Thank you Dadoes. What other problem do you think I have to suspect?

Do you think I have to try replacing condenser motor?

I also just realized that even the noise problem wasn't fixed. It came back even more noisily.

The noise could be the circulation fan in the freezer section hitting the accumulating frost/ice.

Other parts that can cause defrost failure are the defrost heating element and thermostat.

You didn't provide the model number of the your refrigerator so I have no way to look up details on it.

On mine, a Westinghouse, it was the defrost heating elements that were burnt out. Access wasn't easy, but, with patience, I replaced them and it's still going good 10 years later.

YMMV

Thank you! This is the model number. And it's Kenmore.

I already bought defrost heater & thermostat kit.

You bought them but haven't installed?

Where'd you find a defrost thermostat? SearsParts tags it as NLA, as do some other sources I checked.

Have you done electrical troubleshooting on the components?

Your refrigerator is sourced from Sanyo.

I am not sure if I have to replace defrost heater & thermostat kit. I also have to learn how to replace them (Searching youtube).

These are the things I bought.

https://www.amazon.com/gp/product/B01M4NZM9D/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B07NF3LGZ9/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1

What do you mean "electrical troubleshooting on the components"?

You randomly selected some parts via Amazon? GE parts for a SxS unit, to fix a top-freezer refrigerator that Sears sourced from Sanyo? Good luck with that. The defrost thermostat may not operate within the correct temperature range, and the defrost heater kit won't fit on it at all.

Where'd you get the aforementioned defrost timer? Wrong part? Are you sure the timer was bad?

This is your unit at SearsParts:
564.461042100 Parts Diagrams

The defrost element is #46 on the "Unit" diagram .. Part Number 302598, substitutes to 303107. I don't find it via search anywhere except Sears.

The defrost thermostat is #44. Part Number 302596. Tagged as no longer available.

The defrost timer is #51. Part number 302603. Sears says no longer available. I found it at DiscountAppliance.Premium-Outlet.org but the Purchase button goes back to Sears, so nope.

The element is not directly tagged as NLA but it could be ... SearsParts is known for items not showing as not available until after submitting the purchase. I've had that happen a couple times. They charged my ccard immediately, then advised the item is on backorder, repeatedly for weeks, and I had to contact them to cancel the order and get a refund on the charge. I wouldn't order anything from SearsParts any longer without calling them directly to check on availability.

Electrical troubleshooting means test the defrost heating element and thermostat (and defrost timer) with a multimeter (volt/ohm meter) to confirm if they're bad.

My suggestion is that you call an appliance service that can properly troubleshoot the problem and may have experience to find substitute parts if anything is needed.

Or buy a new refrigerator.

How old is the fridge? Have you tried cleaning out the tubes that run from the freezer to the fridge?

Thank you so much

https://www.amazon.com/gp/product/B00DM8M9OC/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 This is the defrost timer that I bought and put into place yesterday.

And the defrost timer that I used to have is this:

This fridge is more than 6 years old. I came to this studio 6 years ago.

And if Sears doesn't have thermostat and defrost timer on their website anymore, does that mean I can't find them on Amazon or elsewhere?

Hi, It's been awhile sense I last worked on refrigerators. I would suggest you don't buy any parts until you know what the problem is. You may have a plugged up defrost line. That would allow water to get into the vents and give the problem you are having. Check the condensate pan at the back of the fridge, could be on top of the compressor. If it is dry unplug and defrost the fridge and clear the lines.

Good Luck Woodbutcher

That defrost timer may work if the timing and internal circuits are the same as the original. The terminal wire/color coding is different. Did you connect the wires by position as per the original?

It's 16 years old per serial number decoding.

Per the suggestion above, the defrost drain from the freezer could be clogged with slime/muck (a common occurrence). That'll cause defrost condensate to pool on the floor of the freezer and possibly obstruct the airflow ducts when it re-freezes after a defrost cycle ... although water would normally be dripping into the fresh food section and accumulate on the bottom under the crisper drawer(s).