MICROPROCESSOR DIAGNOSTICS/Differnces beteween TK/CTC

Microprocessor Diagnostics
Diagnostics are the microprocessor’s ability to perform internal and external control system self checks to verify unit performance.

Thermo King Pretrip (mP-IV+ Smart Reefer, mP-V Whisper)
A Full Pretrip Test will check the current draw of control devices connected to the microprocessor to determine that they are connected and are drawing the proper amount of current. The unit is then started (may be automatic or manual). The microprocessor controller displays all icons, programmable settings and checks engine speed. Refrigeration capacity is checked in both cool and heat modes by monitoring temperature differential and comparing to a standard. Units equipped with modulation are checked to be sure the modulation valve opens and closes. A Defrost check is performed and the unit's status is reported as PASS, CHEC or FAIL. If any problems are encountered the appropriate alarm code(s) will be saved. The Pretrip Test results will remain on the display until any keypad key is pressed.

Thermo King Unit Self Check (TG-VI Max+)
The Unit Self Check performs a display check and then displays all programmable settings. An RPM check and defrost damper check are next. Last, a check is performed to insure the unit can cool and heat by monitoring the rise and/or fall of the coil temperature sensor and comparing to a standard. Units equipped with modulation are checked to be sure the modulation valve opens and closes. If any problems are encountered the appropriate alarm code(s) will be saved. The results are then reported as PASS, CHEC or FAIL. The Unit Self Check results will remain on the display until any keypad key is pressed.

Carrier (Ultra and Ultima)
The unit Pretrip is initiated by depressing the Pretrip key. The trailer box temperature must be below 40°F. The controller will display “PPPP” and the unit will operate in each of the six modes of operation for a period of 30 seconds each. The unit will then enter the defrost mode and terminate the Pretrip once the defrost termination switch opens at approximately 50°F (10°C). The operator must monitor the progress of the test and record any malfunctions.


SAVED ALARMS
If a fault condition is detected the microprocessor will generate and save the appropriate Alarm Code.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
The Thermo King trailer microprocessors utilizes three levels of alarm codes Stored, Check and Shutdown. The mP-IV+ Smart Reefer microprocessor has 59 separate alarm codes and the mP-V Whisper has 61 separate alarm codes which are saved until each is individually cleared using the Code and Clear keys.

Thermo King TG-VI Max+
The Thermo King trailer microprocessors utilizes three levels of alarm codes Stored, Check and Shutdown. The TG-VI Max+ microprocessor has 42 separate alarm codes which are saved until each is individually cleared using the Select and Enter keys.

Carrier Ultra and Ultima
The Carrier microprocessor has two levels of alarm codes, Check and Shutdown. There are 23 individual codes which are cleared by either by turning the unit power switch off and on or by using the Clear Code Screen.

ALERT SYSTEM
The microprocessor monitors the temperature sensors and checks for conditions that may be out of tolerance.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
The Alert system monitors the temperature differential and compares it to defined values of temperature differential as determined by setpoint and/or ambient temperature. If the temperature differential over a period of time indicates the possibility of reduced refrigeration performance a check alarm is generated. If the condition continues to exist over an additional period of time a shutdown alarm may occur. If over a period of time the unit is heating when it should be cooling or cooling when it should be heating a shutdown alarm will be generated.

Carrier Ultra and Ultima
When the Out of Range feature is turned on the controller indicates an out of range condition if the temperature has been in the temperature range band once and then goes outside the range band for 45 minutes. The unit will then shut down and indicate an alarm. When the Out of Range feature is turned off and the same conditions exist as above for 15 minutes the unit will indicate an out of range alarm but continue to operate.


CYCLE SENTRY
Cycle Sentry automatically starts and stops the unit as required by box temperature and other conditions.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
When selected, Cycle Sentry mode automatically starts unit operation when cooling, heating or defrosting is necessary and stops unit operation when the temperature reaches setpoint. The unit will continue to start and stop as required to maintain the setpoint. In addition, if diesel mode is selected, Cycle Sentry will automatically start and stop the engine as required to maintain engine coolant temperature to assure quick starts. If the engine coolant temperature falls below 30°F (-1°C) and Diesel Cycle Sentry is selected the engine will start and run until the coolant temperature is above 90°F (32°C).

Carrier Ultra and Ultima
When selected, Auto Start/Stop mode automatically starts unit operation when cooling, heating or defrosting is necessary and stops unit operation when the temperature nears setpoint. The unit will continue to start and stop as required to maintain the setpoint. Unit shutdown is allowed only if the battery condition signal is good. Engine coolant temperature will override the minimum off time and out-of-range condition and start the engine when the engine coolant temperature drops below 34°F (1°C). A restart will also be initiated if the battery voltage falls below 11.0 volts. On certain software revisions the minimum off time setting will be overridden to initiate a restart if the box temperature rises 11°F (6°C) above the setpoint.

CYCLE SENTRY AMPS
The microprocessor will run the unit to charge the battery as necessary even after box temperature is satisfied.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
When operating in the Cycle Sentry mode the engine will continue to run to charge the battery until the charging current falls below a pre-set limit, even if the temperature requirements are satisfied. The Cycle Sentry Amperes limit is programmable from 2 to 8 amperes in 1 ampere increments. The standard setting is 5 amperes.

Thermo King TG-VI Max+
N/A

Carrier Ultra and Ultima
N/A


CYCLE SENTRY BATTERY SENTRY
The microprocessor monitors battery voltage during null periods and starts and stops the diesel engine as necessary to keep the unit battery charged.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
When operating in the Diesel Cycle Sentry mode the microprocessor will monitor battery voltage in null periods and will start the unit if the battery voltage falls below a pre-set limit, even if the unit does not require cooling or heating. This Cycle Sentry Battery Voltage limit is programmable from 11.8 to 12.6 volts in 0.1 volt increments. The standard setting is 12.2 volts. The engine will continue to run to charge the battery until the charging current falls below a pre-set limit of between 2 to 8 amps and no other running requirements exist.

Thermo King TG-VI Max+
When operating in the Diesel Cycle Sentry mode the microprocessor will monitor battery voltage in null periods and will start the unit if the battery voltage falls below a pre-set limit, even if the unit does not require cooling or heating. This Cycle Sentry Battery Voltage limit is preset at 12.2 volts. The engine will continue to run until the battery voltage exceeds a pre-set limit of 13.6 volts for 7 minutes and no other running requirements exist. This time will automatically increase if additional battery restarts are required.

Carrier Ultra and Ultima
When operating in the Start/Stop mode the microprocessor will monitor battery voltage in null periods and will start the unit if the battery voltage falls below 11 volts, even if the unit does not require cooling or heating. The engine will continue to run until the battery voltage exceeds a pre-set limit of 13.4 volts and no other running requirements exist.


CYCLE SENTRY FRESH RANGE
Allows Cycle Sentry operation to be locked out within a programmable temperature range.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
The Cycle Sentry Fresh Range feature allows the microprocessor to be programmed to operate the unit only in Continuous mode within a selected temperature range above the Fresh/Frozen setting. This is useful with loads that benefit from continuous air circulation provided by Continuous mode operation.

Thermo King TG-VI
N/A

Carrier Ultra and Ultima
Carrier units with certain software revisions can be configured to lockout the start/stop mode from 32°F (0°C) to 42°F (5.5°C). The Start/Stop/Continuous run switch is disabled in this temperature range.


PROGRAMMABLE HOUR METERS
Programmable hourmeters are provided.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
Thermo King units offer 3 programmable hourmeters. Programmable hourmeters can be set to record a number of different maintenance or performance intervals.

Carrier Ultra and Ultima
Carrier units offer 2 programmable hourmeters to record maintenance intervals.


AMPS DISPLAY
Microprocessor displays current flow to or from the unit’s battery.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
The microprocessor displays the rate of current flow to or from the unit’s battery. This feature is also used for amp checks during the Pre-trip Test, Cycle Sentry Amps to maintain the battery in a charged condition and to monitor other operating conditions.

Thermo King TG-VI
N/A

Carrier Ultra and Ultima
Carrier units are equipped with a standard analog ammeter located inside the engine compartment. The ammeter is not utilized by the microprocessor.


OIL PRESSURE DISPLAY
Microprocessor displays engine oil pressure.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
The microprocessor displays the engine oil pressure
Carrier Ultra and Ultima
N/A

WATER TEMPERATURE DISPLAY
Microprocessor displays the engine coolant temperature. This information is also used for prevent shutdowns

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
The microprocessor displays the engine coolant temperature.

Carrier Ultra and Ultima
The microprocessor displays the engine coolant temperature.


SPARE TEMPERATURE SENSORS
The microprocessor can display and record extra temperature sensors. The number of sensors available depends on the application.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
The microprocessor can display and record two spare sensors.

Thermo King TG-VI Max+
N/A

Carrier Ultra and Ultima
The microprocessor can display and record one spare sensor.


DEFROST AIR SWITCH
A defrost air switch compares the pressure difference from one side of the evaporator coil to the other. An increasing pressure differential indicates frost or ice and initiates a defrost cycle.

Thermo King mP-V Whisper
N/A

Thermo King mP-IV+ Smart Reefer,
Standard

Thermo King TG-VI Max+
N/A

Carrier Ultra and Ultima
Standard


FIXED DEFROST TIMERS
Defrost timers are used as one method of initiating a defrost cycle.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Two defrost timers are used. When the unit is In-Range defrost intervals are controlled by the Defrost Interval In-Range timer. This timer can be set for 4, 6, 8 or 12 hours. When the unit is not in range, defrost intervals are determined by the Defrost Interval Not In-Range timer. This timer can be set for 2, 4, 6, 8 or 12 hours. This feature allows a shorter defrost time to be used when the unit is out of range such as during pulldown and more frequent defrost cycles may be beneficial. Demand Defrost is also available.

Thermo King TG-VI Max+
Initial defrost time is adjustable either 2, 4, or 6 hours. Additional Smart Defrost cycles are controlled by the microprocessor. Demand Defrost is also available.

Carrier Ultra and Ultima
One timer that is adjustable either to 1.5, 3, 6 or 12 hours.

SMART DEFROST
After the first defrost cycle the unit will enter a defrost cycle based on amount of time required to complete the previous defrost cycles. This interval may be longer or shorter than the time set above.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
N/A

Thermo King TG-VI Max+
Standard

Carrier Ultra and Ultima
N/A


DEMAND DEFROST
Return air temperature, discharge air temperature and evaporator coil temperature is monitored. A demand defrost cycle is initiated if the temperature differential begins to increase and the coil is cold enough to indicate the possibility of frost or ice.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
Standard on all Units

Carrier Ultra and Ultima
N/A


MODULATION
A modulation valve capable of opening and closing incrementally is installed in the suction line. As the temperature approaches setpoint, the modulation valve begins to close, throttling the suction gas returning to the compressor and thus reducing cooling capacity. This feature provides very smooth and steady temperature control and reduces top freeze, product shrinkage and dehydration. Modulation is only operational in Continuous mode.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
Optional on all models

Carrier Ultra and Ultima
N/A - Thermo King exclusive

MODULATION RANGE
Modulation can be set to operate in a defined setpoint range from that established by Fresh/Frozen Range to that established by Setpoint Limit High. The feature can also be deactivated if necessary.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Included with Modulation option

Thermo King TG-VI Max+
N/A

Carrier
N/A


ULTRA FRESH 2
UltraFresh 2 temperature control is a method of producing a reduced capacity state by combining a null pulse with either the heat or cool mode. This feature is operational only in the Continuous Run mode at setpoints above 10°F (-12°C).

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
N/A - Carrier exclusive.

Carrier and Ultima
Carrier Ultra - Optional
Carrier Ultima - Standard


HIGH SPEED PULL DOWN
High speed pulldown to setpoint when the unit is first started.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
Programmable on all units

Carrier Ultra and Ultima
Standard on all units

LOW SPEED START
The unit will start in low speed on initial startup.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
The unit will automatically start in low speed as long as the engine temperature is less than 50°F (10°C). The unit will operate in low speed for 2 minutes on initial startup. It will continue to operate in low speed until the engine coolant reaches a temperature of 90°F (32°C).

Thermo King TG-VI Max+
The unit will start in low speed as long as the engine temperature is less than 50°F (10°C). The unit will operate in low speed for 2 minutes on initial startup. It will continue to operate in low speed until the engine coolant reaches a temperature of 90°F (32°C).Programmable On or Off.

Carrier Ultra and Ultima
Both models will start and run in Low Speed for the first 15 seconds. Once the engine coolant temperature rises above 79°F the microprocessor will allow the unit to operate as normal.

Note: On Carrier units equipped with software 3.11 or higher the unit will remain in low speed for 10 minutes after engine start-up when: Auto Start/Stop is at any setpoint or Continuos Run setpoint is below 10°F (-12°C).


FUEL SHUTDOWN
The Fuel System Shutdown senses an out of fuel condition. This will prevent the need for priming the fuel pump and/or bleeding the fuel lines.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Standard

Thermo King TG-VI Max+
Optional as a Service part kit

Carrier Ultra and Ultima
Optional

AIR FLOW DETECTION
The Airflow Detect feature compares the Return Air and Discharge Air temperatures. If these temperatures follow each other closely it is assumed that the unit may be short cycling due to restricted air flow. This can be caused by improper loading or by the load shifting during transport.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Standard

Thermo King TG-VI Max+
N/A

Carrier Ultra and Ultima
N/A


SLEEP MODE
Sleep Mode does not maintain the setpoint during Sleep Mode operation, it only keeps the diesel engine warm and the unit battery in a charged condition. This is useful in extremely cold weather or if the unit is to be out of service for some period of time. If the unit is equipped with a data logger, the programmable Sleep Mode Exit Time is also available. The unit can be programmed to wake up when the Exit Time and Date is reached. The unit will then exit Sleep Mode, perform a Full Pretrip test and resume operation in normal Cycle Sentry mode, controlling to the selected setpoint. Sleep Mode can be deactivated at any time by turning the unit On/Off switch off.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Standard

TG-VI
N/A

Carrier
N/A


SLEEP MODE SWITCH
Allows the unit to be placed in Sleep Mode with a single switch.

Thermo King mP-V Whisper
Optional

Thermo King mP-IV+ Smart Reefer, TG-VI Max+
N/A

Carrier
N/A
FRESH/FROZEN RANGE SELECT
The microprocessor uses one set of control specifications when operating in the "Fresh" range and a second set of control specifications when operating in the "Frozen" (heat lockout) range. Fresh/Frozen Range Select allows the line between "Fresh" and "Frozen" range to be programmed to either 24°F (-4°C) or 15°F (-9°C).

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Standard

Thermo King TG-VI Max+
N/A

Carrier
N/A


PREVENT SHUTDOWN
The microprocessor will reduce the engine speed and/or load in an attempt to continue to operate the unit under certain conditions. If conditions continue to exist the unit will shut down.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Standard

Thermo King TG-VI Max+
N/A

Carrier Ultra and Ultima
N/A


MAX NULL TIME LIMIT
Maximum Null Time Limit can be used to insure air flow in Cycle Sentry mode operation. If the unit remains in null for an extended period the engine will start to provide airflow even though unit demands do not require a restart.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Standard - Programmable to OFF, 20, 40 or 60 minute intervals.

Thermo King TG-VI Max+
N/A

Carrier Ultra and Ultima
Standard - When setting microprocessor to Time Start ON, unit will restart in 30 minutes.

NULL LIMIT FROZEN RANGE
When the unit is operating in Cycle Sentry mode in the frozen range the unit will enter Null mode at setpoint. The Cycle Sentry Null Frozen Range allows the range above setpoint for Cycle Sentry restarts to be adjusted from 5 to 20°F (3 to 11°C). In addition, the unit will maintain an upper limit of 29°F (-2°C).

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Standard

Thermo King TG-VI Max+
N/A

Carrier Ultra and Ultima
N/A


SETPOINT LIMIT HIGH
The Setpoint Limit High allows the upper setpoint limit to be set to a maximum of 90°F (32°C) in one degree increments. The minimum setting available is determined by the setting of Setpoint Limit Low.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
Standard

Carrier Ultra and Ultima
N/A


SETPOINT LIMIT LOW
The Setpoint Limit Low allows the lower setpoint limit to be set to a minimum of -20°F (-29°C) in one degree increments. The maximum setting available is determined by the setting of Setpoint Limit High.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
Standard

Carrier Ultra and Ultima
N/A

SERVICE TEST MODE
The Service Test Mode allows the unit to be forced to a known operating mode. This allows service personnel to troubleshoot the system under defined conditions. All function keys and unit protection features remain active in Service Test Mode.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
Standard

Carrier Ultra and Ultima
Optional and requires laptop computer


RELAY BOARD TEST MODE
The Relay Board Test Mode allows each relay or output to be momentarily forced on or locked on. The preheat and start relays can only be momentarily energized.

Thermo King mP-V Whisper
Standard

Thermo King mP-IV+ Smart Reefer
Standard in most versions of software

Thermo King TG-VI Max+,,
Standard

Carrier Ultra and Ultima
Optional and requires laptop computer


SINGLE ON/OFF SWITCH
The unit is turned on and off with a single switch. Engine starts are automatic in both Cycle Sentry and Continuous mode.

Thermo King mP-V Whisper
Standard

Thermo King mP-IV+ Smart Reefer
N/A

Thermo King TG-VI Max+
Standard

Carrier
Standard

AUTO START IN CONTINUOUS
The engine starts automatically in both Cycle Sentry and Continuous Mode operation.

Thermo King mP-V Whisper
Standard

Thermo King mP-IV+ Smart Reefer
N/A

Thermo King TG-VI Max+
Standard

Carrier
Standard


AUTOMATIC RESTARTS
The microprocessor will restart the unit following a shutdown alarm. If the condition continues to reoccur the unit will remain shut down.

Thermo King mP-V Whisper
Engine restarts will occur after detection of the following Alarm Codes: 9, 10, 17, 18, 19, 20, 23, 24, 35, 44 and 63. If these Codes are detected the unit will restart after a time interval to continue to provide load protection.

Thermo King mP-IV+ Smart Reefer
N/A

Thermo King TG-VI Max+
N/A

Carrier
Standard - An engine restart will occur after detection of the following Alarm Code: HI PRESS
Note: HI PRESS (compressor high discharge pressure) is also used for compressor low suction pressure.

REMOTE CONTROL
Allows trailer units to be controlled from inside the trailer and truck units to be controlled from inside the cab.

Thermo King mP-V Whisper
Optional

Thermo King mP-IV+ Smart Reefer
N/A

Thermo King TG-VI Max+
Optional

Carrier
N/A


DOOR SWITCH
The door switch can be used for data logger recording only or to shut the unit down when the trailer door is opened.

Thermo King mP-IV+ Smart Reefer and mP-V Whisper
Optional with add-on kit.

Thermo King TG-VI Max+
Optional with add-on kit - shutdown feature only.

Carrier
Optional with add-on kit.


High Air Flow
Programmable on the microprocessor for either normal or high air flow. When high air flow is selected the unit is locked into high speed.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
N/A

Carrier Ultra and Ultima
Standard - programmable

Minimum Off Time
When selected, this feature allows the unit to re-start based on time rather than temperature.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
N/A - Restart is based on temperature demand

Carrier
Ultra units - Programmable to 10,20,30,45 or 90 minutes. If the box temperature rises above 11F the processor will overide the time setting and re-start.
Ultima units - Re-start is based on time then temperature.


Minimum On Time
When the unit re-starts in the Start/Stop mode the unit has to run for a minimum time.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
N/A - On time is based on box temperature, battery condition and/or engine temperature.

Carrier Ultra and Ultima
Ultima - Runs for a minimum of 4 minutes.
Ultra- Programmable for a minimum of 4 or 7 minutes.


Programmable Graded Sensors
Sensors are graded for accuracy and require no calibration.

Thermo King TG-VI Max+, mP-IV+ Smart Reefer, mP-V Whisper
Standard

Carrier Ultra and Ultima
N/A

COMMUNICATION PORTS
The ability to communicate with an external device via a serial port in addition to the usual data logger connection. They can be used to connect satellite electronics, remote controls and other future equipment. It is also used to perform factory tests on each unit.

Thermo King mP-V Whisper
Standard

Thermo King mP-IV+ Smart Reefer
Only on units with optional Data Logger

Thermo King TG-VI Max+
Standard

Carrier Ultra and Ultima
Standard


INTERVAL DATA LOGGING
Temperature sensor readings and major operating conditions such as unit on/off and operating mode are recorded at programmable intervals.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Optional

Thermo King TG-VI Max+
N/A

Carrier Ultra and Ultima
Optional


EVENT DATA LOGGING
Event data logging records nearly every operating event that occurs at the exact time that each event occurs.

Thermo King mP-IV+ Smart Reefer, mP-V Whisper
Optional

Thermo King TG-VI Max+
N/A

Carrier Ultra and Ultima
Optional


Regards R-T

R-T, once again, thanks for sharing this useful comparison sheet with all who may have transport temp control equipment or a background in servicing those.

regards
T-P

Yeah that is a whole wack of good solid info, Cant wait for more of this stuff.;)

Regards A-Z

Quote:

---

Originally Posted by absolute-zero

Yeah that is a whole wack of good solid info, Cant wait for more of this stuff.;)

Regards A-Z

---

Steady A-Z, talking to yourself can be life changing - you get funny looks from those around you. :D:D;)

How you been Brian?

I am used to the funny looks, I have reread all the rules again "word for word", so no worries mate, they will be followed here on out. I really do like coming here and offering some tech advise. That is all i will bring to this forum if its all the same to you.

Regards A-Z

hi evry bady
can you help me to send some catallogues for reefer trauck .
monir_khatibi@hotmail.com

hi
can you help me to send some catallogues for reefer trauck my mail: sam_virgo_123@hotmail.com

i want to learn more and more with my senior's reefer technician....Gob Bless and more power

Hi Fellas,
First time posting on a thread, but I enjoy reading your comments and I am learning a whole lot from you fellas. Thank you all.
I serviced a thermoking smart reefer, model CRR40, year 1998, controler MP3000, uses a 7.5hp copeland discus with R134a. I keep getting error 18 (power supply phase error), and error 36 (current too high). I checked the power supply and it's ok (415v-422v, 10-14 amps @ 50hz). but when I check the up read out it's way out (565.5v and 24.5 amp on 3 leg). The unit does not shutdown and works fine otherwise.
Can someone suggest a fix without changing the relay board?

hi
I have a big problem with thermoking SB-III SR+ and microprocessor mP-IV. it shows no. 71 codes and all temperature begin fluctuation help me plz

code 71 just means its due for a service, does not affect operation.
press the alarm button a few times to see all alarms

Quote:

---

Originally Posted by bolandhemat

hi
I have a big problem with thermoking SB-III SR+ and microprocessor mP-IV. it shows no. 71 codes and all temperature begin fluctuation help me plz

---

Temperature fluctuation is most likely can be corrected by cleaning the micro processor connections. Use dielectric grease on the connections after cleaning with electronic cleaner.

Thanks a lot for sharing this infor. Happy to join this forum!!!!!!