[trukkie]

Re: Schreiber problem

Yep there are two electrolytic smoothing caps one is in parallel with the 2 zeners and the relay coil, the other is in parallel with the PIC and its supply. Additionaly there is a decoupling cap across the PIC.

I didn’t mention them in my other post so that the intent of the circuit would be clearer in text.

I’ll get a photo posted showing the offending items and will draw up the schematic in a printable doc which explains all.

If the new boards are anything like the one posted on this site it looks like a complete redesign, the original is very different, make what you will of that.

cheers

[trukkie]

Re: MFI APM 6221 only freezes when fast freeze button depres

See the post – Schreiber problem

I believe the reason the freezer only works when pressing the fast freeze button is because the vibration on the PCB trips the relay in, eventually pressing the freeze button won’t work either.

[trukkie]

Re: Schreiber problem

ok I’ve completed the schematic and my original suggestion would appear to be correct.

The relay coil has two zener diodes in series, wired parallel to the coil which regulate the supply voltage from the bridge rectifier.
These are two 6v zeners giving 12v as the coil supply. Note since these are zeners and in parallel the supply voltage is clamped at 12v and can never go any higher.
Underneath these two zeners is another which is tied to ground and is in parallel with the PIC, this regulates the PIC voltage to 6v.
The PIC uses two transistors to short the 12v supply to the 6v supply when the relay is to be switched off.

So the relay is not powered to the specification in the data sheet. 😳

We have two possible causes:

1. The designers did a bad job and just thought they could get away with supplying half the voltage to the relay. 😡

2. The PCB manufacturers placed the wrong part and the 24v relay was fitted instead of the 12v. :rolls:

Either way this design was wrong as it left the manufacturers – this board will fail over time – some sooner, some later but they will fail.

I’ve contacted MFI who sold the freezer and will see how it goes.
If no joy there then it’s off to watchdog …celebrity beckons 😆

[trukkie]

Re: Schreiber problem

No there is no condensation build up and no corrosion.
The problem is that the relay can no longer trip, the cause is a PCB design flaw .
It’s a schreiber integrated into an MFI kitchen – I’ve no idea who makes ignis.

cheers

[trukkie]

Re: Schreiber problem

Yes it’s a mechanical relay – OMRON G5LE the data sheet is easily found with a quick search.

Sorry I meant coil not contact – contact is rated 250VAC.

I don’t have a schematic either but I am reverse engineering it and looking at it I don’t think the circuit is that clever – you have a bridge rectifier connected directly on the supply side and a PIC on the other. But yes that is possible – I’ll get the oscilloscope out and see if I can trigger on anything > 75{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d}Vmax(coil).

So the other possiblity then is that the PIC doesn’t maintain the surge voltage for long enough and again as the relay ages it starts to fail.

So still a manufacturing design defect hence the quiet recall.

Thanks for the input !

[trukkie]

Re: Schreiber problem

mmm and I think I know what the problem with the design is.
I did some measurements of the PCB and found the voltage across the relay is 12V. But the relay is rated 24V for the coil voltage.
So basically when your relay is fairly new it trips in as it should but as it gets older and becomes a bit more sticky it starts to fail to switch.

If your freezer has stopped working and the alarm is going off try shutting the door very firmly and see if the compressor kicks in.
It will then take the freezer down to the set temperature and trip out.
That proves that your thermostat is ok. The trouble is as the temperature comes up the relay can’t trip and your back to alarm again.
I found this worked every time with mine – not much use though other than as a debug tool 🙁

I tried contacting ISPRA controls – the pcb manufacturers but they wouldn’t respond.

Thinking about it, if what I found is correct then this would explain why MFI want the old boards back – no evidence!
This is a flawed assembly and the customer is footing the bill – I think I shall have a word with trading standards.

cheers

[trukkie]

Re: ADP 8242 Not loading enough water or dodgy thermostat

Thanks again P45

I took all the dishes out did a reset (just in case) and put it on a
wash empty

1 hr in and all looks fine

[trukkie]

Re: ADP 8242 Error Code E2

IT WAS A MOUSE !!!!!

found loads of mouse droppings and bits of rubber in the bottom tray

Perhaps Penguin could update the E2 failure page with mouse sabotage 😆

Cheers

[trukkie]

Re: ADP 8242 Error Code E2

Top tip !

cheers 😀

[trukkie]

Re: ADP 8242 Error Code E2

Hi all,

Well I finally got the dishwasher apart and found the pressure tube which runs from the sump to the pressure switch (loops over distributor)
was completely split in two.

Not sure if it has ruptured or a mouse! has got at it.

Anyway does anyone know where I can get a replacement pressure tube

cheers
Trukkie

p.s big thanks to P45 for the help

[trukkie]

Re: ADP 8242 Error Code E2

Oh dear !

looks like I’m missing the black flap then coz there’s nothing
black in the bottom of th sump – all nice white shiny plastic !

thanks for the info greg

off to the spares dept ➡

cheers

[trukkie]

Re: ADP 8242 Error Code E2

Cheers kwatt

Last question … honest

does anyone know where the transfer tube is on an ADP 8242 ?

Had a look into the sump – no black flap

just a hole to the left and can feel an inlet under the front bottom edge
of the sump – could be ?

ta

[trukkie]

Re: ADP 8242 Error Code E2

Cheers greg 😳

did a search for E2 but it returned 0 …

time to get the hose out !

😀

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