Samsung SCX5110/5112 no power ( Xerox F12)

[axyun]

F12 was working . Replaced fuser, transfer roller and drum unit. When I turned power on no power. No LEDs indicator light or fans. Nothing. 2 fuses on PSB good. Does machine have power supply issues? Any help is appreciated. Frank/ActionPhotocopy

[Doedee316]

It is similar to 5312. they do have power source PCB problems. JC96-02310B

[axyun]

Thanks Doedee316 for the confirmation and the part number. Frank

[axyun]

Got power supply board today and changed it and allis okay. Thanks again. Frank

[patrick076]

Hello

I have a question why we face this power supply problem

Is it because of the power supply irregularities caused by noise or the power supply cirrcuits just get heat up ?

[tseto]

take a look at the electrolytic capacitors. if the top of the can bulges, it is bad. if so ,replace them and the psw should be ok. I fixed a lot of them.

[axyun]

In answer to why this happens on these power supply boards. My customer never turned machine off at end of day. So it was on all the time. When I changed fuser unit naturally the machine had to be turned off. When I turned it back on ...no power. I guess with some machines it is more risky to leave them on all the time and when they are turned off one day they may not come back on.
Technically I could not say why though it appears the capacitor(s) blow.Frank

[tseto]

Over time all electrolytic capacitor in switching power supplies will develope problem , more so if they are of low quality. you will see that a lot in satellite receivers and situations were the is a lots of heat. BTW it is best to replace them with ones of higher voltage rating for longer life. they cost less than a dollar each.