Koban - Current Clamp Meter - DMM

[neuron]

The factory / reseller ... don't know anything about the device (Schematic, Service manual, etc) and I need to repair this DMM - Clamp Meter.

2TY - Transistor - Q5 (Diode mode ok)

CHX ??? 5 Pins - U3

C31 ??? Burn,

Tested - V, Ohm, Diode, ºC ... don't see any errors

Thanks in advance for all info
Ruy

[stj]

Re: Koban - Current Clamp Meter - DMM

CHX may be XC6116H028MR

[neuron]

Re: Koban - Current Clamp Meter - DMM

CHX may be XC6116H028MR

Thank you,

CHX ... one more letter or number in Koban_1.JPG
I can't find PDF with that reference.

Thank
Ruy

[megaraider]

Re: Koban - Current Clamp Meter - DMM

CHX may be XC6116H028MR

@neuron
stj is most likely right! A simple quick search returns:
Part No.: XC6116H028MR, SmdCode: CHX, Manufacturer: Torex, Package: SOT-25, Pin: 5, Memo: XC6116H028MR, Description: 2.8V Voltage detector, 0.1%, Delay time = 1.6s
The datasheet may not be easy to find but that`s not your major concern, right?
Either way, you can find here the datasheet.

[neuron]

Re: Koban - Current Clamp Meter - DMM

@neuron
stj is most likely right! A simple quick search returns:
Part No.: XC6116H028MR, SmdCode: CHX, Manufacturer: Torex, Package: SOT-25, Pin: 5, Memo: XC6116H028MR, Description: 2.8V Voltage detector, 0.1%, Delay time = 1.6s
The datasheet may not be easy to find but that`s not your major concern, right?
Either way, you can find here the datasheet.

Boa tarde megaraider,

And the procedure to test ?

The last letter ... is necessary?

C31 no info?

I can follow the tracks in the board and
tested 2TY and all resistors around the C31.

C31 in the board ...?

Thank you
Ruy

[stj]

Re: Koban - Current Clamp Meter - DMM

mabe you can find a schematic for a similar meter with the same chip.
Semico CS7721CN
i also found this:
"The CS7721CN is pin for pin compatible with Fortune Semiconductor FS9721"

and a LOT of meter info is here:
https://sigrok.org/

[megaraider]

Re: Koban - Current Clamp Meter - DMM

A long list of chips, schematics, teardown, ... info on Multimeters (DMM):
http://improwis.com/projects/reveng_multimeters/

You can find a long list of devices using the CS7721CN chip along with detailed info.

A very quick look pop-up UT61E (schematics) and Wintex TD2200, quite similar to UT61E. The later as "IC11: some tiny SOT-25 thing..." that might well resemble to the "U3" you found.

[stj]

Re: Koban - Current Clamp Meter - DMM

ut61e has nothing in common with those chips.

[neuron]

Re: Koban - Current Clamp Meter - DMM

mabe you can find a schematic for a similar meter with the same chip.
Semico CS7721CN
i also found this:
"The CS7721CN is pin for pin compatible with Fortune Semiconductor FS9721"

and a LOT of meter info is here:
https://sigrok.org/

Thank you stj, megaraider


2TY 2 - Emitter -> down -> 2 Layer, through hole.
2 - Emitter -> up , Left -> C letter ->
U3 pin 2 VSS -> C31

U3 - pin 1 (down) -> 2 Layer, through hole -> the other C31 pin

Testing U3 (Diode Mode) I get +- 0,56V
Other procedure to test this IC?

Regard,
Ruy

[megaraider]

Re: Koban - Current Clamp Meter - DMM

Thank you stj, megaraider
(...)
Regard,
Ruy

Some thoughts:
U3 is an IC, see the attached image taken from the datasheet.
Follow the 5 pins traces back to the connected points and test if it`s working.

Q5 is most likely a transistor. Remove it from the board and test it.

C31 was a capacitor... value and type remain unknown.
From the previous, and compared to other similar schematics, you should be able to sort it out.

[neuron]

Re: Koban - Current Clamp Meter - DMM

A very quick look pop-up UT61E (schematics) and Wintex TD2200, quite similar to UT61E. The later as "IC11: some tiny SOT-25 thing..." that might well resemble to the "U3" you found.

UT61E is ES51922 !!!
IC11 I can't find ...

DMM use Semico CS7721CN - Semico CS7721CN: UT60C, UT60A

Some thoughts:
U3 is an IC, see the attached image taken from the datasheet.
Follow the 5 pins traces back to the connected points and test if it`s working.

Q5 is most likely a transistor. Remove it from the board and test it.

C31 was a capacitor... value and type remain unknown.
From the previous, and compared to other similar schematics, you should be able to sort it out.

Diode mode?

2TY - I don't need remove from the board.
All my DMM can test Transistors in Boards.

And where I can find that schematics?

In your attach XC61xx.PNG the cap between Vin and ground ... value?

Ruy

[megaraider]

Re: Koban - Current Clamp Meter - DMM

And where I can find that schematics?
In your attach XC61xx.PNG the cap between Vin and ground ... value?
Ruy

See datasheet here.

[neuron]

Re: Koban - Current Clamp Meter - DMM

stj - the only info is MASTECH MS8250B (sigrok.org)

See datasheet here.

It's in japan. and no info about the cap ...

[televizora]

Re: Koban - Current Clamp Meter - DMM

I wonder what happened so the PCB is so burned.

[neuron]

Re: Koban - Current Clamp Meter - DMM

I wonder what happened so the PCB is so burned.

Only C31 Burn

I power up and tested all function
V, Ohm, Hz, Diode, ºC, ... don't see any errors
Zero, Hold, Select.

Ruy

[megaraider]

Re: Koban - Current Clamp Meter - DMM

See datasheet here.

It's in japan. and no info about the cap ...

From the above datasheet, page 11:
4. Noise at the power supply may cause a malfunction of the watchdog operation or the circuit.
In such case, please strength the line between VIN and the GND pin and connect about 0.22μF of a capacitor between the VIN pin and the GND pin.