Hi I have a Blyss Dehumidifier (WDH-316DB) that worked for two years. I left it 6 months. Now when I turn it on the screen lights up and the unit appears to start up .. then it dies. Only unplugging it and replugging it , switching power on resets it. It appears to still have current as the full tray indicator light goes on and off when it is removed. Is this a capacitor issue? Can I test anything. This is a video link to it

. I have also attached a pic of the circuit board. There seems to be white residue between elements on the board.

I hope this is the right forum for this but any ideas would be greatly appreciated

 

Welcome to AAC.

Those capacitors do not look bad. "Re-capping" is not a solution.

It acts as if it is booting, getting some error message, and shutting down. What type of error message? Coolant (Freon) low? Motor won't start? Faulty temperature sensor?

Is it possible the screen or something else is powered by a battery? That is may be very unlikely, but would be an easy fix. A low battery could lead to such shutdown.

 

Thanks. Can you see the video link I attached? There is no error message the screen just fades out. I will have a look for a battery somewhere tonight.

 

Yes, I viewed the entire video. That's where you can see that the screen is working, and it boots or at least starts to boot. Something is then shutting it down. you could try unplugging stuff from the board and see what happens. How many plugs go to or from the board? Picture?

 

Right. Picture attached- only one goes to the screen- see the red plug top left of attached image. I will try unplugging bits - thanks.

 

Red plug doesn't need to be tested, screen is OK. CN7 is humidity. I suspect that is OK.
CN6 is a light duty power (fan?). Probably not the issue (a guess).

I would focus on:
CN3 and CN4 look like maybe sensor connections. Lack of a sensor may cause failure to start and shutdown.

The heavy duty (spade connectors) look like power connectors. An overload on them may cause failure to start. Can you identify which ones go to the compressors versus supply current from the plug? I would not disconnect those that go to the power plug, just the ones that go to the compressor.

Unplugging the connectors will not likely cure the problem, but it may help find the part that causes shut down. I would start with the connections to the compressor.

 

brilliant thank you . I will try this sequential test tonight... makes lots of sense

 

Ok so I have unplugged all the connections ( to the fan, the compressor, the vent ) . With just the red plugged into the screen. It still does the same thing. I took the housing off of the screen to find a battery but only switches and circuit board here.

Can’t think what else to try?

 

Also “water” is the float switch. I unplugged this and it is the same ( plugged back in in pic to stop beeping)

 

I would plug everything back in that probably works, like the water level switch. I suspect after boot up, all of the sensors are checked. If water level is high, that usually gives a problem signal. The display stays on, but the compressor doesn't start. Have you tried it will all the plugs installed and only the motor leads disconnected?

The most common cause for dehumidifiers to fail that I have seen is loss Freon. The ones I have had (several) simply overheated and shutdown. Don't know about where you are (Australia/New Zealand?).

 

OK thanks I'll try with only the motor leads disconnected. I am in the UK. Another thing that I have thought is that there is a outlet for a hose rather than the tank. There is cap for this. I took it off and had the humidifier in the sink for a while with a short hose on on the boat. It may need this cap to be on (but I can't see any sensor). The trouble is the cap is on the boat, on the mooring - i will try to retrieve this weekend. Thanks for your help

 

That arrangement with a hose barb and cap is pretty standard. In the machines I have owned there is no sensor associated directly with it. Imagine a Y connection for the condensate. If one branch is closed (i.e., hose connection) it all goes to the bucket. If the hose connection is open it goes to the hose (mostly). If the water level detector in the bucket indicates full, the dehumidifier will not run and will act as if the bucket is full regardless of whether there is a hose connected. That situation can happen, for example, if the hose gets clogged.

 

yes I think that is right.. the hose cap is not the issue here

 

Get a DVM, and measure the voltage DC voltage supply at CN5.

It's a Switchmode PSU so it may give out various voltages.