Need help with a DMM

Dido

Aug 24, 2004
72
Joined
Aug 24, 2004
Messages
72
I have a problem with my DMM. I OverVoltaged it It can mesure up to 1kV I measured maybe 5kV with it. Now It displays on the 3.5 LCD Display just the number 1 whatever I try to measure Ohms Amps Capacitance frequency etc... I opened the multimeter and I saw nothing interesting there five or six Op-Amps a main chip made on the PCB board which I most probably think that is the ICL7106 - this is an analog to digital converter, lcd display driver, there are although some analog circuits inside there. I want to ask you Is that IC the problem (I think it is) I`ve attached the schematic see it nothing else I just want someone to advise me should I try to change the IC or throw it away.I think that if I change the IC it will most probably work. Maybe I`ll have to tune it up a little. ???

View attachment 36098

 

ante1

Jan 24, 2004
4,138
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Jan 24, 2004
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4,138
Check the voltages on the 7106, first the supply then the inputs. If you are lucky it

 

steven2

Jan 19, 2004
1,698
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Jan 19, 2004
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1,698
:)if all else fails get another multimeter and remember anything higher than 1000 volts you would need a high voltage resister devider to help and with your multimeter you can measure these high voltages if any voltage you measure exceeds the maximin voltage rateing of your multimeter then you may have problems

 
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