Re: Oster wine celler cooler Mod OW0912H6H fault

Ok, very basic repair guide...

"If the voltage is within AC100-120V, then test the output voltage, if the voltage is not within DC12-13V, then it must be the problem of the PCB, change the PCB."


Just get a new power supply! Or like you, go to flea market and get a
new fridge..

Well, I agree with getting a new power supply rather than just blindly swapping all its parts, that's what I did the first two times.
BUT, it you can find the one or two bad parts, its better...

Re: Oster wine celler cooler Mod OW0912H6H fault

ivtec,
I wouldn't give up yet!
You can check the big dual diode in reverse mode, put the red probe in the middle, readings should be high.. if so it is good, reattach it.
What are the symtoms? Nothing works? Fans, LEDs work? Disconnect the big wires to the Peltier device and see if the fans work.
What were the measurements on the two small transistors? BTW, the devices on the the other heatsink are transistors, not diodes.. however they would test the same with your meter.

It sounds like you have...

Re: Oster wine celler cooler Mod OW0912H6H fault

Looking at your photo again, I see why you zeroed in on the dual diode...
It isn't even attached to the heatsink!
If that is so, that isn't good, my heatsink gets really hot.
But, your readings look good and it did work for years...

Can you identify where the smell came from?

Use your meter diode function to test the small transistors, they should measure the same.
One of mine was shorted (zero ohms). But it didn't look burned, nothing did.

Gary

Re: Oster wine celler cooler Mod OW0912H6H fault

Your measurements look correct. What about reversing the leads?

BUT, take a look at this thread:
[url]https://www.badcaps.net/forum/showthread.php?t=42346[/url]

It looks like you are working on a very similar wine fridge.
I finally was able to fix mine (actually 3 of mine).

The problem was the VDD 47ufd cap on pin 12 of the tl494 (16pin dip device). It had gone to 33ohms ESR. This caused faulty startup operation which also took out one fo the small TO-92 transistors.

...

Re: Wine Fridge Power Board



THANK YOU! Looks like Rubycon p/n 50YXJ47M6.3X11 then. Rated at 105degC, 7000 Hours. This is the 50V version but has better specs (I think) and is a nickle cheaper than the 25V version, only $0.26 at Digikey.



Yes, it is right next to the heatsink! Could easily be mounted further away, will do that. At least it is UNDER the heatsink as the board is mounted in the fridge, heat rises and probably cools it a little!

BTW, the article that helped solve this repair was this one:
[url]http://ludens.cl/Electron/PS40/PS40.html[/url]...

Re: Wine Fridge Power Board

Thank you!
Share a part number/supplier?
Looking at Digikey, they don't specify ESR for Rubycon without going though a lot of datasheets?
This cap is just a supply filter cap (though it runs at about 6KHz) why is low ESR all that important?
It seems to me that what is needed is not so much a low ESR cap as a cap that stays low ESR! I was thinking more about specified life hours and temp rating??
Maybe there are spikes about 25V so it should be a higher voltage cap?

Lifetime of these supplies seems to be...

Re: Wine Fridge Power Board

Was able to fix my three of these supplies.

ALL had a bad C8 Vdd supply cap. ESR was about 33ohms!

Having a bad Vdd caused two of the supplies to also blow T5 small NPN transistor. I replaced one T5 with a common 2n3904 I had, seems to work fine.
I need to get another C8 for the other supply.

C8 seems to be under the most stress. Is there a really good replacement that could fix the un-reliability of this supply?

Now to go have a glass of wine..!
C5GARY2

Re: Wine Fridge Power Board

Hi,
Its 2017 and I am trying to fix one of these supplies from my Haer wine fridge.
The problem is at startup. Watching the VDD line, it cycles for a little while and then gives up. If I remove the Peliter load, it will power up fine to 12V, the fans and LED works..If I then hook up the Peltier, it keeps working fine. I can adjust the temp and everything.
This is the third one of this supply that has gone bad, I am tired of buying new ones. On one of the other ones, I pulled, tested and replaced all the LV caps.
The worst ESR...