CDA CW195/1 intermittent power problem – help!!

[itgoodson]

So glad I’ve found this site. I’m tearing my hair out with this dishwasher…

I have a CDA CW 195/1. The current problem is that the power is intermittent. It cannot get more than 5 minutes in to a cycle before the power starts flickering on and off. I am currently sat looking at the dishwasher on its back with the control panel flopped forward with the power light coming on for a minute or so and then going off for a few seconds repeatedly. There have been times today when it has stayed off for a long time only to come back to life.

I am relatively new to all this so please bear with me. I have used a continuity tester to check the wires and the switches from the power to the board and there is a constant ‘beep’ from the tester. I have ‘nipped’ and WD40ed the connections to the between the power supply and the board to make sure they are tight.

There are no fault codes logged in the machine.
I have tested a hairdryer in the socket and that runs fine so supply to wall is ok.

Am I right in thinking that any faulty wiring or loose connections elsewhere in the machine won’t cause the power to flicker on and off? Or could a loose connection or a dodgy part be causing this flickering on the board?

The power problems are not throwing the switch in the RCD box.

Does this sound like a faulty PCB? Or should I be looking for something else?

A bit of background which may help:

Bought the machine second hand, looked in good nick to the eye. First problem was a filing problem – solved by nipping connector for wire in to PCB.
Then the circulation pump went. Bought new one, fitted it, worked fine for a week.
Then power went out. I discovered a leak underneath where I hadn’t put hose in to new pump securely enough. I dried everything off and power came back on.

Worked for two days and then power started being intermitent. This time there was no leak, everything dry. And this is where I currently am with it – faffing about with a continuity tester, a hairdryer, WD40 and a pair of long nosed pliers. I thought it had gone completely this afternoon when power seemed to go off for ages, but somehow I have managed to get it to the stage where power stays on for a minute then goes off for a few seconds and repeats.

Any help really gratefully recieved. Having shelled out for the new pump I really want to try and make this work – I hope it’s not a faulty control board.

[Martin]

Re: CDA CW195/1 intermittent power problem – help!!

A capacitor on the PCB may have failed? Look closely at the surface components and if a capacitor looks swollen or has a domed top then out with the soldering iron. 💡

[itgoodson]

Re: CDA CW195/1 intermittent power problem – help!!

Over night the thing seems to have improved – I’m currently 10 minutes in to a cycle. But I know it won’t last. It’s doen this before.

Thanks – forgive me, I am complete novice really (but stupidly enthusiastic!) – would a blown capacitor not make the power fail completely? Or can it cause this intermitent power problem that I have?

Cheers

[Martin]

Re: CDA CW195/1 intermittent power problem – help!!

The latter.

[itgoodson]

Re: CDA CW195/1 intermittent power problem – help!!

Ok – this afternoon power completely failed to the board. I have checked with a continuity tester power from the plug to the connectors on the board and live and neutral are both fine.

I have taken the control board out. There is nothing completely obvious to me, Here is a picture of it. Can anyone spot anything dodgy looking about these capacitors? There are black marks on all the capacitors – but they look like ink marks. I suppose if I was going to guess at one being the problem then the one farthest left in the picture looks ever so, ever so slightly raised on top compared with the completely flat tops of the others. There is no sign of any obvious leakage on top or under the board.

Cheers

[agwarn]

Re: CDA CW195/1 intermittent power problem – help!!

Are the wires in the door ok?

[itgoodson]

Re: CDA CW195/1 intermittent power problem – help!!

I hate this stupid machine!

Yes wires in door are ok – cheers

I replaced the capacitor farthest left. It seemed to work a treat as power came straight back to the board.

However, now the thing keeps triping the switch in the RCD box. It gets to the point in the cycle where the tablet is ejected and then – I presume – the heater starts to heat up the water going through teh pump (on this model the heater and the pump are connected as one).

So am I right in thinking the problem probably lies with the heater? What could teh problem be? From the outside the heater looks fine, no sign of any obvious corrosion. The cable connection to the heater is sound. I’ve tried drying it off with a hair dryer in case there was some mositure. What else should I be looking for?

[itgoodson]

Re: CDA CW195/1 intermittent power problem – help!!

Update and further question:

I have used a multimeter to check the heater – it seems to read a steady 26ohms. It looks in fine condition – no signs of any corrosion. Though when I used a continuity tester between the live or neutral and earth there was a short ‘beep’ from teh machine (though not a continuous one)

I have used continuity tester on the wire between the heater and control board – all is well

I’m just wondering whether my bad soldering on the control board is causing the short. I’ve looked at the solder and it doesn’t appear to touch any other connections. But they might be a bit loose. Could that cause it? Is it the case that certain capacitors on the board are only called in to use on certain parts of teh cycle (i.e. problem with soldering will only show up when the heater is called in to use for instance?)

Cheers

[Author]

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