Zan ZKH7146J Dead. Is Board Repair Possible?

[laurenceuk]

Hi,

The machine is dead. Power to the board ok but that’s it.

Has anyone been able to identify and repair this apparently common problem with these boards?

Many thanks.
Laurence

[electrofix]

Re: Zan ZKH7146J Dead. Is Board Repair Possible?

look in

simple-pcb-repair-tips-t51155.html

lots of info in here

the only repairable problem is the switch mode power supply chip. check the fusible resistor if its ok then check the voltage output from the power supply by finding the low voltage smoothing capacitors. if the voltage is stable or seem to start to climb then die the board is dead

Dave

[Hollytree_Technical]

Re: Zan ZKH7146J Dead. Is Board Repair Possible?

It will be the resistor and switch mode chip, I have done a couple and both are working fine after replacing those components.

[laurenceuk]

Re: Zan ZKH7146J Dead. Is Board Repair Possible?

Thanks Dave.
__________________
Thanks Hollytree, help in identifying component placement on board would be appreciated.
Thanks again.

Laurence

[electrofix]

Re: Zan ZKH7146J Dead. Is Board Repair Possible?

post picture and will add some arrows

follow live in on board and it will lead to a normally green resistor. expect about 47 ohms or so. that leads on to a rectifier and capacitor to store DC at 350 volts or so.
You will then find a small chip with 7 legs something like LNK304 or I think TNY268
only guessing on numbers but if you google pictures

Dave

[laurenceuk]

Re: Zan ZKH7146J Dead. Is Board Repair Possible?

Thanks Dave,
Will take a look. Should be easy to follow your directions though.

Thanks again

Laurence

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