Saturday, January 28, 2012

FAULT FINDING OF SAMSUNG LA26 R71 [ 26” LCD TV ]

Fault Finding of SMPS [Main Power Regulator Board]

Part –2


NO OUTPUT FROM S.B SUPPLY


Check 300V across CP803 [150MFD/450V], FS 803 (2A), IC 801X (VIPER 22A), BZS 803 (MD1), CS 802 (22MFD/50V), DS 802 (UF4007S). DS 803 (UF 4007S), CS 806 (68MFD/63V) PS 804S(WK707), TS 801S, DS 851 (SB500), CS 852 (470MFD/10V), D853 (6V2 – ZENER DIODE).   Check all these components before switch On the set.  Make sure that all are good,  If there is any component stated above suspected, replace them.

S.B SUPPLY VOLTAGE LESS.

ZDTS 851 (KIA431A), PS804S (WK707), RS 866 (6K8), RS 861 (5K6), RS 862 (33K), ICS801X (VIPER22A).

S.B SUPPLY MORE THAN NORMAL.

PS 804S(WK707), ZDTS 851 (KIA431A), RS 860 (6K8), RS 813 (4.7 OHMS), ICS 801X (VIPER22A).

S.B SUPPLY IS OK, BUT OTHER SUPPLIES ARE LOW OR MISSING.

You have to check well all the below stated components on the power board.  If can, Isolate it from the power board, and check it individually, because, on-board check with multimeter won’t get perfect results.

R 852 (3K3), RS 851 (IK), QS 851 (ZG), RS 803 ( I OHM), DS 803 (RF4007), CS 806 (68MFD/63V), PS 801S (WK707), QS801 (C1008), RS 805 (150 OHMS/2W), QS803 (C1008), RS 908 (2.2 K.OHMS), CS 808 (47MFD/50V), ZDS 806 (WP), CM 810 (47MFD/50V), DM 805 (5K.OHMS), CM 813 (10MFD/50V), ICM801S (F9222L), RM 801 (0.22 OHM), PS 803S (WK707), ZDTM851 (KIA431A).
Continued on part-3


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Friday, January 27, 2012

FAULT FINDING OF SAMSUNG LA26 R71 [ 26” LCD TV ]

Fuse FS801S (6.3A0 blows off frequently
VX801X [INR10D-751], BD 801 [RS605M], DP 801 [UF540], QP801 [FCPH20L60], CP 803 [150MFD-450V], CP 801 [1MFD-630V]
Check these components for short circuit.
FUSE FS803 BLOWS OFF FREQUENTLY
IC 801X [VIPER22A], DS851 [SB 5100], CS 852 [470MFD-10V], ZENER DIODE ZD 853 [6V2-Z].
Check the Zener diode ZD 852 for short.  A common fault.
RM 801 (OE 22), OVERHEATS AND BURNS.
CM 801 [100KPF-630V ], ICM 801 [F9222L]
Short of F9222l short is a common fault.
300VDC ACROSS CP 803 IS MISSING OR LOWER THAN NORMAL
FS801[6.3A], VX801X [INR10D-751], NT 811S [NTC5D-15], BD 801S [RS 605M].  check all these components out from the circuit board.
PICTURE OR RASTER SHAKING HORIZONTALLY [ This is a common fault to most of the LCD TVs]
CP803 [150MFD-400V]  Replace this capacitor.  This is the main smoothing capacitor to rectified main DC voltage.

 Contd.. on part-2

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Thursday, January 26, 2012

TERUMO INFUSION PUMP MODEL STC-508 [MEDICAL ELECTRONICS]

Self checking functions and error displays



[A] When the unit is turned On, all the LCD, LED and backlight repeat On and OFF three times.  Thereafter, buzzer sounds for 250msec.

[B]     Rom Check

When the unit power is ON sub CPU makes a specified summation check.  When there found an error, [Err 1] indication flickers.  When the unit power is turned ON, main CPU makes a specified summation check.  When there is found an error, [Err 2] indication flickers.

[C]    RAM check.

When the unit power is turned On, the SUB CPU checks read/write performance of RAM in use. If there found an error, [Err 1] indication flickers.  When the unit is turned ON, the main CPU checks the read/write performance of  RAM in use.  If there found an error [Err 2] indication flickers.

[D] Motor Rotation Check.

When the unit is powered ON, with door opened, indication comes on.  The motor is rotated simultaneously with buzzer check.  This confirms the input of motor pulse rotation.
Motor rotation check is also made while starting or during purge.  It counts the motor rotation detection pulse, and makes surveillance whether the speed is maintained within about +/--20% the controlled speed.  If it goes out of this range, error judgment is made.  On error judgment, [Err 3] indication flickers.

[E] Check on circuits of air-in-line detecting part and occlusion part.

When the unit is powered ON, without setting a tube (occlusion situation), when bubble is not detected, error judgment is made).  [Err 4 indication flickers.

[F]     E2-ROM check.

When failed to rite in data to E2-ROM correctly [Err 5] indication flickers.

[G] Out of Control Check.

When the communication is interrupted CPU is judged as having out of control.  When the main CPU detects communication errors (time-out-error) the motor indication flickers.  When the sub CPU detects communication errors (re-try over), the sub CPU outputs out of control detection signal [Err 7] indication flickers.

[H] Key Scanning Check.

When the unit power is turned ON, when some SW key other than the unit power key is pressed simultaneously with the unit power key [Err 8] indication flickers.
[I] Unit SW disconnection detection output.
After 5 seconds of switching On the unit by the sub CPU, surveillance on the unit SW disconnection detection starts.   Signal Input detecting unit SW disconnection is read with 1-minute intervals.  When the unit SW disconnection is detected, [Err 9] indication flickers.

[J] Source power shut down check.


When the unit is turned ON, after confirming the hystresis of shutdown written in E2ROM, when using battery power and battery voltage is low, [batter] indication flickers.  Thereafter, source power goes OFF.

[K] Restoration from [battery Err]

To restore, make connection with AC unit power, or switch On unit power again after recharging the battery to voltage exceeding 9,9VDC.

HOW TO HANDLE THE CASSES OF [ERR]-DROP ERR]


Motor comes to a stop.  Buzzer continues to sound.  Also, external alarm relay gives continuous output.
All the LED display goes OFF, except error indication. (when sub CPU goes out of control, display becomes indefinite)
Each LED for air-in-line occlusion and door open ON.  Each LED for battery/regulator unit power .ow battery, stop, and start and purge goes OFF.  (When sub CPU goes out of control, display becomes indefinite.)
Function of all the operating keys, except unit SW, becomes invalid.  To restore, once switch OFF, then switch On again.

This unit runs on 110/115/120/200/220/230/240VAC, 50Hz line current or on 12Volt DC current.  The unit switches automatically to the internal battery for backup power when line current is not supplied because the power cord has been unplugged, a power failure has occurred, or some other reason.  The battery charges whenever the unit is connected to power source, regardless of whether the power is ON or OFF.

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TERUMO INFUSION PUMP MODEL STC-508 [Medical Electronics]

TERUMO INFUSION PUMP MODEL STC-508
Medical Electronics
Principle of Operation

     This unit provides stable, accurate infusion by employing a peristaltic pump equipped with an anti-pulsation mechanism and driven by microcomputer controlled stepping motor.  The unit is provided with the following alarms to ensure safe Infusion.


Alarm name
Function
Alarm Output
Infusion complete
Infusion completes when volume delivered reaches or exceeds the delivery limit.  Subsequently, Infusion continues at the delivery rate of 1ml/h [keep-vein-0pen].  Infusion complete alarm is released automatically when volume delivered becomes less than the delivery limit.
Alarm indication flickers (1.6Hz).  Buzzer continues to sound.  External alarm relay one-shot output.
Start forgotten
When sop position continues for more than w minutes, alarm is output.  Only applicable when the setting of the main PCB DIP SW bit 5 is OFF.
Buzzer sounds intermittently [1.0Hz].  External alarm relay on-shoot output.
Low battery.
Low battery detection circuit detects circuit voltage.  When the voltage of the battery comes down to 9.4Volts or lower, alarm is output. [Switching over to self-diagnosis is mode, voltage A/D value is confirmed.  A/D value 108 or less] alarm judgment is made regardless of infusion operation.  [Alarm is output whether the motor is mot in motion]  Low battery alarm is automatically released when the voltage of the built-in battery is 9.9V or higher.  [A/D value 111 or larger] or line power is connected.  System power source is switched OFF, when the voltage of battery comes down to 8.8V [A/D value 101 or less] (Shut down)
Alarm indication flickers at 1.6Hz.  Buzzer sound intermittently [intervals of buzzing get shorter gradually from 0.5 second to 0.4 second, 0.3 second, 0.2 second, 0.1 second, with the lapse of every minute, thereafter changes to continuous buzzing.  Infusion continues.  External alarm relay one-shot output.  *For methods of switching over to self diagnosis mode and of confirming the voltage A/D value, please refer paragraph 4.2 regarding operation in practice.  Infusion stops.
Air-In-Time
When the Air-In-Time detector senses an air bubble (length inside tubing at least about 5mm) it outputs an alarm.  Alarm judgment is made regardless of infusion.  [Alarm is output whether the motor is not in motion]
Alarm indication flickers [w.6Hz].  Buzzer continues to sound, infusion stops.  External alarm relay one-shot output.
Occlusion
An occlusion detector detects expansion of the tubing, and outputs an alarm when tubing internal pressure reaches 0.5—1.0kg/cm2.  Alarm judgment is made regardless of infusion operation. [Alarm is output whether the motor is not in motion]
Alarm indication flickers [1.6Hz].  Buzzer continues to sound.  Infusion stops.  External alarm relay one-shot output.
Door Open
A door open detector senses whether the door is open or closed.  When the door is open, it output alarm.  Alarm Judgment is made regardless of infusion operation.  [Alarm is output whether the motor is not in motion]
Alarm indication flickers (1.6Hz).  Buzzer continues to sound.  Infusion stops.  External alarm relay one-shot output.
Main CPU Out of Control
When the main CPU goes out of control, the sub CPU detects it and outputs alarm.  Alarm judgment is made regardless of infusion operation [alarm is output whether the motor is not in motion].  To restore the system from out or control situation, switch OFF the source power and then switch ON again.  Main CPU out of control can be checked by self-diagnosis check mode [DIP Sw 8 bit ON]
(Air-In-Line), occlusion door open) Alarm indication lights ON.  ERR6. 7 are indicated.  Buzzer continues to sound.  Infusion stops.  External alarm relay continues to be output.  [One-shot output is not possible]
Sub CPU out of control
When the sub PCB goes out of control the main CPU detects the situation and outputs alarm.  Alarm judgment is made regardless of infusion operation.  [Alarm is output whether the motor is not in motion]  To restore the system from out of control situation to normal, switch OFF the line power and then switch On again.
Alarm indication undefined.  Buzzer continues to; infusion stops.  External alarm relay continues to be output (one-shot output is not possible).
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TROUBLESHOOTING CHART: TERUMO INFUSION PUMP: STC – 508 [MEDICAL ELECTRONICS]

Part-3


27
  1. Membrane sheet SW defective.
  2. Causes other than above
  1. The switch is defective if: NO-5 and No-7 pins of sub PCB connector (CN-1) does not short circuit when purge switch is pressed, or short circuit status exists before pressing the switch.
  2. Various check
  1. Replace panel part.
  2. Ref: Item No-5.
28
  1. Membrane sheet switch defective.
  2. Sub PCb connector: CN-1 defective.
  3. Sub PCB defective.
  4. LCD defective.
  1. The switch id defective if: No-4 and No-8 pins of sub PCB connector (CN-1) does not short circuit when setting change-over SW is pressed.  Or  short-circuit status exists before pressing the SW.
  2. Check connector.
  3. If not withstanding sheet SW normalcy signal does not generate on NO-1-22 pins and 69-80 pins of sub CPU, the sun CPU is defective.
  4. Display is un available or un reliable.
  1. Replace the panel part.
  2. Check connector function (*9)
  3. Replace sub PCB.
  4. Replace sub PCB.
31
1. maximum discharge pressure adjusting mechanism defective.
1. If delivery limit on test is less than 98ml or more than 103ml, adjustment is improper.
1. Re-adjust pressure.  Compensate delivery rate.  (replace seal packing, if degenerate)
33
1         connector (CN-8),external connection connector defective.
2         Cable defective.
3         External alarm relay output circuit defective.
4         External alarm relay defective.
5         Main CPU defective.
  1. check connector.
  2. Check cable.
  3. If No-8 pin of relay (RL-2) does not take “L” level, the circuit id defective.
  4. If, not withstanding No-8 pin of relay (RL-20 TAKING “L” level, short circuit between No-3 and No-4 pins of CN-8 does not take place, the relay is defective.
  5. If No-61 pin of main CPU does not output “H” level, the main CPU is defective
  1. check connector function. (*9)
  2. Replace cable.
  3. Replace main PCB.
  4. Replace main PCB.
  5. Replace main PCB.
34
  1. Connector [CN-8 external connection connector defective.
  2. Cable defective.
  3. Defective external alarm one-shot input circuit.
  4. Main CPU defective.
  1. Check connector.
  2. Check cable.
  3. If not withstanding II level of CN-8 NO-7 pin NO-45 pin of CPU does not take “L” level, the circuit is defective.
  4. If notwithstanding “L” level of main CPU No-45 pin, relay one-shot is not output, main CPU is defective.
  1. Check connection function.
  2. Replace cable.
  3. Replace main PCB.
  4. Replace amin PCB.
35
  1. Connector CN-8 external connection.
  2. Cable defective
  3. Defect of external alarm buzzer cancel signal input circuit.
  4. Main CPU defective
  1. Check connector.
  2. Check cable
  3. If, notwithstanding “L” level of CN-8 No-5 pin NO-44 pin of CPU does not take ‘H” level, the circuit is defective.
  4. If notwithstanding “H” level of of main CPU No-44 pin, buzzer does not stop, main CPU is defective.
1.Check connector function.
  1. Replace cable.
  2. Replace main PCB.
  3. Replace main PCB.

37
  1. Occulusion pressure adjustment defective.

1.  If occlusion pressure is less than 0.5kg/cm2 or more than 1.0kg/cm2
1.  Adjust occlusion detection pressure.
38
  1. Defect of low battery A/D signal generating circuit.
  2. Main CPU decetive.
  1. low battery alarm is not output.
  2. Confirm voltate A/D value in the self diagnosis mode.  If low battery alarm is not generated, even when A/D value is less thatn 108, main CPU is defective.
1 Replace main PCB.
Replace main PCB.
39
1. Main Cpu defective.
1  Source power shutdown does not take place.  Confirm voltage A/D value in the sef diagnosis mode.  If source power shutdown does not take place even A/D value is les than 101, main CPU is defective.
1.  Replace main PCB.  For the method of changing the mode into self diagnosis and confirming voltage A/D value, refer paragraph 4.2
40
  1. power source connection defective.
  2. Other than above
  1. Connect power source twice or thrice times.
  2. Refer the paragraph-2
  1. Connect power line tightly.
  2. Refer the paragraph 2.
41
  1. Battery defective.
  2. Other than above.
  1. Battery LED does not light.
  2. Refer to paragraph-2
  1. Replace battery.
  2. Refer to paragraph-2
42
  1. Battery defective.
  2. Other than above.
  1. Alarm light
  2. Refer paragraph -2
  1. Replace battery.
  2. Refer paragraph-2.





END. 
Principles of operation to Terumo Infusion Pump Model-508 follows on next blog
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Wednesday, January 25, 2012

TROUBLESHOOTING CHART: TERUMO INFUSION PUMP: STC – 508 [MEDICAL ELECTRONICS]

PART-2


10
  1. Sub PCB connector: CN-1 defective.
  2. Cable defective.
  3. Membrane sheet SW defective.
  4. Defective of source power SW disconnection detection circuit.
  5. Sub CPU defective.
Err 9 is displayed.
  1. Check connector.
  2. Check cable.
  3. Membrane SW is damaged when No-6 and No-10 pins of CN-1 of PCB are continuously in short circuit.
  4. Circuit is defective when: Output from No-42 pin of sub CPU continues on H level, despite membrane SW is normal.
  5. Other than the above.
  1. Check connection function.
  2. Replace cable.
  3. Replace membrane sheet SW.
  4. Replace sub PCB.
  5. Replace sub PCB.

11
  1. main PCB connector: CN-7 defective.
  2. Main PCB defective.
  1. Check connector.
  2. Other that the above.
  1. Check connection function.
  2. Replace main PCB.
12
  1. Circuit defective of backlight LED, LCD, LED, main/sub CPU, LED drive, etc.
  2. Buzzer circuit defective.
  1. Visual check [check if any non-light items]
  2. Buzzer does not sound.
  1. Replace the sub PCB.
  2. Replace main PCB. [Ref: item No-18]
15
  1. Main pcb connector [CN-4] defective.
  2. Cable defective.
  3. Door open detection sensor defective.
  4. Door open detection circuit defective.
  5. Main CPU defective.
  1. Check connector.
  2. Check cable.
  3. While door is open, if CN-4 8-9P is short circuit; the sensor is defective.
  4. While door is open, if L level signal is output fron No-8 pin of IC-12 of door open detection circuit, the circuit is defective.
  5. While door is open, if L level signal is output to No-10 pin of CPU (IC-1), main CPU is defective.
  1. Check connector function.
  2. Replace cable.
  3. Replace door open detection sensor.
  4. Replace main PCB.
  5. Replace main PCB.
16
  1. Source power judging circuit defective.
  2. Transformer defective.
  3. Fuse blown [inside main PCB]
  4. Main CPU defective.
  5. Main PCB connector.
  6. Cable defective
  7. Sub-CPU defective
  8. LED drive circuit defective.
  9. LED defective.
  1. If voltage between collector and emitter of transistor [TR-4] is more than 1 volt, the circuit is defective.
  2. If 13.8VAC voltage is not measured between No-4 and No-6 pins of CN-9, the transformer is defective.
  3. Check fuse [ICP2] and [ICP5] by applying tester bridging 2 ends of each fuse.
  4. Cases by other cause.
  5. Check connector.
  6. Check cable.
  7. If No-35 pin of sub CPU does not output II level signal, sub CPU is defective.
  8. If No-15 pin of IC [4A] in LED drive circuit of sub PCB does not output L level, the circuit is defective.
  9. If voltage between the two end of resistor [R2] is about (0V) or about (12V), the LED is defective.
  1. Replace main PCB.
  2. Replace transformer.
  3. Replace main PCB.
  4. Replace main PCB.
  5. Check connector function.
  6. Replace cable.
  7. Replace sub PCB.
  8. Replace sub PCB
  9. Replace sub PCB.
17
  1. Sub CPU defective.
  2. LCD defective
  3. LED drive circuit defective.
  4. LED defective
  1. Check if output signal to sub CPU LCD is normal
  2. Check the input signal to sub CPU LCD is normal.
  3. If No.10 pin of IC (3C) in LED drive circuit of sub PCB does not output “L” level, the circuit is defective.
  4. If voltage between the two ends of resistance (R2) is about (0V) or about 12V, the LED is defective.
  1. Replace sub PCB.
  2. Replace sub PCB.
  3. Replace sub PCB.
  4. Replace sub PCB.
18
  1. Main CPU defective
  2. Buzzer drive circuit defective
  3. Buzzer defective.
  1. If No 20. pin of main CPU does not output “L” level signal, or NO 62P does not output pulse signal, the main CPU is defective.
  2. Defective buzzer source power supply.  If about 2.048KHz oscillation is not transmitted from NO-3 pin of IC 13 in buzzer drive circuit of main PCB, the circuit is defective.    If the collector and emitter of transistor TR-6 in the buzzer drive circuit does not repeat )N_OFF between them, in synchronized with pulse signal output from No-62 pin of main CPU, then the circuit is defective.    If No-8 pin of IC-11 in buzzer drive circuit does not output ‘H” level signal, the circuit is defective.    If NO-11 pin of IC-11 in buzzer dirvie circuit does not repeat ON_OFF, synchronized with pulse signal output from No-# pin of IC-13, then the circuit is defective.
  3. Cases by other cause
  1. Replace main PCB.  No more repair to this board can be done.
  2. Replace main PCB
  3. Replace main PCB
27
  1. Membrane sheet SW defective.
  2. Causes other thatn above
  1. The switch is defective if: NO-5 and No-7 pins of sub PCB connector (CN-1) does not short circuit when purge switch is pressed, or short circuit status exists before pressing the switch.
  2. Various check
  1. Replace panel part.
  2. Ref: Item No-5.

To be continued Part-3

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