BGAmodz
Member
Hi everyone .
So some days ago i broke one clamp meter due to a high voltage measurement that my device could not handle .
Now after getting a new one , the responsible of the products warranty sold me 4 clamp meters with a nice price , those ones are similar to the other but they are bigger in size and handle very high current ( 2500 A ) , but they are not working .
So i just decided to try my luck and see if i can get at least 2 of them fixed up and sell them to buy an ESR meter , i have 4 clamps ; 3 of them boot but some functions don't work .
1 measures everything but AC voltage ( iso tech )
2 cant measure anything at all except the buzzer
- the last one don't start at all .
After analyzing the one with AC voltage dysfunction , i checked all the caps , transistors , resistors , diodes / zener diodes , and they all seem working fine , no shorts or anything abnormal .
Now things get serious in checking 6 ICs that i suspect at least one of them is responsible for the AC voltage measurement problem .
Here is a list :
NJM022B : dual low power operational amplifier
TS27L2C : Precision very low power cmos dual amplifiers
OP07 : Ultralow offset voltage operational amplifier
AD736 : Low power , true RMS to DC converter
AIC1578 : High efficiency step down DC/DC converter
HEF4066B : quadruple bilateral switches
This one is the main core processor it is labeled NJU 9210 : 3.3/4 digit sigle chip digital multimeter LSI , and am suspecting is the one responsible for the Clamp problem .
A picture of the actual clamps model i got and i hope i get some opinions from you guys .
Cheers
**broken link removed****broken link removed**
So some days ago i broke one clamp meter due to a high voltage measurement that my device could not handle .
Now after getting a new one , the responsible of the products warranty sold me 4 clamp meters with a nice price , those ones are similar to the other but they are bigger in size and handle very high current ( 2500 A ) , but they are not working .
So i just decided to try my luck and see if i can get at least 2 of them fixed up and sell them to buy an ESR meter , i have 4 clamps ; 3 of them boot but some functions don't work .
1 measures everything but AC voltage ( iso tech )
2 cant measure anything at all except the buzzer
- the last one don't start at all .
After analyzing the one with AC voltage dysfunction , i checked all the caps , transistors , resistors , diodes / zener diodes , and they all seem working fine , no shorts or anything abnormal .
Now things get serious in checking 6 ICs that i suspect at least one of them is responsible for the AC voltage measurement problem .
Here is a list :
NJM022B : dual low power operational amplifier
TS27L2C : Precision very low power cmos dual amplifiers
OP07 : Ultralow offset voltage operational amplifier
AD736 : Low power , true RMS to DC converter
AIC1578 : High efficiency step down DC/DC converter
HEF4066B : quadruple bilateral switches
This one is the main core processor it is labeled NJU 9210 : 3.3/4 digit sigle chip digital multimeter LSI , and am suspecting is the one responsible for the Clamp problem .
A picture of the actual clamps model i got and i hope i get some opinions from you guys .
Cheers
**broken link removed****broken link removed**
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