Ideal Icos m3080 blowing fuses

[onlyfitidealboilers]

Check coil on gas valve 4.2k when your doing the short circuit test through you multi plug on the boiler it's only testing the transformer and cable, die to all the relays etc on the pcb, your best bet is to test every wire resistance to earth and test each component. Tbh would not Supprise me if the pcb you fitted is blowing fuses! Good luck!

 

[Agile]

Static DC resistances (Multimeter readings) are:

L-E 4.3 MΩ
N-E 5.4 MΩ
L-N 72kΩ

which don't immediately ring alarm bells.

My immediate response is to wonder why your first two readings dont differ by 72K Ω

What is Amy doing for you?

Tony

 

[windbagUK]

Check coil on gas valve 4.2k

Thanks again.
Will do, plus check as many resistances as possible.
Apart from the main 110 Ω on the fan (blue-red), anything else to look for on the other 3 pins (are they fan motion sensing related?)

All the others look straightforward to test.

Am happy with external measurements, but if anything internal to the the PCB cover is an issue, I can get a replacement PCB as this one has a 12 month warranty.

That is why I ask if I can power up the PCB with nothing connected but it's mains input. If that shouldn't inherently damage the PCB & it then blows a fuse then I'll just send it back.

Good luck!

Thanks

 

[DP]

My immediate response is to wonder why your first two readings dont differ by 72K Ω

What is Amy doing for you?

Tony

What do you mean tony?

 

[windbagUK]

Static (DC) resistances with multimeter:
DC gas valve: 3.95 kΩ
Overheat thermostat: ~0Ω
Control Thermistor 25.9 kΩ
Flue Thermistor 22.7 kΩ
Fan 107Ω
(No measurements made across combinations of yellow/pink/black lines as I don't know what I'm putting the MM test voltage onto - but all isolated from earth)

All Neutral & Live connections are fully isolated from Earth (both sides of the filter, including black lead).
The previous measurements of:
L-E 4.3 MΩ
N-E 5.4 MΩ
were incorrect - that was with the programmer still connected.
The measurements now give effectively open circuit from the supply side when the PCB is disconnected (but filter is), 7.5MΩ or open circuit when the PCB is also connected (depending on polarity of test leads).

All other connections are isolated from earth, except these which gave effectively zero resistance:

Flame electrode detection earth (obviously)
DC Fan red connection

The only one that surprised me was the fan red line.
I disconnected the fan plug, and this remained the same, so it is not a feature of the new fan.

 

[matt1e]

The only one that surprised me was the fan red line.
I disconnected the fan plug, and this remained the same, so it is not a feature of the new fan.

it shouldn't be grounded
which plug did you disconnect from
fan end or pcb?

 

[Agile]

What has Amy done to help you?

Tony

 

[swesandrew]

Windbag, the circuit boards are highly complex when
LSI chips are used as they are on this board. Even majority of Ideal chaps nd ladies would be hard pushed to decode the programme housed in the chips on the PCB. To think someone out there with nothing more than a multimeter and a soldering iron could refurb such a board stretches the imagination somewhat. I as a heating engineer would want to plug in a new board that has not been touched by someone who thinks they can refurbish complex boards

Good luck in your quest to get this dragon to breath fire again

Its nearly always the transformer a really really common fault on these

 

[windbagUK]

What has Amy done to help you?

Tony

I sent you a message about this to your email as you request on your profile.

 

[windbagUK]

The only one that surprised me was the fan red line.
I disconnected the fan plug, and this remained the same, so it is not a feature of the new fan.

it shouldn't be grounded
which plug did you disconnect from
fan end or pcb?

Both. Same result (tested at the plug that would go into the PCB).

 

[windbagUK]

Its nearly always the transformer a really really common fault on these

As I said, if it's inside the PCB covering, that is under warranty. Given that, opening it up would be unwise.

 

[matt1e]

If there is a short from red to earth measured on the harness with both ends disconnected then there is a problem with the harness
I would also check the pcb for signs of the pcb tracks burnt out too as it sounds as though they have probably took a hammering by now

Matt

 

[onlyfitidealboilers]

Water anywhere dripping? Wat is the resistance of the spark gen
Should be 2.5 MOHMS ?

 

[windbagUK]

Being as I had to get on, I went ahead and ran up the PCB with only the mains input connected (all else disconnected).
It blew the onboard mains fuse immediately. The seller is exchanging the PCB.

But I do need to bottom out the red fan line being a short to earth in the cable run between the PCB connector and the fan connector, if that truly is operationally a no-no.

 

[windbagUK]

Water anywhere dripping? Wat is the resistance of the spark gen
Should be 2.5 MOHMS ?

No water drips - totally dry, very clean, no corrosion.
My measurement for the resistance from the ignition electrode to earth gave open circuit at the disconnected spark connector plug - which is what I would expect.

Onboard PCB problems are under warranty, so I'm not going there.