air conditioner high-low voltage error

[dodo41]

Hello friends. My air conditioner gives E6 error. It gives High / Low voltage error in the user manual. But when I measure the incoming energy, it's 220V. reading. I am uploading a few photos below. There is no energy in cable number 5 in the first picture. Does it have to be? The air conditioner comes from the outdoor unit to the indoor unit cable. I see it feeding the Out Fan in the air conditioner indoor unit. However, there is no energy due to the error, or is the problem arising from this?
I upload the photo of the card and cable distribution picture inside the air conditioner. Does anyone have an idea? For example, everything is normal but the circuit measuring the voltage is defective. Can we bridge this?
I measured the output of the transformer inside the air conditioner, and I did not come across a problem.

 

[marconi]

yes that is what I mean.

 

[dodo41]

I tried but it didn't work

 

[marconi]

That is disappointing.

I have not given up. I will contact you again tomorrow.

Marconi

 

[dodo41]

I'm waiting for you. Thank you

 

[marconi]

Right - we need to replace the blue potentiometer which is now broken. First I need to know the colours of the stripes on resistor R40.

Do you have a small soldering iron and solder? I would use one like this:

Antex S27J470 C15 15W Soldering Iron 230V Silicone Cable British Plug - https://www.rapidonline.com/Antex-S27J470-C15-15W-Soldering-Iron-230V-Silicone-Cable-British-Plug-85-5546?IncVat=1&pdg=aud-810679295195la-301834893510:kwd-301834893510:cmp-757438067:adg-44804851896:crv-207912323492id-85-5546:dev-c&gclid=CjwKCAjw7LX0BRBiEiwA__gNw3TLgyd3U4o4jVs-RCPANzj7yb5eCw8r9XPpqrirbpSxevBvdgNfhBoCWLMQAvD_BwE

What the last test did indicate - I cannot be absolutely sure - is that the mains voltage voltage sensing by the microcontroller detects 'too high' as well as 'too low'.

 

[dodo41]

Brown-Brown-Black-Black-Orange

What happens if I don't change the potentiometer?
I don't want to go out

Would it be a problem if we change the potentiometer another time?

 

[marconi]

I have contacted Rapid Electronics UK a supplier of electronic components which I use regularly. You can buy a replacement potentiometer from them. You need to buy some of these:

Suntan TSR-065-102-R 1K 30% LIN 0.1W Trimmer - https://www.rapidonline.com/Catalogue/Product?Id=68-1574

They are only 14 pence each so buy a few - just in case.

Be careful to order the item 68-1574 which has a resistance of 1kOhms.
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Could you measure the resistance of R40 for me please - it should be about 3000 Ohms.

If you send me you address in the PM(Private Message) area of the EF I will buy and send them to you - the cost is negligible so don't worry about paying me back.

Yes we do need to replace the potentiometer. Do you have a soldering iron and some solder?

 

[dodo41]

Yes, I have a soldering iron and some solder.

It values between 2.9 and 3 kOhm.
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However, it may take some time before I change the potentiometer due to Covid-19.
I may have problems in procurement.
I will try to act as fast as possible.

 

[marconi]

Procurement - what about using rapid electronics UK - I sent you a link in my earlier message?

 

[dodo41]

Okay. I will order.
Do you think the problem will be improved when you change the potentiometer?

 

[marconi]

Ref; Message #37.

Yes I do - but I cannot be certain - we have definitely found one thing that is wrong. There should have been a voltage between 9 and 12Volt sent from the potentiometer to the microcontroller - this was voltage V3. You measured V3 to be 0V.

Additionally, there should have been a voltage of 9V across R40 - this was voltage V2 - and you measured 0V. This indicated that the potentiometer was faulty - open circuit somewhere along its resistive track - so no current was flowing through the potential divider formed by the pot' and R40 across the 12V supply. The little power supply to this circuit was fine - it has an output of 12V dc - this was voltage V1.

The typical voltage range for an air con like yours is 198 - 242V. The voltage V3 is proportional to the input voltage and monitored by the microcontroller to detect whether the mains voltage is 'too high.

If it was my air con I would be changing the pot.

 

[dodo41]

First I will change the potentiometer.
Thank you.

 

[marconi]

The attachment might help you follow what we have been doing.

 

[dodo41]

I Replaced Trimpot. But I did not energize.
I'm waiting for you, Mr. Marconi.
Please review and tell me what to do.
I set Trimpot to Full center.

 

[Mike Johnson]

Impressive diagnostic's and information, hope it works after all this.