Fridge Not cooling, Problem solving.....

[dishman]

Ok, my trust Samsung fridge/freezer is having a fridge temp issue,

It is a Samsung RL39WB. Here is the service manual.

SAMSUNG RL39WB SERVICE MANUAL Pdf Download

View and Download Samsung RL39WB service manual online. RL39WB refrigerator pdf manual download. Also for: Rl39eb, Rl36eb, Rl36sb, Rl39sb.

www.manualslib.com

Now, the fridge has run perfectly for years. But, last week I left the freezer door open for a few hours by accident.
After closing it, I noticed the fridge was no longer cooling.

Having repaired the fan before, I suspected the exchanger was all iced up at the back and I assumed to be impacting airflow.

And it was fairly compacted with ice, nothing extreme, but I defrosted it and put it back together but....no go. Still a warm fridge and a cold freezer.

I have since checked the fan, damper operation and fridge thermostat. All of which seem to be operating normally.

I get a multimeter resistance reading on the thermostat (6.5kohms?) which rises when I introduce something cold to the end.
I can see the damper spinning and being static when trying to regulate the two.
Fan spins normally and I can feel good airflow out of the vents in the freezer.

What I can't feel however is airflow into the fridge vents. Nothing at all. Even when the damper is open/spinning it seems.

So.....what am I left to consider?

Ice blockage in the fridge ducting?
(Would that not have eventually melted once back to normal operation with the door closed?).

Fan motor spinning....but not fast enough?

 

[big-all]

by default automatically go for defrost as the simple cheap option for 24hrs frost free or 2-6 hrs aided by warm water bowls to aid defrosting

 

[JohnD]

How long did you defrost it for? Both doors open?

 

[dishman]

I did not do a long slow defrost. Mainly because of limited time due to a full freezer.

I basically did a speed defrost with hairdryer assistance of the exchanger in the freezer section only.

But, I'm surprised if there is an ice block in the ducting as that section does not seem cold enough to maintain a block.

But....with the freezer section operating perfectly, it's now my only strong conclusion.

My only other theory is that the damper is not opening long enough to cool the fridge section. But, even when it is open, I really can't feel any airflow through the fridge vent, which would mean blockage or fan power.

 

[foxhole]

Did you notice any clicking when opening door ? When door is open the fan cuts out and if obstructed by ice can make a noise as it stops.

 

[dishman]

I can hear relays clicking when I open the door. The fan runs fine, no catching on ice. I can feel airflow in the freezer section. I can also see the damper rotating or staying in close and/or open position.

Freezer is staying perfectly cold. No over-icing/build-up.

It's looking like a slow defrost is needed to perhaps exclude the ducts to the fridge.

 

[ericmark]

I used a fridge/freezer for brewing beer, I would start in freezer compartment with an external thermostat which would keep the fermentor at 18ºC 40 pints takes some cooling and often it would go in at 20ºC so would take a few hours, air temp would drop to around 5ºC but the fridge never cooled, it seems there was some thing in the unit which prioritised the freezer, and until freezer was around the standard -18ºC the freezer simply did not work, this suited me, half way through fermenting I would transfer to fridge compartment as by that point only needed to heat.

I don't know if all fridge/freezers work that way, but if you have not got freezer down to -18ºC then very likely fridge will not cool.

 

[dishman]

Update!

Finally had a chance to do a full 24hr defrost and trace all the vent paths using strimmer wire and a hair dryer to do a vent test.

I traced the problem to the return vent from the fridge to the freezer. The strimmer wire was getting stuck on something cold.

Turns out it was compacted with ice. The outlet was only visible after a full defrost. Even after 24 hrs was ice compacted in it. I mist have missed it on the first defrost.



That tiny plastic slot.

Teaches me for leaving the door open by accident.

Hopefully now I will get the proper flow of air between the two compartments.

 

[big-all]

thanks for the update much appreciated

 

[dishman]

i have a further curious issue that is "fixed" but not sure why it is happening.

The fridge/freezer fails to power up, somewhat inconsistently.

Even thought it finally powered up, I can't quite work out why it was doing what it was doing.

After plugging it in, and pressing the power button, I would get a single flashing green LED light on a bank of 4.
With this flashing light, nothing else would power up. No internal light....nothing.

This is now an older model samsung so there is very little info I can find out about fault codes.

At first I thought this might be some kind of issue with defrosted water causing an issue with thermostat connectors on the wiring loom or something. As after cleaning all the connectors last time it did this, it seemed to power up fine.

But subsequent power offs and ons have yielded the same issue, with no link as to the cause.

For example after this defrost and clean, I finally powered it up. Nothing......just the flashing light.

I waited a while then tried and magic, all powered up fine. Then I realised I needed to do something, so powered it off, and then it would not start up again....just the green flashing light, no matter how many times.

So I left it for the night.

Today, same issue....attempted start, just a flashing light. Then, suddenly all is fine and powered up like a champ.

Any ideas what this could be?

My only wild stab in the dark is some sort of starting capacitor issue to get the compressor going initially? Somehow it's capacity is depleted or failing? But once running it is fine?

 

[JohnD]

the flashing light is probably a fault indicator. Which LED it is, and how many times it flashes, is probably a code.

Commonly the onboard "computer" circuit board monitors error conditions and commands the flash.

I'm tempted to say turn it on and leave it on.

There might be a fault in the auto-defrost, or it might be damp related.

of you goggle for "error code flashes samsung fridge freezer" you may find something, or it may be listed in the instructions

 

[dishman]

Yeh, there was no "code" as such.

The light just blinked indefinitely. It was as if there was something not meeting start requirements.

It eventually started though and seems to be performing flawlessly.