New DRSSTC broken - Help

[MEROVINGO85]

(I don't know if it's the right section for my help request post)

Hello,
i'm Francesco from italy, I want to bring you back what happened to me.
I hope to find a good pious soul willing to enlighten me.

Fascinated by this world, I recently bought a small pre-assembled DRSSTC.
The world of T.C. for play midi music, to get excited and to know, maybe build one myself sooner or later.

Maybe is usually to approach this world ... like this ...
Passionate -> study -> TC construction

Instead i've:
Bought a TC -> passionate -> Study (to solve a problem)


I tell you this because I have only one idea (and I am ashamed of it ) DRSSTC, counting on the fact that before breaking it would have taken time ........ But the law of Murphy affects all, but more fools, and the second test of my Tesla coil (in total 10 min of overall use) crack!!!

In practice, while I was testing the TC with only the toroid (without copper wire on top)
an lightining hit the inside circuit (avoid the strike rail), the fuse burned and it stopped to work.


The card (IGBT?)
turns on lights, also the cooling fan run, but while before I had two LEDs, one Red and one yellow ( the yellow is own of the modulator that was turning it off while i gave power),  now have two red LEDs active ..

As a good Homer, I thought it was just a Fuse problem, changing it and rethinking the procedure I got a new burned fuse ... so the problem is there and it's elsewhere.

Now, I took a look at the various cards / components, looking for something abnormal / burned / unsoldered, but without success, in fact I don't have the slightest idea of ​​having to get my hands on it ... and even a simple multimeter test to measure the circuit integrity or any CT voltage turned on scares me (besides not knowing exactly what to look for).

@Update, after a quick check on the transistor, i've found two burned one.
I've replaced both, now the TC turn it on without burning the fuse but didn't activate though the moduletor.

In clear word, it turn on without any funcion!
And this is where I ask for your help, if anyone is willing to help me .... i know without

I have some photos available that I can post if interest someone.

[Teravolt]

So the good news is that it can be fixed the bad news is that it will take a tecnition and equipment to repair it. what is your skills with elecronics and what kind of equipment do you have. A good tecnition may even be able to perminatly fix it. with an oscilloscpoe you would be able to evaluate it for us to understand where the problem is. I suspect that your pimary section is still not fixed this includes the H-bridge and the drive comonents and your primay capacitors. Do you have pictures of the guts of the unit?

[MEROVINGO85]

So the good news is that it can be fixed the bad news is that it will take a tecnition and equipment to repair it. what is your skills with elecronics and what kind of equipment do you have. A good tecnition may even be able to perminatly fix it. with an oscilloscpoe you would be able to evaluate it for us to understand where the problem is. I suspect that your pimary section is still not fixed this includes the H-bridge and the drive comonents and your primay capacitors. Do you have pictures of the guts of the unit?

Hi 👋
Thanks for the reply, I appreciate.
I want start answering to your two question:
My skill are quite zero.
Also my equipment is a multimeter. Stop 🛑
So the situation is dramatically
I’ve done an error with this purchase, it’s a custom made DRSSTC ( Chinese ) bought for my 34 birthday.
I think the component used, in particular for electronic side, are not properly good.
Anyway, I will post all photo that you require.
I want to know more and if there is no chance to test the component, I will directly replace it!

[Laci]

Hello!

I had a similar failure a week ago. In my case a secondary to primary coil flashover blew two transistors(IGBTs) because I grounded the bottom of the secondary to the wall outlet. Do you have a good grounding?

The overall design of your DRSSTC looks nice to me and if it uses a gate drive transformer(which probably is) there's a high chance that the driver circuit is OK. In this case you should check the IGBTs, TVS diodes, gate diodes and resistors; basically the power electronics. They usually go short circuit when they fail, so a resistance, diode or continuity test is good for this.

For further troubleshooting let us see the internals!

[MEROVINGO85]

Hello!

I had a similar failure a week ago. In my case a secondary to primary coil flashover blew two transistors(IGBTs) because I grounded the bottom of the secondary to the wall outlet. Do you have a good grounding?

The overall design of your DRSSTC looks nice to me and if it uses a gate drive transformer(which probably is) there's a high chance that the driver circuit is OK. In this case you should check the IGBTs, TVS diodes, gate diodes and resistors; basically the power electronics. They usually go short circuit when they fail, so a resistance, diode or continuity test is good for this.

For further troubleshooting let us see the internals!

Thanks for the Hint.
I'll try to put all photo that i can, you have a lot of experience and maybe with only simply look, you can direct me in the right way.
The only thing that i ask you it is to be patient.

[Laci]

Which part of the driver was striked? If it hit the logic circuit on the green PCB, it's gonna be harder to repair without an oscilloscope.

You have a red LED (between the ICs), which probably indicates the 5V and a green LED on the board behind the fiber optic receiver which I think indicates the interrupter signal. If you power the board and connect the interrupter it should blink visibly at low frequency. There's another red LED in front of the relay, which does the precharging, I guess. If that doesn't light up after a few seconds after powering up, you probably have no voltage on the inverter.

Checking the feedback signal's logic circuit isn't that easy for you without a function generator. Otherwise it requires feedback signal which you get only if everything is working.

[MEROVINGO85]

Which part of the driver was striked? If it hit the logic circuit on the green PCB, it's gonna be harder to repair without an oscilloscope.

You have a red LED (between the ICs), which probably indicates the 5V and a green LED on the board behind the fiber optic receiver which I think indicates the interrupter signal. If you power the board and connect the interrupter it should blink visibly at low frequency. There's another red LED in front of the relay, which does the precharging, I guess. If that doesn't light up after a few seconds after powering up, you probably have no voltage on the inverter.

Checking the feedback signal's logic circuit isn't that easy for you without a function generator. Otherwise it requires feedback signal which you get only if everything is working.

OK, i've added some new photos.
The one with red oval is where the driver was striked.


Regarding the Oscilloscope and Function Generator, i don't have the minimal idea how to use they...
But if something will guide me.. maybe yes.

The only thing is that a will buy a cheap one...
this are usefull for my scope?
Osc:
https://www.ebay.it/itm/DSO138-2-4-TFT-Kit-di-saldatura-delloscilloscopio-digitale-Guscio-acrilico/401728939133?hash=item5d88e9247d&enc=AQADAAAC8FjVrDbVsZ8oH%2F8PNHtt9VX4%2Fw7FZcmMuqsX8uaFEduVpmydk3aDb29p%2F%2FzZzizxDArb7TQA5fGzkVyRzBVCvbsnk1%2BS3f2YDUAyz771guZrWPoHqKnzG9amWCKJs9jexx%2FvoO%2FikEH33HDnnnZFxVjfV%2BosDzGKEywoLhiC%2BQbzqG7lAuQEwcOGYQ1Xs8m1jQeIirlrLFCyG8YY%2FNGre1MGYoJMXXGTHLIKBf4IViu09w1VvZSqW44%2BF7L7bzRS9mx5nKE0Y0qZY%2FwP9XfnnOlqRvI6VqIDCUApaOxQ%2Bp9JpffpNVzEsQNo4vDWBqGwuTjJMdkUdxIMKjkyO0%2F%2BIeYE3Xg7VreghzjJqRzBqNyH82IH4tp7nGUD1jCV9lvd4H2IwkLmCWJJp4msuseIN8Rrb6DbkMrwsym5FL6EHMKQsvg59LUamcNQt6D18SuDLo1YIli8YBDklUsVW1vXMFg5oX%2FD6rn2idnQroStGI%2BPn8wme4BpLWzfjVOzpemDwgGCiIpNREWB%2BJiSwDF8wqg705XI2snc1tnl1NEyAGiWgTvfwQVhiPIoGmop94mOO1bwY7zy04UedO2wYDZC18GgHxwl2NUSQJEx81h5OYzB7IfDipogO7UjKNb1mkWpMvC1zCM226CswDPY4qWipS%2BgvwMLnDjdRcq1Af42dgftytK0sXtpeZHeTJgB76tCX%2BBGTSF3pOJsfPSIETXp7BAlsodPfTrHlADr6ZHpxfM%2FKebzvUltV3nfDI%2FcDJEy%2Bz%2BrUlv0t2XOhEEGok3yH12c1VaL7WwDX1GrySF0vs7S0CGAYpM%2FvCotDuQ0vcyNOhvS7172ddYtraGsxo6vfQYUqXTTmzlJpWjAWGoS5h%2Bq0%2FqiuHVm7Qc%2BP%2BXI2zwNgSsQQ%2BDrOD4NdYG45h1ceAip9G2j8NSU2DE%2F%2FOnxw7CrRnJ6U8dRqhfLI24l6utVvhQPHK2ZuhIomOhNoC94Ts%2FzANMCYSys0NdL8kA5qAfc&checksum=4017289391331f22eb20670b487694d11a243cf3ba78

FG:
https://www.ebay.it/itm/Signal-DDS-FG-100-Generatore-di-funzioni-con-connettore-dati-USB-1Hz-500kHz/173366049767?hash=item285d6bfbe7&enc=AQADAAADAFjVrDbVsZ8oH%2F8PNHtt9VX4%2Fw7FZcmMuqsX8uaFEduVVT99FZjcJSUey6JHlj%2Fo1z%2Bey3ZgStVf5rtUgjb2bN9AmPng870jt618AsxC9V8f5Wln675TwydcFZJcYbE37na3ZsQi4Di1ez4eZu4X%2Fsk2SNDR0961bUNXlzrwMS6Qqfxr41VkPlr4dOcc31CdPKuRgGQN4ZKb7i3A7uKxCiFlHVP05u5g5SIZxRdfw20iE14vz%2BIll2E%2B6XqhoSKRXVW9z%2Bx9dJ2sDjUxnFScCyMKbMSCdZffFQdui%2BkC8pWebODHmMOrE2OwhWvE7tV5JrFRNAsl6DcdiX7EdfyU37%2FprMCG5bC6oKv60gFeLetLHnfpYMOxxi16A28nuzl%2BQnNZEuL7V3a3fdxIeVvvUAx4IFM3VZCg6Ea%2BOx%2FL5rVG07QM98aELz1sp%2BPuqOUnEzOMolk%2BWiOwaj2332nygCmJSk98SvcNW40CGqZPzJLN73uppT3apQwn8TbF5plH4F%2B3tiFwIv%2F2Kf6KDYlulW1XLXrtliMebneYk4PFzbA9A7ot6L0n5rjDsAXbcdQzd9hzPYH5rb7gTfLHzt7Nx10IlhhEA8k9Cl9Ffhox7yVnorbn7IBZUfqI54OolT4aBcmjQ%2F3cyE2peYLPiGS4CutHt5XlgCRMDnVfSWhP93a%2B7Uax9LAMw7%2FTg7vCXvGdGT5rvG%2Ff931Hr3e61XXLdiUCA9CEmBJu4kPud4faks%2BCTYZraaEebhQ5P%2Bx78hNe4HDM6joQfv0eWQ7saXOTpF1%2FQyviLj3kBHzdff1EC%2BABVF5ypw24Ei6WKX7lLaKwxihFALz7A8RKy6GuODmd7Uq4B%2FSWkQzMoyHZGr4AgOpsif68NK7KIyCbSGZYqHktwt4nKmt%2BOlav9q9%2BiLUDtmACbUrfep0uZOyOaMX8x%2FTEEg4oL4V2Y7jN8qf6fki%2B%2FDG%2B%2FdAw%2B3%2FCdlmdpjMfHym%2F17l2lNT%2F1FCoC%2FljrZfzVK1Dr2AYkr3LpEwYQdHgfQ%3D%3D&checksum=173366049767111d0f7bf6654ff49d9570429b702c1c

Thanks

[Teravolt]

I think it is worth fixing. there has been many discussions about cheep chines mosfets and just replacing them may be an issue because even though the fets have the same number and logos printed on them the actual die in the device is different. The image that I have picked has 2  what looks like mosfets and a bunch of diodes surrounding the devices. have you used your multimeter in the diode mode to verify that none are shorted specially the transorbs next to the red wire. Does the tesla have 2 or 4 fets, these are the bridge fets that convert the rectified line voltage. this will be the dangerous part of the tesla and if you are not comfortable probing this you will need someone that is. The object is to determine if your mains rectifiers are good and that you have your mains dc filtered voltage present. It looks like a full wave doubler is your voltage source to the tune of plus and minus 311Vdc at your line voltage. Because you have about 622Vdc your fets will have to be 1200v. this may be the problem why it died. What is the number printed on your fets? I would try something like

https://www.ebay.it/itm/ON-Semiconductor-NGTB40N120L3WG-IGBT-160-A-1200-V-3-Pin-TO-247/163124118740?hash=item25faf484d4:g:f1MAAOSw5ItbNloq

or

https://www.ebay.it/itm/1-pc-IXYH82N120C3-IXYS-IGBT-1200V-200A-1250W-TO247AD-NEW-BP/232735336094?hash=item36301b669e:g:MFAAAOSwq7JT3ARH

I go by max power rating at 1200v. Italian EBAY is kind of the wild west because I don't see pictures of what you re getting and some of these parts are from Germany. hopefully more will chime in hear to help you. Do you have all of your power voltages on your driver board like the 5v 12v 24v ect.

[Mads Barnkob]

It ain't easy trying to repair electronics without knowledge and tools, but cudos for coming here and ask how to go about, learn some more and fix it!

The DSO138 is a max. 200 kHz "for fun" scope, it has its moments of use but overall it is just a gadget, not a tool, when it comes to working on high frequency circuits like this. The size of your coil suggest it is in the range of 300 kHz, so a 200 kHz scope will not do you any good due to Nyquist sampling theorem, you are simply not sure that what you see on the scope is actually what happens in the circuit ( for interest see: https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem )

The function generator is however fine enough, but you need at-least a 1MHz scope, even a old analogue 10 MHz will do you real good, that is what I started out with

So your board does light up, yellow and red LEDs. What does these indicate according to your manual?

Did you check all board voltages at the different ICs? Use a multimeter and check at the power input pins for each IC according to their datasheets.

When checking out IGBTs, TVS diodes, gate resistors etc. you really have to unsolder them in order to be sure what you are measuring, it could just be a while other path in the gate drive circuit you see than the single components. At IGBT failures I have often seen TVS diodes and gate resistors die as-well or get damaged to an extend where proper operation is no longer present.

[MEROVINGO85]

Hi buddy,
sorry for the delayed answer, this days i was looking around for find someone that help me.
Anyway i’ve found a “friend”  with all tools necessary!!
I will update ASAP when the problem will be found.
I prefer for this time accept an external help.
https://ibb.co/vmZFnC6

Thanks

[Netzpfuscher]

by the way, it's not a good thing to place the feedback current transformer behind the resonance capacitor. At this point you have a very high voltage to ground. The transformer should be placed directly behind the inverter.

[MEROVINGO85]

It ain't easy trying to repair electronics without knowledge and tools, but cudos for coming here and ask how to go about, learn some more and fix it!

The DSO138 is a max. 200 kHz "for fun" scope, it has its moments of use but overall it is just a gadget, not a tool, when it comes to working on high frequency circuits like this. The size of your coil suggest it is in the range of 300 kHz, so a 200 kHz scope will not do you any good due to Nyquist sampling theorem, you are simply not sure that what you see on the scope is actually what happens in the circuit ( for interest see: https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem )

The function generator is however fine enough, but you need at-least a 1MHz scope, even a old analogue 10 MHz will do you real good, that is what I started out with

So your board does light up, yellow and red LEDs. What does these indicate according to your manual?
Unfortunately i don't have any datasheets so I don't know what the led lights indicate .

Did you check all board voltages at the different ICs?
Use a multimeter and check at the power input pins for each IC according to their datasheets.

This is a very good way to do a first check.. for do this i need to switch on the TC and am i little bit scared.
I prefer to wait the respons of my friend, in addition the repair, he will offer to me a quick lesson abought this kind of circuit.


When checking out IGBTs, TVS diodes, gate resistors etc. you really have to unsolder them in order to be sure what you are measuring, it could just be a while other path in the gate drive circuit you see than the single components. At IGBT failures I have often seen TVS diodes and gate resistors die as-well or get damaged to an extend where proper operation is no longer present.

[MEROVINGO85]

by the way, it's not a good thing to place the feedback current transformer behind the resonance capacitor. At this point you have a very high voltage to ground. The transformer should be placed directly behind the inverter.

Great Netzpfuscher,
i saw your videos on threed "Next Gen DRSSTC" and i think you are one of the best TC builder seen till now.
Anyway, apologize for my incompetence.
Based on the previous photos reported, could you please draw me a draft  model of the sentence above?

[Teravolt]

Its good that you found a friend to help you just remember to use some sort of isolation transformer if measuring the primary circuitry while measuring. it can be dangerous with out the respect of the 220vac where you live. let us know of your progress and if you or your friend want to ask questions I am shure somebody will help.