help with wine cooler-something buzzing

[CapLeaker]

Re: help with wine cooler-something buzzing

Maybe there is nothing wrong with the psu and just something else drawing too much current from it? So if you plug in the psu into mains by itself with nothing connected, that transistor that got hot should stay cool.

[R_J]

Re: help with wine cooler-something buzzing

If the power supply is working at all, the ic will be good

[buchman]

Re: help with wine cooler-something buzzing

How can I test the ic AZ494AP-E1 with a DMM to be sure that it's the bad part?

[buchman]

Re: help with wine cooler-something buzzing

I was just going by the bottom of the board and it did'nt look like the caps like C4 and the 2 between the ic and heatsink had been out

Then it probably showed a good reading while in circuit.

[R_J]

Re: help with wine cooler-something buzzing

I was just going by the bottom of the board and it did'nt look like the caps like C4 and the 2 between the ic and heatsink had been out

[buchman]

Re: help with wine cooler-something buzzing

It's a good chance those small caps. around the transformer or more likely the ic are bad. They can look ok but be bad.
were the parts you replaced bad?

I have tested all the capacitors out of circuit with an esr 70+ meter, they are all fine.
All the parts circled in red that I mentioned before were bad.

[R_J]

Re: help with wine cooler-something buzzing

It's a good chance those small caps. around the transformer or more likely the ic are bad. They can look ok but be bad.
were the parts you replaced bad?

[buchman]

Re: help with wine cooler-something buzzing

Does the fridge work? Sounds like there is a high load on that transistor. Maybe DL the datasheet of the AZ494 and probe around it? Can we see the bottom side of the board? Can you circle all the parts you have changed so far on the pic?

the fridge work but the display is flickering.
parts that I have changed:
2 big caps, 5 diodes, 2 resistors, 2 transistors and a fuse.

[CapLeaker]

Re: help with wine cooler-something buzzing

Does the fridge work? Sounds like there is a high load on that transistor. Maybe DL the datasheet of the AZ494 and probe around it? Can we see the bottom side of the board? Can you circle all the parts you have changed so far on the pic?

[buchman]

Re: help with wine cooler-something buzzing

One more thing I have noticed that, one of the transistors (13009-2) on the heat sink is getting very hot while the other one (which is the same one) isn't getting hot at all.

Circled in red.

P.S. I have replaced both of them, replaced a few caps, diodes, resistors and still, the transistor is getting hot and I hear buzzing on the transformer.

[buchman]

Re: help with wine cooler-something buzzing

my suspect would be the choke coil next to the heatsink.

Can you mark it please?

[Th3_uN1Qu3]

Re: help with wine cooler-something buzzing

Take out the transformers and coils, dip them in lacquer/varnish for a few hours, take them out and allow to dry for 24 hours, solder them back in. Your buzzing problem should be solved.

[buchman]

Re: help with wine cooler-something buzzing

replace ALL lytics.
i have a fridge with that exact board and the caps are all shot.

Did that already. I have an ESR meter.

[CapLeaker]

Re: help with wine cooler-something buzzing

caps can look A1 from the outside, but still have high ESR. I recapped a fridge board a half a year ago, because of strange behavior...

[kc8adu]

Re: help with wine cooler-something buzzing

replace ALL lytics.
i have a fridge with that exact board and the caps are all shot.

[stj]

Re: help with wine cooler-something buzzing

my suspect would be the choke coil next to the heatsink.

[buchman]

Hi everyone,

I have a wine cooler that I suspect the transformer is buzzing.
How can I test the transformer to be sure that it's the culprit (I have tested it for resistence and it was fine, no shorts).
Is there another test?
photos attached.
Thanks.