Tefal GV8962 Pro Express steam iron - no power

[CapLeaker]

Re: Tefal GV8962 Pro Express steam iron - no power

the first 2 pictures show a 24v relay not a 12v, the 3rd pic the inductor. The inductor should be ok showing 1.8 Ohms.

[beetle1303]

Re: Tefal GV8962 Pro Express steam iron - no power

I moved one of the 2 relays, and here's a findings:
1) The pins (red arrow) reads 1569 ohm
2) I applied 12V, both directions, to these pins thinking it should click, but it does not.
3) The in-circuit relay also reads 1569 ohm, and also does not click when applied 12v to the coil pins.

Is this normal?


Next I removed the inductor L2:
1) I don't have DMM that read inductance, but resistance reads 1.8 ohm.
2) With L2 moved, D3 now reads correctly at 579 ohm in one direction only.

Does this means L2 is bad and shorted?

[beetle1303]

Re: Tefal GV8962 Pro Express steam iron - no power

The value of that fusible resistor will be likely be <10 Ohms.
https://ar.pinterest.com/pin/621848661029499082/

From this picture view - it seems like a 4-band resistor: Brown, ?, Brown, Gold. Brown, Black, Black, Gold gives 10 ohm, unless it's Black, Grey, Black, Gold to give 8 ohm?

[budm]

Re: Tefal GV8962 Pro Express steam iron - no power

The value of that fusible resistor will be likely be <10 Ohms.
https://ar.pinterest.com/pin/621848661029499082/

[beetle1303]

Re: Tefal GV8962 Pro Express steam iron - no power

Yes, that was a very bad idea actually. In this case this resistor is a flame proof (green colour) resistor that is used a fusible resistor. Now you putting is there a 5W resistor, I am not sure if that is actually the only damage it did (blowing that 50V cap).

Yes, valuable lesson learnt, thank you.

[beetle1303]

Re: Tefal GV8962 Pro Express steam iron - no power

Your pic #1 bottom right. TR2 looks like it is damaged a little on the top. What is printed on TR2?

Z0103MA. There is some think there but don't seems to be cracked...

[CapLeaker]

Re: Tefal GV8962 Pro Express steam iron - no power

Yes, using this 5W 100ohm is bad idea.. I have gotten a 2W 100ohm to try out later.

Yes, that was a very bad idea actually. In this case this resistor is a flame proof (green colour) resistor that is used a fusible resistor. Now you putting is there a 5W resistor, I am not sure if that is actually the only damage it did (blowing that 50V cap).

[CapLeaker]

Re: Tefal GV8962 Pro Express steam iron - no power

Sorry, I don't get what you meant..
TR2 reads 846 ohm one way between left and center pins, 793 reversed direction, and open in all other combinations.

Your pic #1 bottom right. TR2 looks like it is damaged a little on the top. What is printed on TR2?

[beetle1303]

Re: Tefal GV8962 Pro Express steam iron - no power

Now about D3, what other bad components would cause the 2 solder points to read, with or without the D3, 30ohm both ways?

[CapLeaker]

Re: Tefal GV8962 Pro Express steam iron - no power

I bought a 1N4007 as replacement but have not soldered it in. I used back the original D3 diode, which was reading 576 off circuit in direction only.

thats good, because the 1n4007 is too slow.

[beetle1303]

Re: Tefal GV8962 Pro Express steam iron - no power

I think other component (the 50v filter cap was blown due to high Voltage dump) that are connected to the buck converter are damaged when you power it up with bad IC, you were dumping over 300VDC into the low Voltage circuit.

Yes, the initial state when I opened up the steam iron, this cap was ok visually, and R1 was burnt. When I replace R1 with a 5W resistor, this cap blown while the 5W resistor survived..

[beetle1303]

Re: Tefal GV8962 Pro Express steam iron - no power

...and that 5w 100ohm resistor replacement that couldnt blow...

Yes, using this 5W 100ohm is bad idea.. I have gotten a 2W 100ohm to try out later.

[beetle1303]

Re: Tefal GV8962 Pro Express steam iron - no power

D3 will not be a 1n4007 diode, it will be a ultra fast switching diode and likely 1Amp, 1kv maybe a UF4007

I bought a 1N4007 as replacement but have not soldered it in. I used back the original D3 diode, which was reading 576 off circuit in direction only.

[beetle1303]

Re: Tefal GV8962 Pro Express steam iron - no power

is there a piece missing off TR2?

Sorry, I don't get what you meant..
TR2 reads 846 ohm one way between left and center pins, 793 reversed direction, and open in all other combinations.

[CapLeaker]

Re: Tefal GV8962 Pro Express steam iron - no power

...and that 5w 100ohm resistor replacement that couldnt blow...

[budm]

Re: Tefal GV8962 Pro Express steam iron - no power

I think other component (the 50v filter cap was blown due to high Voltage dump) that are connected to the buck converter are damaged when you power it up with bad IC, you were dumping over 300VDC into the low Voltage circuit.

[R_J]

Re: Tefal GV8962 Pro Express steam iron - no power

D3 will not be a 1n4007 diode, it will be a ultra fast switching diode and likely 1Amp, 1kv maybe a UF4007

[CapLeaker]

Re: Tefal GV8962 Pro Express steam iron - no power

is there a piece missing off TR2?

[beetle1303]

Re: Tefal GV8962 Pro Express steam iron - no power

I gotten a new LNK304PN, and it reads 5M+ ohm between Drain Pin and each of the 4 Source Pin.
I removed the shorted chip (it reads 28ohm between Drain and Source), and soldered back D3, and it still reads 30 both directions.. I think the circuit is shorted somewhere because it already measured 30 between the 2 solder points before D3 is re-inserted.

[CapLeaker]

Re: Tefal GV8962 Pro Express steam iron - no power

take u1 out and measure d3 again in circuit