001 has a program to record the number of times
the TV has failed in the first three categories listed above. This information
can be accessed and displayed on the TV screen as long as the set remains
plugged in.
SELF DIAGNOSTIC ACCESS
With the set OFF, aim the remote at the TV and press the
following remote buttons in this sequence:
1. Display
2. 5
3. Volume Down [ – ]
4. Power On.
The TV will power ON and display the self-diagnostic page.
This self-diagnostic display will overlay the TV or video picture.
At the left of the self-diagnostic TV screen display are the
numbers 2, 4 and 5. These represent the number of times the Timer/Standby light
was blinking. The numbers 3 and 101 are not used (N/A). The column on the right side shows the
number of failures that have occurred since the program was reset. Up to 99
failures can be recorded. Although the
self-diagnostic page will display the number of times a failure has occurred,
it will not be able to tell you exactly where the problem is, only that it
exists.
Self-Diagnostic is new in the series BA-4 TV chassis. It
uses a blinking light or OSD to notify you if there is a failure caused by the
following:
1. Excessive fly-back current or amplitude;
2. No Vertical sweep; or
3. No green automatic white balancing signal.
TIMER/STANDBY LIGHT
The number of times the Timer/Standby light blinks indicates
what failure the Control Tuning System Microprocessor IC001 detects. IC001 will
shut off or blank the TV set to protect itself. The Standby/Timer light will
continue to blink as long as the TV is plugged into AC power.
The number of times the TV has failed is held in memory. As
long as there is failure information present, the standby light will blink when
the set is tuned OFF. Unplugging the TV
set will clear the memory information and stop the blinking.
FAILURE CHECK LIST
Some of the reasons for the failure could be in this
checklist.
When the problem is intermittent, you will have to probe
further by monitoring the horizontal output transistor temperature and the TV’s
current consumption to see if it is high, vibrate and possibly “bake” the set
to force the intermittent failure to reveal itself.
MEMORY CLEAR
Unplugging the TV from AC power resets the stored failure
information and stops the blinking light. The memory is cleared once standby
+5Vdc is removed from the Control Tuning System Microprocessor IC001. It can
also be manually cleared by first pressing 8 and then pressing ENTER while you
are in the self-diagnostic mode.
- Unplug the TV from AC. Ã Removing AC power clears the memory at any time.
- From the remote control. Ã Press buttons: 8,then press ENTER.
Self Diagnostic Exit:
Shutting off power to the set retains the memory information
and allows you to return to the TV picture.
SELF DIAGNOSTIC CIRCUIT
The self-diagnostic program is contained in the Control
Tuning System IC001. The number of problems is detected by the program is
stored in IC001. This number remains in IC001’s resident memory as long as the TV
remains plugged into AC and is not manually cleared.
When the TV set is turned ON, IC001 monitors three TV
conditions using two inputs at pins 37 and 17. These TV conditions are:
1. Vertical Failure - In normal operation, Vertical Output
IC541’s “Ref” pin 3 outputs a 30Vp-p pulse (1msec pulse width). This voltage is
reduced by R549 and clamped to no higher than 5Vp-p by D001. These vertical pulses from IC541/pin 3 are
monitored by Control Tuning System IC001 at pin 17. A vertical drive failure causes no pulses to be generated. If
these vertical pulses are lost for two seconds, IC001 will turn OFF the TV to prevent
the vertical deflection failure from damaging the CRT. However, the front panel
Timer/Standby light continues to blink four times, pauses and repeats, even
though the set is OFF.
2. Excessive Current Demand/Excessive FBT pulse
amplitude – Y/C Jungle IC301 monitors both of these conditions at input pin 18.
Normally there are horizontal pulses applied to IC301/pin 18 when the TV is ON. When there is excessive current being drawn
by the FBT or Horizontal Output Transistor, the horizontal pulses are grounded
out. The Y/C Jungle IC301 detects this loss from pin 18 almost immediately and sends
data from IC301/pin 35 to IC001/pin 37 (even in normal operation, there is
always data on this line). IC001 shuts OFF the TV to protect itself. The Timer/Standby light blinks two times,
pauses and repeats to indicate the failure.
If flyback (FBT) pulses were abnormally high, perhaps as a result of an
open resonate capacitor (C508 in this set), the TV would similarly shut down.
Higher than normal FBT pulses result in a high DC voltage that also grounds the
horizontal pulses at IC301/pin 18. The loss of horizontal pulses is detected
and data is sent from IC301/pin 35 to IC001/pin 37 for the TV to shut OFF. The
Timer/Standby light continues to blink two times, pauses and repeats after the
failure.
3. White Balance Failure – Jungle IC301 initiates CRT drive
and monitors CRT cathode current at pin 21. The amplitude of the three IK pulses
that return to IC301/pin 21 represent the level of red, green and blue CRT
cathode emissions. Their amplitudes are used to white balance the picture while
the TV is ON.
This IK circuit is designed to look for three IK
pulses returned from the picture tube. If IC301 detects a missing IK pulse
within two seconds after the set is turned ON, the video is blanked (muted).
The two seconds allow time for the picture tube to warm up. This blanking state
is relayed as data from IC301/pin 35 to C001/pin 37. IC001 causes the
Timer/Standby light to blink five times, pause and repeat. The set remains ON
during this video failure, so the sound is still present.
When there are multiple failures, the two blinking light
failure has a higher priority over the four blinking light failure. By the same
logic, the four blinking light failure has a greater priority than the five
blinking light failure. For example, if multiple failures caused all of the
two, four and five blinking light failures to be stored in memory, the
Timer/Standby light would blink two times, pause and repeat when the TV shut
down. The number of failures has nothing to do with how many times the light
blinks.
Display
By using the TV’s remote control, you can access this
failure information stored in memory. Once IC001 receives the self-diagnostic
access command at pin 12, IC001 powers ON the TV. The failure information from
IC001 is sent to the Jungle IC301 as On Screen Display (OSD) video levels. A “OSD Blk” signal accompanies the OSD video
levels from IC001 into IC301. This analog input voltage at Jungle IC301/pin 29
is used to darken (blank) the main RGB picture signal at the instant the OSD
character is to appear and enable the OSD. Since IC301/pin 29 is an analog
input, 0Vdc input leaves the main picture at normal brightness. 2Vdc input reduces
the picture to half brightness and 5Vdc blanks or mutes the picture.
While the main picture is at half brightness, the OSD
self-diagnostic page is displayed at normal brightness and appears as an
overlay to the main picture.
Sunday, August 04, 2013
DURABAND - T6605VF – T6705VF – TV/VCR COMBO - VCR MECHANISM SERVCE
Method for Manual Tape Loading/Unloading
To load a cassette tape manually:
- Disconnect the AC plug.
- Remove the Top Case and Front Assembly.
- Insert a cassette tape. Though the tape will not be automatically loaded, make sure that the cassette tape is all the way in at the inlet of the Cassette Holder. To confirm this, lightly push the cassette tape further in and see if the tape comes back out, by a spring motion, just as much as you have pushed in.
- Turn the LDG Belt in the appropriate direction shown in Fig for a minute or two to complete this task.
- Disconnect the AC plug.
- Remove the Top Case and Front Assembly.
- Make sure that the Moving guide preparations are in the Eject Position.
- Turn the LDG Belt in the appropriate direction shown in Fig. until the Moving guide preparations come to the Eject Position. Stop turning when the preparations begin clicking or cannot be moved further. However, the tape will be left wound around the cylinder.
- Turn the LDG Belt in the appropriate direction continuously, and the cassette tape will be ejected. Allow a minute or two to complete this task.
- Disconnect the AC Plug.
- Remove the Top Case and Front Assembly.
- Turn the LDG Belt in the appropriate direction shown in Fig. M1. Release the locking tabs shown in Fig. and continue turning the LDG Belt until the Cassette Holder comes to the tape-loaded position. Allow a minute or two to complete this task.
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DAYTEK - LC1508NT – LC1521NT – LC2018NT - HOW TO ENTER SERVICE MODE [Fcactory Mode] - Universal Remote Control Set-up Codes
- Using the remote control, press Menu button once first.
- Then press PRE.CH (or named RECALL) button five times, and you can see manufacture menu on the LCD panel.
- Press the channel +/- button to selection the sub menu of factory menu (including F, E, UOCIII, RGBTemp, Temp, and press the Vol + to enter the sub menu and setting the value.
- Press the MUTE button again and again or turn off the TV, it can exit the Factory Menu.
UNIVERSAL REMOTE CONTROL SET-UP CODES
HOW TO REMOVE - Ink Supply Tube Assy & Adapter Cover - EPSON L800 & EPSON L801 - COLOR PRINTER
- Place the Ink Supply Tube onto the Tube Guide Sheet with its Tube Porous Pad side down.
- Connect the Ink Supply Tubes (x6) to the Joint.
- Insert the section A of the Tube Guide Sheet Sub from the top into the hole of the Tube Guide Sheet Sub to secure it.
- Attach the Tube Holders (x3) and secure them with the screws in the order shown in the figure.
- Hold the Ink Supply Tube by the Adapter side and flip it over as shown in the figure, then put a marking on the bottom side of the Ink Supply Tube 70 mm from the Tube Clamp nearest to the Adapter.
- Connect the Ink Supply Tube to the Adapter, and install the Adapter to the CR Unit.
- Route the Ink Supply Tubes through the grooves of the CR Unit, and align the markings on the Ink Supply Tubes with the edge of the grooves as shown in the figure.
ADAPTER COVER
- Attach the Tube Guide Sheet to the Adapter Cover.
- Insert the dowels (x2) of the Adapter Cover into the holes (x2) of the CR Unit and engage the hook of the Adapter Cover to the CR Unit.
- Make sure no Ink Supply Tubes are caught, then secure the Adapter Cover with the screw (x1).
- After installing the Adapter Cover to the CR Unit, move the CR Unit from side to side while holding the Timing Belt to make sure that the Ink Supply Tube Assy does not apply extra load of the CR Unit movement.
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Be careful not to damage or peel off the film of the
Adapter.
Use a precision screwdriver when releasing the hooks of the
Adapter.
When connecting the Ink Supply Tubes to the Adapter, make
sure the red lines on the Ink
Supply Tubes are facing upward as shown in the figure above.
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