Multimeter (Vc88c) Reading Temperature Wrong

[dark phobia]

I broke my multimeter(Vİctor Vc88c). Everything is working charm except temperature. Multimeter display wrong temp. Like -250℃. I am not measure temp often but i want to repair if its possible.
So I didn't find my multimeter scheme on the internet. I found two multimeter that has similar technical properties. I think vc9805a and ut70a are look like my multimeter. And ut70a inside looked very similar to me. What might be the problem? I want to know which part of the schemes are related with temperature measurement. Need help. Thankyou...

Victor VC88C 3 1/2 Digital Multimeter

FEATURES
·New type holster, stream
line design
·Large LCD makes the reading clearly.
·Metallic screen board with stronger antimagnetic and anti-interferential function.
·No power off under natural operation.
·Full function protection, anti-high voltage circuit design.

Basic Function Range Basic accuracy
DC Voltage 200mV/2V/20V/200V/1000V ±(0.5%+3)
AC Voltage 2V/20V/200V/750V 　
200mV/2V/20V/200V/750V ±(0.8%+5)
DC Current 20uA/200uA/20mA/200mA/2A/20A 　
20mA/200mA/20A 　
2mA/20mA/200mA/20A ±(0.8%+3)
AC Current 200mA/2A/20A 　
20mA/200mA/20A 　
2mA/20mA/200mA/20A ±(1.0%+5)
Resistance 200Ω/2kΩ/20kΩ/200kΩ/2MΩ/200MΩ 　
200Ω/2kΩ/20kΩ/200kΩ/2MΩ/20MΩ/2000MΩ ±(0.8%+3)
Capacitance 20nF/2uF/200uF 　
20nF/200nF/2uF/20uF/200uF ±(2.5%+20)
Frequency 2kHz/200kHz 　
2kHz/20kHz/200kHz/2000kHz/10MHz ±(0.5%+4)
Inductance 2mH/20mH/200mH/2H/20H ±(2.5%+20)
Celsius (-40~1000)℃ ±(1.0%+4)

Special Function
Diode test √
Continuity buzzer √
Low battery indication √
Data Hold √
Auto power off √
Backlight √
Function protection √
Restorable Fuse protection √
Shock proof protection √
Input impedance 10МΩ
Sampling rate 3 times/s
AC Frequency response 40~400Hz
Operation way Manual range
Max. Display 1999
LCD size 65×45mm
Battery 9V(6F22)

VC9805A+ 3-1/2 Digital Multimeter

Detail:
·New type hols
ter, streamline design.
·Large LCD makes the reading clearly.
·Metallic screen board with stronger antimagnetic and anti-interferential function.
·No power off under natural operation.
·Full function protection, anti-high voltage circuit design.
·New type battery case design, it’s easy to change battery.
Basic Function
Range
Accuracy
DC Voltage
200mV/2V/20V/200V/1000V±(0.5%+3)
AC Voltage200mV/2V/20V/200V/750V±(0.8%+5)
DC Current2mA/20mA/200mA/20A±(0.8%+10)
AC Current2mA/20mA/200mA/20A±(1.0%+15)
Resistance200Ω/2kΩ/20kΩ/200kΩ/2MΩ/20MΩ±(0.8%+3)
Inductance2mH/20mH/200mH/2H/20H±(2.5%+30)
Capacitance20nF/200nF/2uF/20uF/200uF±(2.5%+20)
Frequency2kHz/20kHz/200kHz/2000kHz/10MHz±(3.0%+18)
Celsius(-40~1000)ºC±(1.0%+5)
Fahrenheit(0~1832)ºF±(0.75%+5)


Special Function

Diode√
Transistor test√
Continuity buzzer√
Low battery indication√
Hold
Data hold
Auto power off√
Backlight√
Function protection√
Shockproof protection√
Input impedance10MΩ
Sampling rate3 times/s
AC Frequency response40~400Hz
Operation way Manual range
Max. Display1999
LCD size70×50mm
Battery9V (6F22)
Product color
Case: dark gray; Holster color: yellow
Product Net Weight
Approx:320g
Product Dimension
190×88.5×27.5mm
Standard Accessories
Test leads, battery, instruction manual, TP01
temperature probe (with temperature function)
Standard inner packing
Color box


UNI-T UT70A

SPECIFICATIONS
Basic Functions Range Best Accuracy
DC Voltage 200mV/2V/20V/200V/1000V

(0.5%+1)
AC Voltage 200mV/2V/20V/200V/750V

(0.8%+3)
DC Current 20mA/2mA/200mA/10A

(0.8%+1)
AC Current 20mA/2mA/200mA/10A

(1%+3)
Resistance 200W/2kW/20kW/200kW/2MW/20MW/2000MW

(0.8%+1)
Capacitance 20nF/200nF/ 2mF/100mF

(2.5%+5)
Temperture(°C) -40°C~1000°C

(1%+3)
Temperture(°F) -40°F~1832°F

(1%+4)
Frequency 2kHz -10MHz(Auto Ranging)

(0.1%+3)
Inductance 2mH/20mH/200mH/20H

(2%+10)
Logic TTL (High > 2.0V, Low < 0.8)

Special Functions
Fused 10A Range

Diode

Continuity Buzzer

Transistor

Peak Hold

Data Hold

Display Backlight

Full Icon Display

Sleep Mode

Low Battery Display

Max. Display 1999

GENERAL CHARACTERISTICS
Power 9V Battery (6F22)
LCD Size 62 x 53mm
Product Colour UT70A - Grey, Holster - Red
Product Net Weight 620g (including holster)
Product Size 195 x 90 x 40mm
Standard Accessories Test Lead, Battery, English Manual, Point Contact Temperature Probe, Test Clip, Multi-Purpose Socket, Holster
Optional Accessories* Clip-On Test Lead Light (UT-TL), Built-In Test Lead Light (UT-L1), Built-In Test Lead Light Plus (UT-L2), Carrying Bag
Standard Packing Gift Box
Standard Quantity Per Carton 20 pcs
Standard Carton Measurement 535 x 365 x 380mm (Around 0.074 CBM Per Standard Carton)
Standard Carton Gross Weight 22.7kg

 

[KrisBlueNZ]

It looks like the temperature probe connects through the µA/mA connector. Check that the fuse on that connector is not blown. I have no other suggestions.

 

[dark phobia]

I have only this multimeter so i can't measure. I calibrated the temperature vr5 and vr6 -320℃ at room. I measured hot water as 397℃. Multimeter working reverse but i think it is enough.

When i connect to 1k ohm resistor to R17 reading temperature is get better and display +30℃. I have no smd resistor now i will try to change after i got.

 

[KrisBlueNZ]

I have only this multimeter so i can't measure.

There are lots of ways to check a fuse without using a multimeter. In this case you can check it by (a) connecting your temperature probe, selecting the temperature range, and bridging the fuse with a pair of pliers - if the temperature indication comes right, you know the fuse is open, or (b) checking that the multimeter can measure current on the µA/mA range.