How to go about checking this PCB

[mainline]

Do you mean the ignition coils or the 24V one because that was hot. It was first thing I noticed when it stopped working.
The 24V one is quite massive. I can hook up to it easily and see if there is voltage drop on ignition.
Hooking up to the little ignition one is complicated.
I'm off to shops on Town street to resolve the resistor. They just arrived.

The LZL-24H is a relay.

Yes I meant the ignition one.

 

[david74]

Well at least you got some ignition, pity it was from the wrong place.
The capacitor may have been the source of the short so you could change it along with the resistor again.

What I will do when I get the replacement board, first I will try it in the machine to see if that works.

If it does, then I will replace the resistor and capacitors and compare readings with working board.

Once it does match, I will try it in device again and if works, put it on eBay half price perhaps to recover some money. Or perhaps I could do something more sinister and send the new one back under 14 days return policy.

Also I will maybe develop understanding how certain electric components work together apart from one being blown out when the other is short.

 

[Avo Mk8]

What I will do when I get the replacement board, first I will try it in the machine to see if that works.

If it does, then I will replace the resistor and capacitors and compare readings with working board.

Once it does match, I will try it in device again and if works, put it on eBay half price perhaps to recover some money. Or perhaps I could do something more sinister and send the new one back under 14 days return policy.

Also I will maybe develop understanding how certain electric components work together apart from one being blown out when the other is short.

Realistically, unless you can get hold of the circuit diagram, the board is "beyond economic repair".
R41 is now a gonner. Things burning up are quite likely symptoms of a fault elsewhere, not the actual faults. You may have to detach components to individually measure them, and doing lots of that could end up damaging the pcb or components.

Some of us like dabbling with electronic repairs, and it can often be successful with simple faults like droppers in power circuits, but I suggest a reality check here, and it would be more worthwhile checking there's nothing wrong in the boiler that's going to blow up the next PCB.️

 

[david74]

Realistically, unless you can get hold of the circuit diagram, the board is "beyond economic repair".
R41 is now a gonner. Things burning up are quite likely symptoms of a fault elsewhere, not the actual faults. You may have to detach components to individually measure them, and doing lots of that could end up damaging the pcb or components.

Some of us like dabbling with electronic repairs, and it can often be successful with simple faults like droppers in power circuits, but I suggest a reality check here, and it would be more worthwhile checking there's nothing wrong in the boiler that's going to blow up the next PCB.️

That is a valid concern. But I checked the spark plugs, they are open. And the PSU did not drop the voltage on the fire if you noticed.

There are no other inputs or outputs to check.

I did similar shuffle with an Abarth Spider SatNav SD card. I bought one with valid preburned identity code, used it to download and install the latest maps, then after two weeks (from the first insertion of the card), once it encrypted the contents to my particular VIN, it allows to create and use backup on any card which I did and then restored the original contents to the original card and sold the it on eBay with 10% off. If it makes sense.

What startles me, is that during fireworks, the fuse did not go.

 

[mainline]

That is a valid concern. But I checked the spark plugs, they are open. And the PSU did not drop the voltage on the fire if you noticed.

There are no other inputs or outputs to check.

I did similar shuffle with an Abarth Spider SatNav SD card. I bought one with valid preburned identity code, used it to download and install the latest maps, then after two weeks (from the first insertion of the card), once it encrypted the contents to my particular VIN, it allows to create and use backup on any card which I did and then restored the original contents to the original card and sold the it on eBay with 10% off. If it makes sense.

What startles me, is that during fireworks, the fuse did not go.

The only reason the voltage on the power supply didn’t alter was that the power supply is obviously well regulated and working as it should.
If you had been monitoring the current it would have been another story.

 

[david74]

The only reason the voltage on the power supply didn’t alter was that the power supply is obviously well regulated and working as it should.
If you had been monitoring the current it would have been another story.

The board supplier says they need two weeks to fulfil the order. In a meantime, I still have the second replacement resistor from the pack. How to determine the capacitor specs to order? How to thwart potential overload to avoid the fireworks if I plug it in which did not require an arm and a leg in sophistication?

 

[mainline]

The board supplier says they need two weeks to fulfil the order. In a meantime, I still have the second replacement resistor from the pack. How to determine the capacitor specs to order? How to thwart potential overload to avoid the fireworks if I plug it in which did not require an arm and a leg in sophistication?

Really speaking you could do with a current limiting power supply.
a decent soldering /desolderer station.
A capacitor tester
Diode/transistor tester
A ring meter.
A circuit diagram
and knowledge and experience.
I would remove the capacitor and the transformer, replace the resistor and try again.

 

[david74]

Really speaking you could do with a current limiting power supply.
a decent soldering /desolderer station.
A capacitor tester
Diode/transistor tester
A ring meter.
A circuit diagram
and knowledge and experience.
I would remove the capacitor and the transformer, replace the resistor and try again.

Thank you, I will try that. But what do you mean by transformer? Forgive my ignorance but is not it called an ignition coil. Well it is a transformer. I hear you. I will try it without resistor first (and without transformer) to see if it opens the valve and come back to you.

Is there an AI that could be supplied with photos and come back with a diagram?

 

[david74]

The LZL-24H is a relay.

Yes I meant the ignition one.

Great. Thank you! BTW, there is a 24V 50A transformer too.

What I did now was to snip a leg of that resistor and without unsoldering the ignition one (but without connecting the spark plugs), I launched it and funny enough it not only opened a valve but it also went into intensive venting mode that it did not start before.

Should I add a video? Anyway here it is.

I did hear a clear click of the valve opening.

And I also understand that relay can potentially be used as a transformer. Or at least as an amplifier. Forgive my ignorance. If I sound daft.

I will hear for your answer before I do anything else because I have hair raised at the moment and need a 12h cooldown in any case.

 

[mainline]

Great. Thank you! BTW, there is a 24V 50A transformer too.

What I did now was to snip a leg of that resistor and without unsoldering the ignition one (but without connecting the spark plugs), I launched it and funny enough it not only opened a valve but it also went into intensive venting mode that it did not start before.

Should I add a video? Anyway here it is.
View attachment 118665

I did hear a clear click of the valve opening.

And I also understand that relay can potentially be used as a transformer. Or at least as an amplifier. Forgive my ignorance. If I sound daft.

I will hear for your answer before I do anything else because I have hair raised at the moment and need a 12h cooldown in any case.

The fault is probably going to be in the igniter circuit.
A relay is used to switch a higher current/voltage from a smaller one in this case it maybe switching the fan/valve or other circuits.
The igniter circuit will be delayed until the fan has cleared any gas and then switch gas to the pilot /ignitor until the sensor knows that the pilot is ignited.

 

[david74]

The fault is probably going to be in the igniter circuit.
A relay is used to switch a higher current/voltage from a smaller one in this case it maybe switching the fan/valve or other circuits.
The igniter circuit will be delayed until the fan has cleared any gas and then switch gas to the pilot /ignitor until the sensor knows that the pilot is ignited.

I have a plan, I will remove the transformer. Remove the igniter. See if igniter does spark. In the process, I'll have the multimeter connected to 24V to see how it behaves.

I will start with 2mm gap and go down to 0.5mm.

But that is all tomorrow if it is not busy as it should be as it has been quiet.