how to test transformer ee19

Thread Starter

dashhossein

Joined Jul 30, 2020
32
hello every one
for practical learning i have a damaged samsung refrigerator board
i guess the problem refer to transformer
the model of transformer is EE19-220-12-A
it's have 5 pin in one side and 4 in another side
how i should test that transformer ?
should i cut it from board then start testing ?
some one pls help me ...
 

LesJones

Joined Jan 8, 2017
2,729
You have not provided much information. What has led you to believe that the transformer is the cause of the fault and what is the nature of the fault ? Is the transformer working at mains frequency or some higher frequency ?

Les.
 

debe

Joined Sep 21, 2010
1,200
Not mutch information, but it sounds like a switch mode type of powersupply. Unless you physicaly damaged the transformer, then its probably ok.
 

Thread Starter

dashhossein

Joined Jul 30, 2020
32
You have not provided much information. What has led you to believe that the transformer is the cause of the fault and what is the nature of the fault ? Is the transformer working at mains frequency or some higher frequency ?

Les.
theres some burning sign in next to the transformer

i dont know exactly that what pins connected to the ac 220 V
 

Attachments

Thread Starter

dashhossein

Joined Jul 30, 2020
32
hello every one
for practical learning i have a damaged samsung refrigerator board
i guess the problem refer to transformer
the model of transformer is EE19-220-12-A
it's have 5 pin in one side and 4 in another side
how i should test that transformer ?
should i cut it from board then start testing ?
some one pls help me ...
thers some burning sing next to the transformer ...

what i dont know is that i should connect what pin to ac 220V
image_2020_10_12-14_49_19_492_F3t.jpg
 

Marley

Joined Apr 4, 2016
370
This transformer does not connect to AC220V.
This is a high-frequency transformer. Very difficult to test. And probably unlikely to be faulty.
Chances are that the IC U9 is at fault but could be many other things.
Also there is a fuse on the board. Under the black cover next to the white connector. Have you checked that?
Most faults will cause the fuse to break.
If not blown, check the voltage between the wires marked GND and +5V.
Be very careful, there are high voltages on the board.
 

Thread Starter

dashhossein

Joined Jul 30, 2020
32
This transformer does not connect to AC220V.
This is a high-frequency transformer. Very difficult to test. And probably unlikely to be faulty.
Chances are that the IC U9 is at fault but could be many other things.
Also there is a fuse on the board. Under the black cover next to the white connector. Have you checked that?
Most faults will cause the fuse to break.
If not blown, check the voltage between the wires marked GND and +5V.
Be very careful, there are high voltages on the board.
the fuse is ok!
one of my friend change the damaged capasitor 22uf 450 V with 22uf 400 V
will that effect on the application of board ?
 

Dodgydave

Joined Jun 22, 2012
9,688
That's a switchmode PSU, the 8 pin chip will probably be a Viper chip, what is the number on it?

Is there any voltage on the output or chip pins?
 

LesJones

Joined Jan 8, 2017
2,729
I don't think this is a suitable project to try to repair until you understand how switch mode power supplies work and the safety measures you need to take working on the primary side. This is a VERY simplified explanation of how SMPS work. The mains input is first rectified to give a DC supply of about 300 volts. This is then converted to a high frequency (Tens or hundreds of Khz.) square wave with a variable duty cycle by U9. This drives the primary of the transformer and the secondary is rectified. This voltage is compared with a reference voltage to generate a feedback signal which is fed back to the primary side via an opto coupler (To provide isolation.) to control the duty cycle of the high frequency waveform.

Les.
 
Top