Fronius Magic wave 2000 Fuzzy failure

[Jan-DIY]

The transistor mentioned some post before seems not right. As I can see it is triple stage but my documets reading double stage (darlington). Anyway already ordered 2 of them to test in circuit. They will mechanical fit but maybe electrical fail. Will see.

 

[Jan-DIY]

After looking around it seemed to be a sanrex Transistor. But not confirmed now. Try to go into the specifications.

 

[Peet]

After looking around it seemed to be a sanrex Transistor. But not confirmed now. Try to go into the specifications.

Thank you Jan. Please let me know when you find correct aleternative IGBT.
Exist some procedure to measure if is this IGBT ok?

 

[Jan-DIY]

It is not an Igbt.
Darlington NPN power transistor.
Not easy to find any informations.

 

[micau]

Hello,

Does anybody know the type of triac/transistor/voltage regulator on the NMW20 power supply board ? (the one on the aluminium cooling block i have circled in red)
Mine has blown off so I can't figure out the type any more.

Thanks for your help.

 

[Mirza]

Hi.
That's a MOSFET IRF830.
The MOSFET driver IC is a UC3844 or AMC3844 in 14-Pin SOIC

 

[Brad93]

Looks like machine has got dusty, then got damp.

Theres a fume members here familiar with these.

@Jan-DIY might be the quickest to reply.

 

[Mirza]

By the way, I have a problem with Magic Wave 2000, also.
No output voltage on TIG or MMA mode (well, precisely output is +0.135V in DC+ mode, in DC- it's -0.135V).
The Vebo (Emitter-Base Voltage) on Darlington transistors is only 1.3V, I doubt that's even enough for switching?
When switching through AC/DC+/DC- on panel, the LED on darlington driver boards is turning on, but never on both boards at the same time.
No errors reported on panel, HF arc ignition works.

 

[Jan-DIY]

Normal behavior.
These darlington transistors are never be switched on at the same time.

Any strange noise when switching to mma?
Secondary diodes already checked?

 

[Mirza]

No strange noises when switching to mma.
Secondary diodes forward voltage is around 0.4V
When I rotate trimmer pot on current measurement transformer/device I do get a slight change of output voltage, if trimmer pot is turned clockwise by 5-6 times the CAL is display on panel, calibration, I assume. Turning it counterclockwise dismisses the CAL error.

 

[Jan-DIY]

DC bus voltage checked?
Primary transistors active on mma?

 

[Mirza]

On this transformer there is no voltage on primary in MMA mode.
On marked connector there is +15VDC, but when plugged in voltage drops to 2.75V, same goes for left board connector.

 

[Jan-DIY]

Have a look at the other side of the machine.
There’s the primary section.
Take care.
High ac and dc voltage behind the cover.

 

[Mirza]

What points should I check?
I've already removed primary side PCB and cleaned all 8 of FR0174 (diodes?) modules and cleaned PCB, there was a lot of dust.

 

[Jan-DIY]

All 4 led on primary board lid on mma?
Dc bus voltage checked?

 

[Mirza]

No, all four LEDs are off, when switching to MMA, they are lit for a fraction of a second and then turned off.
Voltage on diodes are in pairs -63V and +35V, for Vcc on HV400MJ (high current MOSFET driver) see image.

 

[Jan-DIY]

Did you measure DC bus voltage?

 

[boky043]

Hi!
I have Fronius MagicWave Fuzzy 2000. When switched in stick mode strange noise is comming out.
On DC+ and AC there is noise all the time.
On DC- the noise is heard for a short time.
What could be the problem? Please, help me.

 

[Jan-DIY]

Strange noise->secondary rectifiers short.

 

[boky043]

Strange noise->secondary rectifiers short.

Thank you very much, Jan.
Do you have any pictures of secondary rectifiers?