Wine and Beverage Cooler Control Board Repair Attempt

[sam_sam_sam]

Let clarify that where to charge with liquid or gas if you have gauges on both sides of the system you should always charge liquid on the high side and gas on the low side when you have the running the compressor

There is only one reason why you might not want to charge with liquid on either side of the system and that is if a rotor type of compressor because it does not have much oil in the system and you might push all of the oil out of the compressor but this only true on the pancake style compressors not so much on other types of compressors as far as I know

I personally do not like to use any type of sealant in a sealed system because in some cases it can severely contaminate the whole system and if you do not experience cleaning out a contaminant system it is not fun at all and it is very time consuming endeavor I do not even like to use leak detector dye either for the same reason I would only do it as a last resort type measure

Now supposedly there is evaporator coil epoxy made for aluminum coil I personally have not used but I have heard of it being used I could not tell you how well it works and my guess is that you would need to know exactly where it is leaking Freon for the repair to be successful or not

One note I am not sure if you have a very slow leak in the evaporator coil weather or not the sealant would work because some of the sealants are heat activated unless some other type of activation method is used and what is the risk of it clogging up the filter dryer or cap tub or whatever method of metering device might have been used

Most refrigerant is a blend now days and when it goes to a gas it does not necessarily keep the blend in correct per portion that is the reason why when you have a gas leak it is recommended that you dump the remaining refrigerant and vacuum the system and start all over again ( one note R22 was not a blend pre-say so you did not worry about dumping the charge unless you had very low amount of gas in the system ) also R134A is also a blend as well so I do not understand the reasoning behind this recommendation for doing it that way

[KYBOSH]

Let us know what happens when you recharge make sure that you dump the remaining charge then put a vacuum pump on for at least an hour then recharge the system for best results make sure that you look at the temperature pressure chart for what your low side should be you want the suction line to feel cool but not really cold because if it gets to that point you might have it over charged you can find this information on the internet

You want a evaporator temperature to be around 38*F for the temperature pressure chart for the correct amount of charge to be put in just remember that when the cooler gets to 38*F that you have a minimum of what ever pressure is needed for 38*F

Now if you are lucky enough that the data plate happens to have how many ounces of Freon it is supposed to have if you are using standard length of charging hoses then you would add 3 to 5 ounces more than what the data plate shows because when you take the hose or hoses off you will loose this amount of Freon

Thanks Sam!
I always vacuum out the lines before recharging and when charging I always have the can on a scale and fill to specifications. In this case it'll be 1.4oz. Even though I have a gauge I have not had much experience using the gauges to know when the system is full or not. But because I always evacuate and refill its never really been an issue. One thing that Im noticing about this R600A is they say you should fill with liquid rather than with the gas (inverting the bottle if needed). This is the opposite of what I am used to with R134a where they warn NOT to fill with the liquid.

Im also going to use a little bit of RectorSeal Ac Leak Freeze Sealant as I dont want to do this a second time. I have had great success with this product on another beverage fridge I restored about a year ago.

[sam_sam_sam]

Let us know what happens when you recharge make sure that you dump the remaining charge then put a vacuum pump on for at least an hour then recharge the system for best results make sure that you look at the temperature pressure chart for what your low side should be you want the suction line to feel cool but not really cold because if it gets to that point you might have it over charged you can find this information on the internet

You want a evaporator temperature to be around 38*F for the temperature pressure chart for the correct amount of charge to be put in just remember that when the cooler gets to 38*F that you have a minimum of what ever pressure is needed for 38*F

Now if you are lucky enough that the data plate happens to have how many ounces of Freon it is supposed to have if you are using standard length of charging hoses then you would add 3 to 5 ounces more than what the data plate shows because when you take the hose or hoses off you will loose this amount of Freon

[KYBOSH]

Wanted to update this thread with some good news. Finally got the replacement power board in. I waited almost 3 months for it to get back in stock and it was finally delivered today. Unit fired right up!



Thanks to everyone who help me comb thru that board. It was a good learning experience!
Here's a side by side of the old board and the new. They are basically identical with no changes in design or components. I didn't bother testing or probing anything as we pretty much figured out that it was the main processor chip that was dead.



Thw unit is not cooling but everything seems to be operational so i will recharge it with refrigerant (R600a) and it should be good then.

[KYBOSH]

If it has a mechanic compressor then after you turn it on the discharge line should strat to get warm to the touch after a minute or two of running if this the case then you should start to see the suction line start to get cooler to the touch after a few minutes after that if this is the case turn off the power especially if you do not have any of the fans hooked up to the cooler now it might not have a condenser fan but it might have a evaporator fan if not then it might take a little bit longer for the suction line to compressor to get cooler than it was before you put power to unit

It has both a condenser fan and 2 evaporator fans (one for each chamber). I was thinking of connecting the condenser fan to 12v external power while I ran the experiment. Since I have access to all the fan I may run them all on external power while the compressor is working. Either way, as you guys said, it won't take too long to see if it's working or not. I'll remote back shortly.

[sam_sam_sam]

If it has a mechanic compressor then after you turn it on the discharge line should strat to get warm to the touch after a minute or two of running if this the case then you should start to see the suction line start to get cooler to the touch after a few minutes after that if this is the case turn off the power especially if you do not have any of the fans hooked up to the cooler now it might not have a condenser fan but it might have a evaporator fan if not then it might take a little bit longer for the suction line to compressor to get cooler than it was before you put power to unit

[R_J]

There should be no problem running the compressor on its own, you should be able to tell within 5~10 minutes if it is working, the evaporator coil should start to get cold and the condenser coil should start to get warm indicating it is pulling heat from the fridge
Seems like it would be worth getting the board based on the price they charge for the cooler

[KYBOSH]

Did you try contacting the manufacturer (Edgestar?) about their pos cooler and see if they would send you a controller cheap?

Got a reply from their Warranty Dept and the replacement board is only $60US. Very surprised its so affordable! This might be the way to go assuming the rest of the appliance is functioning properly (compressor, etc).

Would it be a good idea to wire the compressor to the mains directly and let it run for a while to see if the unit gets cold? It would run constantly until i cut the power or it overheats as it does not have a controller or thermostat to govern its operation.

[KYBOSH]

Something like this should work for your application

https://www.ebay.com/itm/26082383158...Bk9SR9qK3NmzZA

Thanks for this. Ive seen these before. I'll look and see if they have a fancier unit which does auto defrosting and the likes. I'd also need something to couple it with for the DC accessories (fans for instance).

[sam_sam_sam]

@sam_sam_sam waiting to hear back from you.

Something like this should work for your application

https://www.ebay.com/itm/26082383158...Bk9SR9qK3NmzZA

[KYBOSH]

Did you try contacting the manufacturer (Edgestar?) about their pos cooler and see if they would send you a controller cheap?

Thanks R_J. Just submitted a request to their Customer Service page. Will report back with their response.

[R_J]

Did you try contacting the manufacturer (Edgestar?) about their pos cooler and see if they would send you a controller cheap?

[KYBOSH]

@sam_sam_sam waiting to hear back from you.

[KYBOSH]

Or you could just by pass the controller and put your on temperature controller and be done with it if the cooling modules still work yeah this is going to be some work but not impossible to do I done this few times in the past for controller that stop working I just put my on available controllers that still will do the job

If you need a website link to temperature controllers just let me know and I will post a few different ones that could be used to make it work

Wow....it never occured to me to do something like this.
i would love to try this on. The webkink would be greatly appreciated!

[sam_sam_sam]

Or you could just by pass the controller and put your on temperature controller and be done with it if the cooling modules still work yeah this is going to be some work but not impossible to do I done this few times in the past for controller that stop working I just put my on available controllers that still will do the job

If you need a website link to temperature controllers just let me know and I will post a few different ones that could be used to make it work

[KYBOSH]

As much as it pains me to throw in the towel I have to admit that anything having to do with the microprocessor, which all indications points to being the problem, is way out of my league. It was a good learning experience though. Thanks to every one of you guys who chipped in with pointers and ideas. Big thanks to you R_J. You went above and beyond the call of duty. Only regret is I lacked the experience to score a win.

[R_J]

Thanks for pointing out my mislabelled Pinout!
I will go and check on some of those transistors to ensure they are working.

What's the deal with resetting the MC?
Is this something that I can do or try?
PowerON reset sounds like the most user friendly one.
Is it as easy as holding down the power button or something?

There is nothing to reset, some microprocessors use an external reset circuit this one does not. it has an internal reset that does that when power is applied, the reset is needed so the program will start executing from the beginning and not somewhere part way into the program.
On a microprocessor with an external reset circuit, if that circuit failed and the reset pin was held in reset position (either high or low) the program would not run and the micro could appear dead

[KYBOSH]

There is a jumper wire from U1 ground to just above R11, a trace runs under R11 and connects to the left side of R12. The lower side of R41 connects to a +5v ltrace that also runs under R12 and R11 and finds its way up to U1 +5v
Your X1 pinout is wrong, should be L5, L6, +12v
Q6 is the fan control transistor, it connects the fan negative to ground, Q6 base is controlled by the micro via R11

Thanks for pointing out my mislabelled Pinout!
I will go and check on some of those transistors to ensure they are working.

What's the deal with resetting the MC?
Is this something that I can do or try?
PowerON reset sounds like the most user friendly one.
Is it as easy as holding down the power button or something?

[R_J]

There is a jumper wire from U1 ground to just above R11, a trace runs under R11 and connects to the left side of R12. The lower side of R41 connects to a +5v ltrace that also runs under R12 and R11 and finds its way up to U1 +5v
Your X1 pinout is wrong, should be L5, L6, +12v
Q6 is the fan control transistor, it connects the fan negative to ground, Q6 base is controlled by the micro via R11

[KYBOSH]

Not sure what EC14 is for exactly, but it seems to be for some time delay. its negative is connected to ground and its positive connects to R41 (5kΩ) and D15 cathode and the other end of R41 connects to +5 volts, D15 anode goes to pin 20 of IC1
So 5 volts charges EC14 via a 2meg resistor and the anode side of the diode connects to the 5v via R42 (30kΩ)

Correct me if I'm wrong but isn't the negative of EC14 connected to emitter of Q6 after going through the 0-ohm resistor?
The collector of Q6 seems to be connected the F1 lead as well as the neg of EC12.