buggy board, bad tech and strange readout... heh heh

[roughshawd]

I would be probably better off just buying a new PBA and put it in the fridge, but I feel so close to fixing it!!!
Everything still looks good, in fact the readout seems to be running better than it did before except that the sensors are not proper, and read out -8 degrees while the Wi-Fi tells me the fridge is ok and in actuallity, it is not cooling down at all !!! and sends an error back that says the freezer is overheating.
The main PBA board is different from the one in the repair manual... I can say and will post some pics... that the GGHI4-PJT C/NOA41-00827B 2016.12.28 Ver.01 B178X197, does not have the same configuration as the one in the book, but, it does seemingly does have the same pinouts. the board, having a part ID QR scan code of 06DA9404399E 100DMBC0311 is all parallel in sensor pinout and all series in Power pinouts --- Where the power pinouts driver heaters, motors and one lamp, and the sensors .
I had it cooling fine, sensors to the readout panel was working, did some repairs and it stopped cooling down.
Defined as something that I did, changed something!!!
better tie me down to the kangaroo and put me on a daily vigil... I think I'm going to be here a while!

I am going to try some things, and I don't need you guys getting upset about it. Its just an old junker smart fridge!

First thing I want to try, is going through my notes and see if I have the wires I fixed in the correct places... working laying down in the floor, and trying to wire a plug in under the front of the fridge with about 2" of space to work in was slightly disturbing!!!
Then I am going to turn off the individual room heaters, so the individual rooms will cool down rahter than defrost... As they may be defrosting all the time, keeping the rooms nice and dry and warm... this is on the assumption that the system might adapt to a failing door sensor, and warm up the fridge, so it doesn't blow up the compressor trying to keep itself cool. then I am going to indivdually disconnect each system, restarting on 15min intervals to allow everything to adapt to its failing system. there is an EEProm on the board in the book, and if i can reset the one on my board, it just might rebuild its index and restart the system.. I think that 20pin port is a diode option setting port.

The board in the book is a ROMANEE-CONTI-PJT C/NOA41 008( )A 2012.04.25 Ver.01 but I can't read the final number.
17 B or 8 something something 7. I would like lines to both these replacements if you got them!!!
GETTING PICS FOR YOU!

 

[roughshawd]

This is a pic of a stamp on the board it says Sensor CheckPoint and its numbered 1 through 13 for the individual sensors on the board. It is next to the 20 pin pinout next to the micom brainiac central processor chip in the middle of the board.
note for dedicated fans...
Arduino on steroids.

 

[kellys_eye]

ISTR we've been over this before (sigh).

The printed references relate to the pins of that port and allow a test set to be connected to examine all the onboard sensors around the fridge. You can measure them individually using a simple volt meter assuming you know what the voltage SHOULD be.

 

[roughshawd]

Is that probe grounded to the board, or the case of the fridge, or just a divergent idiot on the business end of an oscilloscope?

 

[kellys_eye]

As with any (non-differential) signal measurement, the ground is the common ground of the power supply.

 

[roughshawd]

That's not what I learned in my basic electronics class. The actual ground is whatever ground is used on the board to handle the signal...
Like if you have a 5v signal, you have to use a 5v ground or the signal feedsback. Now I know there is a such thing as a feedback circuit, but I don't know anything about those, can you give me a short headsup?

 

[roughshawd]

One other thing, can I test this board out of the fridge using a digital oscilloscope/multi-channels or is it one of those handheld passive sets that cost a grand or two?

 

[kellys_eye]

That's not what I learned in my basic electronics class.

Retake (or maybe just 'take) that class.

 

[kellys_eye]

One other thing, can I test this board out of the fridge using a digital oscilloscope/multi-channels or is it one of those handheld passive sets that cost a grand or two?

Cheaper and easier to use a simple test meter (multimeter).

 

[crutschow]

The actual ground is whatever ground is used on the board to handle the signal...
Like if you have a 5v signal, you have to use a 5v ground or the signal feedsback

The circuit signal ground is usually tied to the power supply ground.

I have no idea what you mean by using the "signal feedsback" (whatever that is) as a reference.

 

[Delta Prime]

or just a divergent idiot on the business end of an oscilloscope?

Hey...I resemble that remark!
do you mean the controlled feedback concerning the amount of energy that must be moved varied on the desired temperature of the cooled space, the ambient conditions, amount of humidity etc, and the level of internal heat generation within the cooled space perhaps in response to an defective actuator for example the door being left open on an refrigerator . In it's simplest form would require an oscillator who's zero crossing would be akin or same thing as ground reference or 0 volts.?

 

[roughshawd]

same ol' same ol' kind of similar in theory... to make a longer story shorter, the 40 dollar manual is all about how it works and not what it does.. so take a look at these neat snap shots of the board to the manual pictures comparison... the manual is missing a 2 pin connection along the egde where I have 6 and themanual has 5 and there is a spare connector in the middle of the board where I don't have any connector and the manual has a well connector...

 

[roughshawd]

Now I remember something about talkback... I asked about why they had radio sets TX and RX on a control board, and they said "talkback. You will see more of this....." this means that the board can't know what its doing without knowing what the sensors are saying, and that is done with talkback. If a cold sensor says "Im not cold", then the board can turn the temperature down if the talkback says "its ok to turn the temperature down because the defroster is not on". so if the defroster is off, the board turns the cooling fan back on, or the compressor on or what ever to make the room cooler.
problem is that the room didn't cool, that means that either the talkback is wrong or the defroster is on, or... in the case of a repair guy who needs money... the sensor is failing.... and well, the people are mad cause the repairguy has to keep coming to fix it, and their food keeps spoiling because the fridge is f***ing up or as the case may be. Could I have in advertently plugged the wrong cable into the wrong pinout OH no... Mr. Bill answer "Yes I could have" a little more study, and a little less demand!

 

[kellys_eye]

I asked about why they had radio sets TX and RX on a control board,

It's to allow an external computer to communicate with the board processor - potentially to reprogram after the board is initially installed or to upgrade it. Very common on processor controlled machinery.

 

[roughshawd]

A second theory is based on the fact that many of these fridges failed... Maybe in assembly, someone in the assembly line plugged it in wrong, and in trying to get it to work, thinking the software was bogus, they adapted the board to function in a compatible mode to recoup their losses... OMG... The plot thickens...

 

[roughshawd]

These are not keyed, and there are 2 two pins and 4 four pins. They effect defrost heating, door heating, H/B heating( whatever that is) Com1 and Com1, the ice maker it's auger, and ice release heater, the water delivery system and 2 sub heaters. Yes I would say that could be the fix I am looking for.

 

[roughshawd]

The board has some pinouts on one of the 11 pin connectors that I don't know. They say C-FG, F-FG, that probably means Freezer-FG, R-FG,(R for refridgerator)and CV-FG for the flex/cold room/laugering room, and ICE-FG.. But what does FG stand for?

 

[roughshawd]

Smart assembly too....
They fixed it with multiple connector blocks.. two blocks in a single wiring plug. Can't miss.. wrong error, bad morda!

 

[kellys_eye]

many of these fridges failed... Maybe in assembly,

No. QC wouldn't allow them out the factory. Didn't the thing work when you got it? Or whenever the original owner got it? Any failure during initial ownership would have been fixed under warranty so the thing HAS worked and probably worked well for years.

The biggest problem is 'you' since, if you'd asked for help before you 'opened the can' you might not be so tangled up as you currently are. The worst thing any engineer faces is a customer who's 'had a go' themselves and, worse still, can't recall or understand what it was they did. Engineers facing this situation either walk away or charge a huge fee and I don't blame them.