Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

[beetle1303]

I have a 7-year old Panasonic inverter refrigerator model NR-BY602XS that went from working normally to completely not cold air overnight (both freezer and refrigerator compartments...

The service manual instruction on Self Diagnostic Test seems to indicated Compressor faulty or locked. But the compressor seems to be working with humming sound and vibrating at variable speed and noise level..

Everything else seems to be working normally - power cycled a few times has no effect. All the interior lights, and fan are working. I dismantled the interior panel to expose the evaporator and fan (the condenser unit is concealed). The fan runs continuously, but the evaporator does not feel cold at all.

I did a quick visual check on the controller board - nothing looked obviously bad. I check all the capacitors and all tested OK around the capacitance value.

After reading some online postings, one of the test I did was checking the temperature sensor - one attached at the evaporator coil, and the other at the ice-maker compartment. Both sensor read around 1.5kOhm at room temperature (around 26-28c). I dipped one of them into a cup ice-water, and the reading went up quickly, and stabilized at 5.8kOhm, after a minute or so.

I can't find the specs for this particular temperature sensor (see pic), but most the I found online indicate should be around 5kOhm at 25c and 16kOhm at 0c.

Could these temperature sensors be faulty and causing the fridge not cold completely?

Any other test to find out way it stopped cooling completely?

[beetle1303]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

Having problem uploading pics - will try again later...

[stj]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

if the compressor works and you dont have a fluid leak - it works.

so i'd say the compressor is stuck or the starting relay/cap is bad and the noise your hearing is the compressor trying to get enough momentum to start.

[beetle1303]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

I am assuming you are referring to the start relay at the control board since this is a inverter compressor. How do I check if it is good or bad?

Also, what about the temperature sensor - do they look normal based on DMM test outcome?

** is there a problem with uploading pics? I still get error when uploading...

[R_J]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

This inverter fridge uses a 3 phase compressor motor, check the connections on the inverter board, Try checking the a/c voltage going to the motor, also check the resistance of the 3 motor windings. Also check the overload protector and reactor.

If you suspect the compressor is locked, sometimes you can tap it with a rubber hammer and see if it will start.

If a sensor was bad, it would tell the control board to either never start the compressor, or it would run all the time freezing everything

To upload pictures, click on Go Advanced, then click on the paperclip (next to the smile face) then upload your pictures.

[beetle1303]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

After listening more carefully to the compressor, I think the humming and vibration is quite low and consistence. I can also hear gurgling noises around the evaporator.

After power up and running for a few minutes, I gave the compressor a few hard knocks with a hammer (over a thick magazine). Nothing happens...

The resistance between the 3 compressor pins all read 9.4ohm.

I am not certain about how to measure the voltage going to the compressor. This is what I think:
1. set DMM to AC
2. poke to black probe into pin 3 (blue)
3. poke the red probe into pin7 (white), pin9 (black), pin11 (gray) respectively

Is this correct?

How do I check the overload protector and reactor?

[beetle1303]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

This is a 240V DC compressor? So should I be checking for DC voltages into the 3 pins?

*for some reasons, I frequently get this error when uploading pics:

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 27000001 bytes) in /home/badcaps/public_html/forum/includes/class_image.php on line 2390

Any idea why this is happening?

[stj]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

sounds like your picture is too large

[beetle1303]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

Ahh!! Thank you thank you

Please see the pic of compressor and temperature sensor.

What type of sensor is this, and what would be the temperature at 25c and 0c?

[R_J]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

The compressor is a variable speed by the looks of it, 240v 57~240hz, the control board is basically a variable frequency drive that runs the motor. You should be able to measure the AC voltage VtoU, VtoW, WtoU, should show aboout 240vac

I am guessing that is the defrost sensor?

[beetle1303]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

Yes - the sensor is a defrost sensor. There is another similar on at the ice maker in freezer compartment. When probed at the cable connector, it measure 1.58k ohm, but when power up and probed at the connector pluck back onto the controller board, it measured 0 ohm, ~2VDC..

Shorted?

On the compressor:
I measured the voltages among the 3 pins - they all read ~160VAC. I am curious about DC - and they all read ~180VDC..

I also measured:
Incoming ~240VAC
Reactor 0 ohm
Over-voltage Protector 0 ohm

I connect a lead wire onto the blue and brown connector of the over-voltage protector, it measured 0 VAC/DC...

*all these while, the compressor is still humming and vibrating, but not hot..

Does it sounds like the compressor is mechanically jammed?

[budm]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

"When probed at the cable connector, it measure 1.58k ohm, but when power up and probed at the connector pluck back onto the controller board, it measured 0 ohm, ~2VDC.. "
You do not perform resistance reading when the circuit is powered, you can easily damage your meter. Please read your meter user manual.

[RJARRRPCGP]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

*for some reasons, I frequently get this error when uploading pics:

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 27000001 bytes) in /home/badcaps/public_html/forum/includes/class_image.php on line 2390

Any idea why this is happening?

That's strange, I've had no problems uploading images during the last time I uploaded photos.

I think it's because they are being shrunk for me...

[beetle1303]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

"When probed at the cable connector, it measure 1.58k ohm, but when power up and probed at the connector pluck back onto the controller board, it measured 0 ohm, ~2VDC.. "
You do not perform resistance reading when the circuit is powered, you can easily damage your meter. Please read your meter user manual.

Noted, and thank you. I am learning as I do not have prior training or experience.

[beetle1303]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

That's strange, I've had no problems uploading images during the last time I uploaded photos.

I think it's because they are being shrunk for me...

I believe this is due to the file size too big. My phone pics are 3-4mb and I had to do a simple screen capture to reduce the size, and it works.

[beetle1303]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

Based on this sensor specs, I believe the 2 sensors I tested measuring at 1.58kOhm at ~26-28c, and 5.8kOhm at 0c should be working normally.

On the overload protector - how do I determine if it tripped open due to over-voltage or not?

[RJARRRPCGP]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

I believe this is due to the file size too big. My phone pics are 3-4mb and I had to do a simple screen capture to reduce the size, and it works.

For me, it looks like I can upload the original photos from my phone and they end up getting downsized automatically instead of an error. Why is that? Are mine still smaller, even when quality very high?

[stj]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

i suspect the motor may have a bad phase or drive line,
if it hums then the electronics are trying to run it.
we need board pics.

[Per Hansson]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

*for some reasons, I frequently get this error when uploading pics:

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 27000001 bytes) in /home/badcaps/public_html/forum/includes/class_image.php on line 2390

Any idea why this is happening?

Could you put this original picture somewhere so I can make some tests with it?
(Obviously you would need to use some other website if you get the error above here...)

[RJARRRPCGP]

Re: Panasonic Inverter Refrigerator model NR-BY602XS - suddenly not cold overnight

Could you put this original picture somewhere so I can make some tests with it?
(Obviously you would need to use some other website if you get the error above here...)

Was it really bigger than 128 MiB?! WTF!

It looked like I calculated the bytes-to-megabytes correctly.

Normally, this would look like a server-end problem.