Samsung rs53k4400sa dead

[electrofix]

thats the one
look at the markings on it and see if there is a number

Dave

[electrofix]

are those marking on the chip itself or on the board ?

Dave

[Mrplumber]

Ah right. The numbers I stated were marked on the board.
on the transistor it has
k mbrf20
u 150cta
some symbol then 525

[electrofix]

ok was worth a try
maybe faulty but you would have to know how to check a diode to find out

thought it may have been a power regulator but its a Shottky diode pair in a case used for rectifying the ac output of the switch mode power supply. they can go short circuit and cause these sort of faults

Dave

[Mrplumber]

Ah your correct. I looked up transistor and thought it was it as looked similar. But googled it and your correct. It has the diode sign.
multimeter does have diode setting but would this be irrelevant now.
the transistor thing sounded right as maybe it wasn’t putting the correct voltage out.
could a diode still be suspect?

[electrofix]

yes they go short circuit

had one last week on a tumble dryer

Dave

[Mrplumber]

Sweet mate thanks. Once I fit the new pcb I will learn and fix the old one and show what it was. Your help is appreciated.

[Mrplumber]

Pcb arrived. It’s all up and running.
further learning of the old pcb I found a faulty diode was the cause. On the board it’s marked ds2 and sits next to the heat sink.
just in case it helps anyone

[Gadjet87]

Same thing happened to me. Can someone guide me on how to test whether the diode is working or not? Thank you

[electrofix]

a diode is a one way device
will be lots of videos on utube how to test
but
set multimeter on diode setting
put meter leads on diode look ant the reading then reverse leads and they should differ greatly

if you get the same reading both ways it could be faulty. to be 100{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} sure unsolder from board and test again

Dave

[Author]

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