Aircon won't turn off.

[ABCDBKK]

I had control boards eventually fail on 3 air-cons. Same problem, fan coil unit shuts off normally, but compressor outside stays on after unit being powered off.
 

The first 2 they charged 2,000+ Baht each to replace. On the 3rd one they had run out of spare control boards so the guy quickly soldered it for a couple of minutes and then it was fine again and no longer needed replacing. Then charged only 500 Baht for the repair service on that one. This tells me they all probably could have been soldered and not replaced.

 

A nice little business they have going with control boards that all eventually tucker out, but could actually still be repaired and don't really need replacing. Hmmmm...

Edited April 5 by ABCDBKK

[KannikaP]

14 minutes ago, giddyup said:

You know what? I think I'm going to go with the breaker idea. I only need to run it a couple of times a month for 30 minutes, so not a big deal.

What warrants a 'turning on'?

[giddyup]

7 minutes ago, ABCDBKK said:

I had control boards eventually fail on 3 air-cons. The first 2 they charged 2,000+ Baht each to replace. On the 3rd one they had run out of spare control boards so the guy soldered it for a couple of minutes and then it was fine again and no longer needed replacing. Then charged only 500 Baht for the repair service in that one. This tells me they all could have been soldered and not replaced. A nice little business they have going of control boards that all eventually tucker out quickly. 

What was the new part he soldered in?

[ABCDBKK]

Just now, giddyup said:

What was the new part he soldered in?

Nothing. He just did a bit of soldering on the control board AFAIK. I assume some faulty electrical connections were reconnected. 

[KannikaP]

1 hour ago, lopburi3 said:

What brand is it?  Have you turned off main breaker for few minutes and then turn on and see if it starts again?  That will work for some board issues (until next power failure).  But if have to replace board 3k is likely a good price - we paid 5,500 few weeks ago after voltage drop to 108v for extended period during the night.

Would the whole a/c unit not shut down at 108 volts, same as your lights, telly, fridge?

[giddyup]

Just now, KannikaP said:

What warrants a 'turning on'?

True or not, they all suggest that aircon be run for a while regularly to keep them in good nick. All I know is that things start to fail when you don't.

[KannikaP]

35 minutes ago, giddyup said:

True or not, they all suggest that aircon be run for a while regularly to keep them in good nick. All I know is that things start to fail when you don't.

That's what my Mrs keeps telling me!

[SAFETY FIRST]

2 hours ago, giddyup said:

The rarely used aircon in the lounge won't turn off. The compressor does but not the cassette or whatever it's called that has the fan inside the room. The technician says it needs a new control board or something that costs around 3000 baht. Does that seem about right? He replaced something that sounds like a capacitor and regassed the compressor and replaced a globe that lights up when the aircon is running for 1400 baht.

If it's running fine, cooling etc. just turn it off and on at the circuit breaker. 

 

[KannikaP]

48 minutes ago, giddyup said:

True or not, they all suggest that aircon be run for a while regularly to keep them in good nick. All I know is that things start to fail when you don't.

Running it doesn't seem to be the problem. Shutting the 4..ker down is!

[lopburi3]

50 minutes ago, KannikaP said:

Would the whole a/c unit not shut down at 108 volts, same as your lights, telly, fridge?

Actually fan/lights ran normally (but slow for fans) even down to 99 volts.  LED do have advantage.  This happened about 0100 so TV not on and refrigerators all stopped.

[xtrnuno41]

So what is broken now? IT works but only doesnt shut off by remote?

Does other functions work with the remote? Like put it only on fan? Or activate "swing"?

With activating "swing" and it starts to swing, you know remote and receiver are working.

If functions arent working with remote, something wrong with communication? IS it the remote then or receiver?

How you treat your remote? You get it damaged, falling , sitting on it? Could happen.

Had a new remote controlled light, it only worked in a specific angle?! That is a miss alignment. Maybe yours too?

Try different angles. Someone put a piece of paper on receiving window?

Does you airco work when you push buttons ON airco, if there are?

 

Like Crossy said, are there mechanical relais, they can "hang". Of course it can be broken complete.

If you are going to tap the relais GENTLY, switch off power complete!

Or when you do "live", use a non conducting material. like a plastic or wooden spoon or something like that.

Be aware where your hands are then all time! Safest way is to switch off power.

 

SO buy a new motherboard? Still in guaranty or not? Airco works, but need manual control, can you live with it?

It is rarely used, you said.

[Gandtee]

In thirty seven years here I've never had aircon. Fortunately the house is built on stilts and we get plenty of air flow. Even so, the fans are working where needed. Especially at night. I wonder how much I've avoided paying for electricity in that time.😉

[transam]

7 minutes ago, Gandtee said:

In thirty seven years here I've never had aircon. Fortunately the house is built on stilts and we get plenty of air flow. Even so, the fans are working where needed. Especially at night. I wonder how much I've avoided paying for electricity in that time.😉

How much do you spend on mosquito and bug cream......?.....😬

[Gandtee]

2 minutes ago, transam said:

How much do you spend on mosquito and bug cream......?.....😬

With mosquito nets on all windows and doors, much the same as those with air con. Only when going out.

[bluejets]

Fairly common fault in the remote is the button looses it's conductive coating and no longer works.

There are claimed fixes which work on youtube or instructables but never in real life.

Obvious fix there would be a new remote.

One can check if it is working by pointing at you mobile phone screen while pushing the button in question.

The IR light can be seen while the phone camera is active.

[rexpotter]

11 hours ago, giddyup said:

What was the new part he soldered in?

Exactly what I figure. Its even possible the guy who serviced mine pulled some BS while I wasn't looking knowing he would be back. Even using those high pressure cleaners carelessly gets water when you do not want it.

[Crossy]

51 minutes ago, bluejets said:

Fairly common fault in the remote is the button looses it's conductive coating and no longer works.

There are claimed fixes which work on youtube or instructables but never in real life.

Obvious fix there would be a new remote.

One can check if it is working by pointing at you mobile phone screen while pushing the button in question.

The IR light can be seen while the phone camera is active.

 

Good advice on testing the remote.

 

Lurking in one of the earlier posts is the fact that the manual on/off switch on the unit also doesn't turn it off. 

 

I'm suspecting a stuck relay, but without poking around on the board with a multimeter we are fumbling in the dark.

[Yellowtail]

If the power button on the remote turns off the condenser but not the evaporator? 

[giddyup]

29 minutes ago, Yellowtail said:

If the power button on the remote turns off the condenser but not the evaporator? 

Yes

[Fruit Trader]

The indoor unit fan not stopping when off button pressed is a common fault on AC's that electronically switch the fan using a triac (electronic switch). The triac becomes leaky or fails completely resulting in a constant connection from power line to fan motor.

The usual fix is to replace the control board or in some cases the board is taken away for component level repair. The average cost of Samsung control  boards is around 1800 Baht plus how much the install throws on top for the service.   

Its a good idea to disconnect AC's in rooms that are not used for long periods ideally via a double pole local isolator. This isolation takes away the standby power consumption and limits electronic damage from line spikes and surges.
 

Edited April 6 by Fruit Trader

[bluejets]

16 hours ago, Fruit Trader said:

The triac becomes leaky or fails completely resulting in a constant connection from power line to fan motor.

 

In fifty years I've never seen a triac that is "leaky".

As far as "fails completely" ...again fifty years show they go open.

[sammieuk1]

I will send my Mrs. round she will be sure to find a way of turning it off 🤔

[Denim]

On 4/5/2024 at 4:51 PM, giddyup said:

New.

 

Could be a faulty remote, even with new batteries. Try to use a universal remote to see if it works. I always check out the cheap and easy options first and often save myself a lot of money.

[Crossy]

1 hour ago, bluejets said:

In fifty years I've never seen a triac that is "leaky".

As far as "fails completely" ...again fifty years show they go open.

 

Yeah, failing open is my experience too.

BUT

Once, many years ago (I was about 12 so early 70s) we had an incandescent lamp fail spectacularly when it was on (nice pop, broken glass). Afterwards the dimmer it was controlled by would only operate at full brightness, so in that case I'm assuming the triac went short. But as I said, that's once in many years, other times the beasts have gone open.

[Yellowtail]

4 hours ago, Crossy said:

 

Yeah, failing open is my experience too.

BUT

Once, many years ago (I was about 12 so early 70s) we had an incandescent lamp fail spectacularly when it was on (nice pop, broken glass). Afterwards the dimmer it was controlled by would only operate at full brightness, so in that case I'm assuming the triac went short. But as I said, that's once in many years, other times the beasts have gone open.

Wow, you had a dimmer in the early '70s? You must have been rich! I remember my dad replacing the switch in the "dining" room back in the '60s, and bragging it was a mercury switch...

[Fruit Trader]

7 hours ago, bluejets said:

In fifty years I've never seen a triac that is "leaky".

As far as "fails completely" ...again fifty years show they go open.

 

Interesting because triacs are born leaky.

Some triac failure conditions in air conditioner fan control = unacceptable leakage, half wave, short or open. Fail closed = common. 

 

 

 

 

 

Leaky triacs available upon request, shipping negotiable.