Cuchen WHK-V0620CP Rice cooker faulty

[Mr Prospecta]

Hi there peeps

I am new to this site and would really appreciate some help getting my Cuchen WHK-V0620CP Rice cooker fixed.

I brought this back from Korea brand new and without any international insurance policy.

I have only had 2 uses out of it. The 1st time all seemed absolutely fine until then trying to use it for the second time.
No power at all.
So I got someone who new a little bit about electronics to come and have a look.
What he did was bypass the primary circuit of the power transformer (the wire across 2 solder joints in the second picture), all worked well one more time, then nothing again. so now I have a lovely looking rice cooker brick sitting doing nothing.

I live in Uk which runs 240V Mains and I believe Korea runs 220V mains, so I thought there would not be a problem.
I have tried to contact Cuchen a long time back, hoping that they could source me another transformer, but have not had any reply.

I wonder if a different transformer is needed for UK?

Anyway any help would be extremely appreciated as it was really expensive and I would love to get this fixed.
Kind regards
Pete

 

[(*steve*)]

Take a sniff.

Can you smell any acrid smell? Does it seem to be coming from somewhere in particular.

I'm not enthused with jumpering across the winding of a transformer (If that was what happened)

 

[Mr Prospecta]

Thank you for your response.

It happened approx. 5 years ago so any initial smell has gone.

I have had another smell though and unfortunately there are no tell tail signs.

 

[shrtrnd]

That's the most complicated rice cooker I've ever seen.
From your description, my first question would be: Are you sure the circuit was
designed for 240VAC use? Does it say on the bottom of the unit what input voltage
is was designed for?
I've mentioned previously on this site, that the most common failure on rice cookers
that I've seen is the thermal fuse, in-line with the heating element.
Do you have DMM (Digital Multimiter) to check resistance (ohm) measurements in
an unplugged, de-energized circuit?

 

[Mr Prospecta]

As I said on the first post, it was brought in Korea.
I was right also that the input voltage is 220V AC, 60Hz

This would be the main problem I think, but is there a way possibly to change the transformer or other components to 240V AC rating.

Yes I do have a DMM.
The thermal fuse is fine which can be seen right at the bottom of the 3rd picture.

 

[(*steve*)]

Oddly enough, countries with 240V power are actually compliant with the limits for 220V power. Assuming the unit was designed correctly for 220V then it should operate safely and correctly with 240V

(For those that question this, I can go into a long and complex discussion complete with references. Briefly, the limits on overvoltage in a 220V system are fairly large on the up-side, and those on a 240V system are lower. It turns out that the upper voltage on both is within a volt of each other. This allows countries to "harmonise" to a 220V standard from their existing 240V standard by doing precisely nothing at all other than saying they provide 220V).

Note that I said "designed correctly".

So let's not worry too much now about 220V vs 240V.

Apart from that, I agree with shrtrnd and I think a testing of the elements and thermal fuses is in order (with power off).

 

[duke37]

There is another difference, the cooker was made for 60Hz whereas we have 50Hz in the UK.

As far as the transformer is concerned, this pushes up the flux by 20% which may be over the top. Another transformer made for 50Hz would be the best but what would be the voltage?

 

[Mr Prospecta]

Thank you all for your input.

Where should I start to look at after the fuse has tested fine.

 

[Mr Prospecta]

Anyone with an update?

 

[(*steve*)]

Are you *sure* your friend soldered a link between the pins of the transformer? It looks like the original to me.

The next test would be to measure the resistance across the power pins (of the unit's mains cord) to see what resistance is seen. If the device has a power switch, it should be in the ON position.