Need assistance from a Guru please. Identification process stalled....Icemaker board

Thread Starter

boydage

Joined Oct 7, 2016
84
Ok. Did all of that except for locate the R1 on the motor driver circuit. Replaced C23 just for kicks but no change. Didnt think it was out just the way it charged with my meter.

Managed to locate the little current limiting power supply kit I assembled ages ago. Hooked up the board to 12vdc limited to 1A through C23. Heard a little click. Left it there for a while whilst I ran my finger over all the components and actually didn't find anything getting warm. Not even the motor driver although it had no load on it.

I couldn't help myself and installed it into the fridge with an extension for the accessory 12vdc reconnected. Powered up the fridge. With much glee and much delight watched as the broken waterline (must have been caught on something) sprayed a little water on the floor instead of up to the icemaker. The main front panel lights up. All functions are satis.

Just not sure what to do next. Although I am well happy to install a separate 12v PSU into the fridge to run this board, I have removed it. Do you think I should leave it on the bench powered up for a while just to be sure there isnt something that will go bang? Maybe run a infarred thermometer over it?

Not having done this before am just being cautious. Should I break the connection to the onboard PSU like mentioned before or just leave it like that. Would prefer to do the minimum.

Mr EPB. Do PM me with your address. I want to send you a bag of New Zealand pineapple lumps. Yep definitely.
 

ebp

Joined Feb 8, 2018
2,332
This is good news, since you at least have a method of getting the thing back in service without spending a lot of money.

I'm still left wondering at what might be wrong with the power supply. The problem now is that short of just replacing several components on the chance they might be bad (and this returns to the problem of getting glued-on surface mount components off), trying to diagnose further without an oscilloscope and an isolation transformer is pretty tough. I'm slightly suspicious of the transformer, but there isn't much you can to to test without more equipment. It might be worth replacing C26 and maybe pulling up one end of R47 to verify it is really OK.

I don't see a problem with leaving the board intact. The diode on the output of the switcher will isolate your supply - just check to be sure it isn't warming up, which might indicated it has excessive reverse leakage and could be the root of the problem, but I greatly doubt that.

Running the board on the bench for a few hours wouldn't hurt, but it sounds like everything in fine.

Thanks for the offer of the pineapple, but it would cost you a fortune to ship it and it might not be allowed through Canada customs in any case.

Best wishes!
 

Thread Starter

boydage

Joined Oct 7, 2016
84
Hi. I have a motivation to do the power jump with a decent little cheap PSU I will dig out. This due to the difficulty of changing out any of the components and also the fact I was unable to find a replacement for this board anywhere. I would be gutted if I introduced a fault of my own. Its most certainly a rogue component out if the manufacturer.

I had a fault with a ROV I was in charge of a few years ago. Having gone through all of the "normal" fault finding to find why the machine was on commanded full thrust forward I pulled out the oscilloscope the company supplied. Removed the new packaging, and read the "congratulations on purchasing your new...." But did locate a power supply being naughty. Perhaps I should buy one.

But this board, I will get running and leave the troubleshooting for something that can be replaced if it all goes wrong. Easy enough to take out R47. I will run the board for a couple hours and watch if my power supply lights up with a current limit along with warm bits. That diode, was a component I did visually notice has been warm right from the start. But my meter does make it shut.

Hey just looked. Its $14.75 to send a bag of confectionery to Canada. I think I may have sent my sister a bag of these unique to NZ chocolate bites in White Rock. The internet brings a lot of people together. Online order brides aside, it is rare to put some form of physical means to it. Given the low cost, the fact the post shop is a 10min walk, and its a sealed bag I would be prepared to take that risk. You spent a lot of time on this, and didn't get the result you should have (your not bashing your leg with a baseball bat?!?!? "The Accountant" Ben Affleck). I did. So if you change your mind, please do PM me an address. Although don't want to make it awkward ha
 

Thread Starter

boydage

Joined Oct 7, 2016
84
Well I did it. I connected an alternate PSU. Afterwards I felt kinda dirty. So had a shower and sat in the corner of it for a while.....

But now I get ice by a pushbutton. Instead of digging around the icebox, trying to locate a few lumps that are not all stuck together n stuff.

I feel one again. Many thanks to Mr Epb and all who helped with some very solid advice. Rgds Boydage NZ
 

MisterBill2

Joined Jan 23, 2018
10,495
If you have one of those control boards that you replaced previously you could connect a power supply to it and see if that made it work as well. That would be a no-risk approach, and then you could see what part had failed on that board, and see if replacing the failed part made it function correctly again. Not much cost and zero risk of damaging the working system. Just a suggestion to advance your education.
 

Hymie

Joined Mar 30, 2018
1,013
Well I did it. I connected an alternate PSU. Afterwards I felt kinda dirty. So had a shower and sat in the corner of it for a while.....

But now I get ice by a pushbutton. Instead of digging around the icebox, trying to locate a few lumps that are not all stuck together n stuff.

I feel one again. Many thanks to Mr Epb and all who helped with some very solid advice. Rgds Boydage NZ
Congratulations, besides the satisfaction of fixing it, you have saved yourself some dosh and maybe helped the environment by not consigning the ice-marker to your local landfill.

But hey, credit where credit is due – it was I who suggested powering the secondary circuit using an alternate PSU, rather than trying to fix the PCB switch mode power supply.
 

Thread Starter

boydage

Joined Oct 7, 2016
84
Thanks Hymie this is true. Although I am sure you will respect it did cross my mind when I saw just a couple of volts, but I would have definitely not had the knowledge on whether to cut the tracks nor where to put it in. And I appreciate this a lot. I also appreciate the very long time Mr Epb (or Mrs?) would have spent on this, with patient investigation and advice.

Oh. Re the first replacement board. That was taken away by the tech who replaced it. Very quickly. With a $350 bill and labor additional. I expect it went into the next fridge she repaired. This was a number of years ago prior to my wanting to learn about electronics.

What I have taken away from this, is the TOP device and its layout. That was new to me.

Ok. Monday morning. Time to work. Have a very nice day.
 
Top