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Forum Index => Refrigerator & Freezer Repair => Topic started by: jpeters on November 28, 2018, 12:30:52 PM

Title: Lg`s junk linear compressors
Post by: jpeters on November 28, 2018, 12:30:52 PM
Are there any "good " replacements for this junk compressor? Lg not warranting these despite the 10 year compressor warranty. I have a $2800 refrigerator given to me and I was going to experiment on it by trying to retrofit a conventional non linear one. Anyone done this and lived to tell about it?
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 04, 2018, 10:02:34 PM
I was thinking to try the same thing on a used dual evap LG fridge i bought really cheap. The best price I found was $317 plus 15 shipping for another LG compressor.
Only problem is you would need to have your own control system if you went non linear such as using a basic digital PID temp controller to turn a generic compressor off and on.
Since my LG has separate evaporators it would be harder to control but possibly just monitoring the food compartment and letting the freezer run anytime food calls might work ok.
Its a shame these beautiful machines keep breaking down constantly.

Title: Re: Lg`s junk linear compressors
Post by: jpeters on December 05, 2018, 07:04:22 AM
I was thinking I could use a solid state relay. The output from the inverter is an ac signal that can go as high as ~250 volts. There are relays that have a high voltage input.
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 05, 2018, 08:26:45 AM
The problem is the Mainboard knows if the compressor is not working properly and it shuts down the inverter board from sending signals and then sets error codes on the front of fridge.


But you cannot just disconnect the mainboard because that controls the lights, and ice maker, all the fans, etc etc
Title: Re: Lg`s junk linear compressors
Post by: jpeters on December 05, 2018, 08:49:36 AM
Well I guess that`s that then. I did see the microprocessor on the main. Along with the IPM driver module. Without the schematics to the main I can not re-engineer it.
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 05, 2018, 09:43:53 AM
I saw a guy on reddit saying you can substitute a Linear compressor made by Embraco or Samsung if it fits into the area and the feet holes line up. He said they are more reliable than LG compressors.

Here is a link to info about specs on LG compressors I found http://www.frigochem.com/pdf/Refrigerator_Compressor_151207.pdf

What model LG fridge do you have if you get the Service Manual for it they show the schematic of the boards.

Here is the service manual for the model LFX31945 it might help you figure out how the wiring works.

https://drive.google.com/file/d/0B-i5KqMA2RZwYVpiNkZma1NubXc/view?usp=sharing
Title: Re: Lg`s junk linear compressors
Post by: jpeters on December 05, 2018, 01:30:34 PM
Actually is a Kenmore but this model lg appears to be it: lfxc24726. Has the inverter made onto the main board which seems to have everything on it.
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 06, 2018, 11:58:20 AM
Class action lawsuit filed Oct 2018 that mentions your model and mine on last page.


There was already another class action suit that got dismissed last year.


https://www.courthousenews.com/wp-content/uploads/2018/10/LG-CA.pdf
Title: Re: Lg`s junk linear compressors
Post by: jpeters on December 06, 2018, 01:38:07 PM
I knew that there were several class action suits filed but LG failed to respond to them. In my case this is a "KENMORE" sold by Sears. When Sears does their volume buy on things they purchase at lowest cost they can. That means no warranty from manufacturer at all. The warranty comes from Sears. I know this to be true because I used to repair lots of tv sets sold by Sears. Even if the tv had a name brand such as Zenith and it was purchased from sears there was no warranty from Zenith. So in this case it`s pointless to hope to get any help from LG even if the lawsuit is settled.
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 06, 2018, 02:58:42 PM
What compressor does your fridge have?
Mine is the FC75LBNA
I am trying to research a Embraco that will replace it.
I think I am getting close to a match but I have to measure the resistance of the pins on mine to see if the Embraco has same ohm readings or close to it, and then confirm if the height from mounting plate will fit in my fridge.
Looks like plenty of room side to side but the LG compressor on mine has very little clearance on top.

Title: Re: Lg`s junk linear compressors
Post by: jpeters on December 06, 2018, 05:59:20 PM
Mine is flb075lana . You are right about the low profile compressor.
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 06, 2018, 08:11:04 PM
This is the Service Manual for the LFXC24726S

Shows schematic diagrams of mainboard and diagnostics for compressor etc

https://lg.encompass.com/shop/model_research_docs/?file=/ZEN/sm/LFXC24726S_01.pdf
Title: Re: Lg`s junk linear compressors
Post by: jpeters on December 06, 2018, 08:26:03 PM
Actually it does not show the board schematic.....ie capacitors,resistors ic`s etc. I am an electronic tech and maybe could mod that board if I had those details.
Title: Re: Lg`s junk linear compressors
Post by: iyala on December 08, 2018, 06:59:41 PM
guys i hate these refrigerators so much it is not even funny anymore. I work for sears and all i do is practically work on these pieces of crap. even after you replace the compressor sometimes it still doesnt work to find out the system is contaminated from the old compressor and on top of that I have gone back on calls about a year later where the compressor was replaced and then there's an evaporator leak and sometimes its in both evaps. im here checking out to see if there is something im missing when it comes to diagnosing these units when the compressor has already been replaced.  :tickedoff:
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 08, 2018, 08:42:56 PM
guys i hate these refrigerators so much it is not even funny anymore. I work for sears and all i do is practically work on these pieces of crap. even after you replace the compressor sometimes it still doesnt work to find out the system is contaminated from the old compressor and on top of that I have gone back on calls about a year later where the compressor was replaced and then there's an evaporator leak and sometimes its in both evaps. im here checking out to see if there is something im missing when it comes to diagnosing these units when the compressor has already been replaced.  :tickedoff:

Wow really that sucks. I guess the junk from bad compressor get clogged in the capillary tubes and restricts them then high side pressures go up and damage the new compressors. I guess the only way to fix them is to somehow do a flush on the lines before putting in another compressor and use a larger filter drier but only ones I see are the small driers.
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 09, 2018, 09:37:57 PM
Just saw this brand new compressor $100 same one you need maybe they would ship it to you.
https://newjersey.craigslist.org/ele/d/nib-lg-refrigerator-compressor/6733968270.html
Title: Re: Lg`s junk linear compressors
Post by: jpeters on December 10, 2018, 07:08:23 AM
That`s the one. Now I wonder if this one will last longer than a year?
Title: Re: Lg`s junk linear compressors
Post by: Appliance GOD on December 12, 2018, 03:11:37 PM
LG junk....
LG uses 2 different methods to control the compressor speed. One is to vary the voltage, the other is to vary the frequency.
They are 2 different systems, different controllers etc. and components are not interchangeable. LG lables both types "linear compressor".
Look on the compressor label. If it says something like 0-220v 60hz its variable voltage. (Voltage can be 0-180 or anything really)
If it says 200v 0-60khz its variable frequency.
Variable speed compressors will only have continuity between 2 of the 3 pins, the 3rd pin isnt connected to anything.
Variable frequency compressors should read identical resistance between any 2 pins. 
Hope this helps. 
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 12, 2018, 05:21:07 PM
LG junk....
LG uses 2 different methods to control the compressor speed. One is to vary the voltage, the other is to vary the frequency.
They are 2 different systems, different controllers etc. and components are not interchangeable. LG lables both types "linear compressor".
Look on the compressor label. If it says something like 0-220v 60hz its variable voltage. (Voltage can be 0-180 or anything really)
If it says 200v 0-60khz its variable frequency.
Variable speed compressors will only have continuity between 2 of the 3 pins, the 3rd pin isnt connected to anything.
Variable frequency compressors should read identical resistance between any 2 pins. 
Hope this helps. 


Good to know thanks.
Do you think a Embraco compressor can be substituted in a LG?
I found out that the Emnraco model numbers that begin with VEG, VEM, VES are all variable speed. The LG model numbers usually have 75 which means 7.5 cc displacement .
So I was going to try and put a Embraco VEGY8H in my LG because the specs for that are 8cc and it says ohms are 6, and the LG is supposed to be 6-8 ohms so I figured it should work unless there is something internally different other than the motor windings that make it spin such as the magnets or something that is changed between a inverter compressor that works off varying voltage vs varying frequency?
Title: Re: Lg`s junk linear compressors
Post by: Appliance GOD on December 12, 2018, 07:32:00 PM
For the purposes of this discussion, Variable voltage systems and variable frequency systems are completely different. You cant swap any parts between them.
As for the Embraco compressor.... I tend to doubt that it would work. Even if its the same type of system (voltage or frequency) with similar specs it will be somewhat different internally. The LG inverter module wouldnt get the feedback its looking for and probably wouldnt even try to start the compressor. If it did start the motherboard would likely throw a bunch of codes and shut the unit down. 
While it is theoretically possible, decompiling and reverse engineering the control systems would require advanced skills in several disciplines and a lot of time.
If by some miracle you got the Embraco to work, the steel yoder loop will probably rust out n leak in another 6-12 months anyway.
Now theres a fun repair.....
Welcome to the new world economy.

 
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 13, 2018, 12:24:25 AM
Hmm interesting.

My LG has the FC75LBNA compressor that says 0-220v 60Hz so like you say it gets a varying voltage signal into a 6-8 ohm winding.

I read the Service Manual and the IPM chip of the Inverter board gets a feedback signal if the inverter is seeing over current conditions or open circuit no current it flashes the error LED

So my hope is that another compressor with similar ohm reading is connected how would it know its a different compressor as long as the current flow is within the range the IPM logic is looking for it should work (I hope).

Either way its a experiment and the Embraco compressor I am thinking to try is 1/2 the price of the LG and the Embraco (used in Whirlpool and GE and Frigidaire) seem to last longer I don't hear of the complaints about failed compressors as much on those brands.
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 15, 2018, 04:58:16 PM
This interesting video the guy is running a variable speed compressor using a universal VFD Variable Frequency Drive motor controller that is normally used to control 3 phase AC motors in industrial machinery etc.

3 phase motors have 3 wire connections labeled U V W but this guy is only using 2 of the phases since it is not a 3 phase motor.

When I looked at the LG Service manual for my fridge in the section for troubleshooting the Inverter
B5. LED blinks seven times, then repeats (IPM Fault: A & E Inverters)
they show a schematic of the IPMI chip that is on the board and the chip has outputs labeled U V W but the W output is tied back to the chip to terminal Wfb (i assume fb means feedback). So essentially LG is using a chip made for 3 phase motor VFD control and only using 2 phases to run the linear compressors.

The video is here https://www.youtube.com/watch?v=15VOMei7awo
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 23, 2018, 01:28:08 AM
My mother lives in Fla and her neighbor just bought a new LG fridge and the compressor went out already. its still under the 1 yr warranty.
They said the guy replaced it with a smaller compressor and told them that LG finally fixed the compressor problems. They said it is much quieter than the original compressor.
Anyone know if this is true is there a new updated LG compressor that will last?
Title: Re: Lg`s junk linear compressors
Post by: swong on December 23, 2018, 10:26:34 AM
Subscribing to this thread.  We got our Samsung (model LSFXC2496D) over 18 month's ago and there isn't a day that goes by I dread finding out my LG French Door refrigerator won't die a premature death.  I don't wish to jinx myself it also has the unreliable linear compressor.  I do now during the summer months both freezer and refrigerator compartment labors to keep temps 32 degrees fahrenheit and 0 in the freezer.  I just need 10 years out of this before I can get my money out of it.  No choice getting this LG as I got a deal too good to pass up but more importantly it gave up 23 cubic feet of space versus the 10+ year old GE (top freezer) which only provided 14 cub feet combined.  The LG is reliable however we don't have water or the ice cub maker installed which is probably why it is so reliable
Title: Re: Lg`s junk linear compressors
Post by: jpeters on December 23, 2018, 01:24:06 PM
If they really have a good compressor replacement now I may hold out for one.
Title: Re: Lg`s junk linear compressors
Post by: swong on December 23, 2018, 02:20:01 PM
Definitely hold out on this especially if your old refrigerator is still functional.  Samsung, for example, isn't any better from all I've read in the forums...huge frosting issues and duckbill issues.  Frigidaire I would avoid at all costs...I've gone through 2 "new" different model Frigidaire's all dying in less than 4 years.  Whirlpool brand has been my most reliable as a home consumer however they are small and not very attractive ... good luck on your choice!
Title: Re: Lg`s junk linear compressors
Post by: houptee on December 23, 2018, 08:13:53 PM
I have a 2017 Samsung side by side that I bought off a guy on craigslist really cheap because it that had a bad compressor. He got Samsung to give him a new machine and they tore off the data plate decal and cut the power cord off and told him to dispose of it.  When I ordered a new compressor the one that was sent was larger than the original and is louder but has been working for almost a year.

Then I bought a 2014 LG French door with the double access door setup (originally a $3500 fridge) got it dirt cheap because it had a bad compressor. When I took it apart the serial number on the LG compressor decodes to mfg 2017 so it has already been replaced once before and is bad again.


It runs and both boxes get slightly cool but the low side pressure fluctuates from 30psi down to a vacuum and then around 2psi and back to 20-30psi and then vacuum again, High side stays pretty steady about 100psi so I don't think its a restriction or the high side would be fluctuating and increasing but it stays steady.


There is no leaks since I ran vacuum pump for over an hour and then shut it off and left gauges on it overnight and it held vacuum for 12 hours so I assume the compressor is trashed only other part that might be bad is the 3-way valve since this is a dual evaporator fridge.
Title: Re: Lg`s junk linear compressors
Post by: panlonya on January 23, 2020, 12:59:54 AM
there are two types variable capacity compressors on domestic fridges: variable frequency (tree phase motor controlled by VFD- all three terminals have same resistance),  and variable voltage, called linear compressors, because there no motor, only resonance vibrator(only two terminals have 10Ohm  resistance). the linear compressors have fixed frequency like 53Hz, 56.5Hz, or 60Hz . you cant put compressor with different frequency. about LG linear compressor refrigerator- it very complicated and very smart device, but made from poor components and materials. if you replacing compressor, replace the condensation heating loop, and use vacuum gauge, during evacuation, to make sure no moisture in the system. yes you can put any compressor same capacity instead of linear, but you will have trouble led on the control board   flashing three times, but the front display do not indicate any problems, and all systems defrost, ice,.. will works fine. connect new compressor directly to board power input in series with low pressure switch set to -10"Hg. if your compressor have PTC starting components, or 3-in -one, you must add 5 minutes compressor delay relay, rated for start current, because if controller closes 3-way valve to pump down evaporators, the compressor goes into deep vacuum, and restarts shortly, after 3 way valve opens.