Need advice on testing this Circuit Board

Thread Starter

Lumenosity

Joined Mar 1, 2017
461
Stopped working suddenly.

It will power up and everything seems to work, but when I push the start button to begin a capacity test it display "ERR-04", which means "Circuit Error"
So wouldn't that alone tell me certain things are working and maybe narrow down the possibilities?

Can someone just look at this board and give me an idea of what I should check?
Are all those little squares SMD resistors?

It has the following major components on it....

IRFP150N --- Power MosFet - Tested Good
STPS3045CT --- Dual center tap Schottky rectifier
STM8S00 --- 8-bit microcontroller
Ti 272C --- Operational Amplifier
12.000 --- Crystal
78L05 --- 5V Positive Regulator
151 --- Power Inductor
TL431A --- Transistor - Tested good

A few electrolytic capacitors, a bunch of SMD resistors and a few other components but the main ones are listed above.

I'm not sure where to begin with this board because there are so many SMD components.
Can someone Please give me a hand?

Thanks if you can (or will) !

Tester_1.jpg

Tester_2.jpg

Tester_3.jpg

Oh...and there is a sub board that has the digital display and a few LEDs. It has a pin connector and plugs into the main board.

Tester_4.jpg
 
Last edited:

AlbertHall

Joined Jun 4, 2014
8,860
Inspect carefully with a magnifier both sides of the board.
Check the MOSFET and dual diode.
Check whether you get 5V out of the 78L05.
You probably can't get much further without a schematic.
 

Externet

Joined Nov 29, 2005
1,431
Appears to be a voltage/current/Ampereshour/Wattshour meter. Make sure if needs or not to be connected to a supply and load in order to not display 'error'
 

frankr21

Joined Dec 16, 2016
9
That confirm that your mosfet is shorted. It shouldn't let the current flow if there is no voltage on the Gate.
Take a multimeter and mesure resistance between Drain and Source. Normaly it wile not be 0R.
 

Thread Starter

Lumenosity

Joined Mar 1, 2017
461
That confirm that your mosfet is shorted. It shouldn't let the current flow if there is no voltage on the Gate.
Take a multimeter and mesure resistance between Drain and Source. Normaly it wile not be 0R.
Frank, As I understand it, the voltage does not have to be present at the Gate all the time. The circuit inside is turned ON or OFF by applying positive voltage or ground to the Gate....then remains that way until that voltage is drained or shorted off or re-applied..
 

Lyonspride

Joined Jan 6, 2014
137
I have one of those, I seem to remember it can go crazy if the fan isn't working/connected.

Also it has two different modes and it will throw up an error in the wrong mode. The only reference to this I could find was a Youtube video.
 
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