Archive for Refrigerator
Sub-Zero 642 flash “service” and “EC”
Posted by: | CommentsThe fresh food compartment set at 38 but will not go below 50 degrees the milk was going sour .
It was time to call for service…
Blinking “service” light and “EC” is a error code on Sub-Zeros. When a unit did not cycle defrost off 6 consecutive times in a roll. this a a common problem then a condenser is plugged with dust bunnies or a bad fan motor and the unit can not exchange heat . If the refrigerator can not remove the heat it can not keep the refrigerator cool and will keep running.
Remove three screws from inside the door. Take off the top grille held on by two springs. Two screws removes the compressor baffle. Make sure the condenser fan is turning when the compressor is running, If not it can often be started by a quick push in the correct direction. Take a look at the fan blade shape, it pulls air into the machine compartment. If the fan was turning but no air was flowing, the condenser needs to be cleaned. Make sure the unit is off when vacuuming condenser . Use a soft brush tool on the end of the vacuum and vacuum it top to bottom. do not move it side to side as you do not want to bend over the condenser fins.
After checking the condenser on this refrigerator this was not the case as it was clear and clean..
Sample of a evaporator ‘ Pop”
Next I check the back wall in the fresh food compartment. I noticed a ice build up on the left. A sure sign of a low gas situation. removed the light cover and the three screws at the top of the evaporator cover pull it forward and removed it. a large ice ball at where the cap tube enters the evaporator more evidence of a low gas problem. If there is low gas then there must be a leak as the system is hermetic sealed. Leak are found at the joints or in the evaporator. Sub-Zero evaporator made from copper and aluminum two medals that should not be touch each others as they cause a chemical reaction aluminum gives electrons to the copper ions. This causes the copper ions to turn into copper metal At the same time aluminum metal turns into aluminum ions. Al metal + Cu+2 ions —> Al +3 ions + Cu metal The solution ions become a metal (Cu). The new aluminum ions have different properties than the aluminum metal. The aluminum ions are not in a solid form which weakens the wall of the evaporator. Sub-Zero uses many different coatings to separate the two metals But this evaporator failure is common.
Oil residue in the drain trough below the evaporator is the nail in coffin. We need a evaporator.
A sealed system problem must be dealt with by an authorized technician or a lease a EPA certified technician , This repair is covered by Sub-Zero warranty.
Full Five Year Sealed System Warranty
For five years from the date of original installation, your Sub-Zero warranty covers all parts and labor to repair or replace any components that prove to be defective in materials or workmanship in the sealed system. The sealed system consists of the compressor, condenser, evaporator, drier and all connecting tubing.
Limited 6th Through 12th Year Warranty
From the 6th through the 12th year from the date of original installation, your Sub-Zero warranty covers all parts that prove to be defective in materials or workmanship in the sealed system (parts only). The sealed system consists of the compressor, condenser, evaporator, drier and all connecting tubing.
PN# 7009366 evaporator
PN# 7006964 Dryer
Replaced the evaporator and drier . recharged the system with 134A only 5.5 oz….and this Sub-Zero was back to keeping the beer cold and no more stinky milk.
Dead Fridge
Posted by: | CommentsThis fridge is two years old and not cooling, thankfully the customer had it emptied before I got there, rolled out with the back already off. It was drawing 1.22 amps and warm to the touch but not hot, the compressor seems fine, no frost build up and no audible hiss. Pierce the system and the needle doesn’t move, plug the power back in and it reads five pounds. Hook up the recovery bag and open the valve, the needle went back to zero and not even a hiss. So drag out the Nitrogen bottle, unplug the fridge, run it up to 200 psi and listen in the freezer, nothing yet. Grab the soap bottle while heading for the back and immediately hear the hiss I’m expecting. Reaching to feel the connections to the compressor I feel a draft blowing down on my wrist. The heat exchanger, hot gas feed and return are all within a few inches of each other and the escaping gas is coming from the ‘foamed in place’ back panel somewhere above them. Unfortunately nothing I can do to fix it.
This customer is lucky, in spite of being a year past the warrenty period the manufacturer is supplying them with a new fridge.
At FixYourBoard we repair a lot of GE fridge control boards with various component failures but there is one failure mode that we see often. This turns out to be responsible for a variety of seemingly random intermittent fridge problems that tend to be very hard to diagnose. Well, we came up with a very simple tool and procedure to isolate this problem on-site. It only requires one measurement with a DVM, nothing needs to be disconnected from the controller, only the control board cover panel need be removed.
Here I will describe the problem, how to construct this simple tool for about $3 and 10 minutes of your time, and how to make the measurement. This applies to the wide range of control board part numbers that look similar to this:
First: The Problem and The Test Strategy
The motherboard contains a 13.5 Vdc power supply that powers the relays, fans, dampers, etc as well as power to the temperature control board and dispenser board. There is a frequently occuring component failure that causes this power supply to still work fine under light loads, but lose its regulation ability under heavier loads. So suddenly, depending on the state of the fridge and what devices the motherboard is trying to energize, things go from working fine to … not so good … or major failure.
The test strategy is to make a voltage measurement on the connector (J4, pins 2-3) that supplies 13.5 Vdc to the other boards, AND TO DO SO UNDER FULL LOAD.
Next: The Test Load Device
Measure the voltage with a 25 ohm/10W shunt load to ferret out the problem (keep reading to see how to make the shunt load). A good board will see less than a few tenths Volt droop on this supply under load. A defective board will see a large drop in voltage (several Volts) when applying the load.
To be clear: If you see a supply voltage less than about 13.3 Volts under this condition then the motherboard has a problem. If the supply holds up under load, then the supply is good, but there could still be other problems with the motherboard. In a future blog I will deal with this. This is a quick NO-GO test.
If you think the supply may be bad but it’s not obvious, then also do a no-load measurement to check the difference. There should less than a few hundred millivolts difference between no-load and full load.
How to Contruct the Test Load
Here we build a 25 ohm, 10 Watt shunt load that plugs into the standard 3/4 inch spaced banana jacks on most DVMs. (OK, not all DVMs use this standard jack spacing, in which case you can add some short banana patch cords, or get a better meter). Following is a sequence of images showing how to construct the load, along with part numbers from www.mouser.com.
Last: Where to Measure
Backprobe connector J4 as shown below (the 2nd and 3rd pins from the edge). This is the 13.5 Vdc power supply to the other boards.
Summary
- Backprobe the 13.5 Vdc supply on the connector J4, between pins 2 and 3 without the test load
- Record the actual voltage (usually around 13.5 to 13.6 V)
- Plug in the test shunt load between your meter and probes
- Backprobe the same points and record the voltage under load
- If you see more than a few tenths of a volt drop under load, then the motherboard has a problem
- We can repair the control board for you at FixYourBoard
krazy Frigidaire Refrigerator
Posted by: | CommentsBrand new Frigidaire side by side in a brand new remodeled kitchen.. Customer said the box will turn itself off . She gets up in the morning with a warm refrigerator but its working other times…Sometimes No lights no compressor DEAD.. sometimes it work great.It works in the evening but stops at night and during the day…When I get there it is working good . second trip to her house and it is working good. I check everything thing and it is all working good…She is getting Mad and wants a new refrigerator. Asked for one more chance to put a recorder on the refrigerator my 3rd trip out..If I can’t fix it this time she is taking it back…So I grabbed a recorder and set her service call first thing in the morning… when I arrived at her house she opened the door and said you know where the refrigerators . So I open the refrigerator and it was dead …Alright now I can find out what is broke…pulled the refer out to get to the plug . The customer hear me pulling at the refer out, She said I will turn on some ” kitchen lights” as soon as the lights can on so did the refrigerator… The refrigerator outlet was hooked up to the lights .. So every time I came to service it she turn the lights on for me and the refrigerator would work…At night when she went to sleep she turned the lights out and also turned off the refrigerator.. Things that make you go Hmmm!!!!
Subzero 650 bottom mount No ice
Posted by: | CommentsHave a head ache with this one 4 year old subzero .. Customer noticed NO ice but the ice cream is still hard… then sees that the service light is on … resets the service light. by turn it off and then back on again.. Ice maker works again…I check history both box temp and evaporator temp both are good.. customer didn’t think the ICE light was blinking…history show the reset but no other errors…. Any Ideas? the FF evaporator I replace about 2 months ago..it had an ice ball on the cap inlet…but today it had a full evaporator and good pressures .