Here are some schematics that I reverse engineered from Anern Victor Max 10.2kW inverter. Should be very similar to Axpert VM models. Of course, part references and connector pinouts are different. Also ADC and GPIO assignments do not match genuine Voltronic's.

The SCC board schematic is complete - PV boost circuit, voltage and current measurement, AC power supply and bus soft start circuit.

Then there's a schematic of the two power supplies on the main board - this inverter uses an auxillary 150V power supply to start from the battery.

Also a I attempted to trace the analog part of the control/DSP board. This was little bit harder as there were no printed part references on the board. But all op-amps are there, nothing important (for understanding the circuit function) should be missing. [15/Aug/2025 added the remaining "digital" part]

I think there will be some errors, so every feedback is appreciated. I can provide KiCad project files if anyone is interested.

Edited August 24, 2025Aug 24 by kuba.cz

Outstanding job. Appreciate your efforts

Can you add DSP Board 2/2 Drawing also

Not yet. I'm still at the very beginning of drawing part 2/2, hopefully I'll be able to finish it later this year. But I do have the board on hand so I can provide some part values/pinouts if needed.

Looking forward for your drawings. In mean while can you share high resolution pictures of Main Board, MPPT Card and Controller card, either in full or in parts. Both sides of PCB's. Thanks

Here are some photos. Not great but I tried my best.

To avoid confusion, I have to note that I've made some modifications on the main board. I have three of these boards (got them as not-working) and all of them had signs of arcing around the drain of Q71 or TX9's primary winding. On this particular one, U10 and R255 was faulty. There were some unsuccessul repair attempts from the previous owner.

After replacing the parts (including Q71 which still measured OK), I decided to also remove R249/D64 and install the unpopulated RCD clamp to reduce the voltage spikes. Used 3.3nF capacitor for C143, 150k/3W resistor for R245 and some diode that I don't remember. That didn't work out, the same parts blew again after a few power ons (exactly when the soft start turned off and SPS_IN raised to the bus voltage). BUT most likely due to my mistake that I didn't check R253 which was already open-circuit. Wrongly suspecting the RCD clamp's diode to be too slow, I deciced to try an RC snubber instead, consisting of a 100pF/3kV MLCC capacitor and 33R/5W resistor, connected between source and drain of Q71. Only then, watching the waveforms on the oscilloscope, I realized that the duty cycle is constant 50% and the power supply keeps switching off and on by the optocoupler feedback. That lead me to the R253 1k resistor. After replacing it, everything works fine and the waveform on the drain of Q71 looks nice so I left the RC snubber there, not trying to revert to the RCD clamp. So that's the current state of the main board on the photo.

Also I swapped the DSP, the orignal one was TMS320F28062PZT, this one is TMS320F28066PZT (differs in memory size), but this is only related to my experiments, not a malfunction of the inverter.

Hello... I'm repairing a 10.2kW inverter. Can someone help me find the transistor series for Q1, Q2, Q16, and Q40 with the code "RAAHDGG"?

I'm having a hard time replacing these parts because they're shorted and i dont know what the code of transistor.

Thank you in advance.

Q1, Q2, Q16, and Q40 short

I've added schematic part 2/2 of the DSP board to the first post in this topic, hopefully it's complete now.

Also I made some minor changes in part 1/2. Most importantly, R85 and R86 values in the inverter DC offset measurement circuit were wrong (10k), these are 1k resistors.

Thanks for providing part 2 of DSP drawing. Appreciate your efforts.

Can anyone advise the size of resistor marked R255 to mine has burnt.

Hello Dear Friends,

any one have firmware Anren pv7200

great great work there! thank you for sharing!

I have one inverter that is dead, no power on - I suspect something burned on auxiliary power supply.

On 2025/10/02 at 2:51 PM, RickH said:

Can anyone advise the size of resistor marked R255 to mine has burnt.

It's in the schematic, 0R5, like 0.5 Ohms. 5W rating is just a guess, it's probably less, maybe 3W. You can also use two 1 Ohm resistors in parallel.

If it's burnt, you need to check other components as well. Especially Q71, U10, R253, R250, R249, D49. You may also want to add an RC snubber or RCD clamp to prevent the same failure happening again (see my earlier post - the one with board photos).

On 2025/10/07 at 2:05 PM, shakeel ahmad said:

Hello Dear Friends,

any one have firmware Anren pv7200

I only have firmware for two different 10.2kW models (single MPPT and dual MPPT).

On 2025/10/11 at 12:25 PM, kuba.cz said:

I only have firmware for two different 10.2kW models (single MPPT and dual MPPT).

ok sir can you shear with me both firmware and what is procedure to install in inverter.

Hi. A year ago, I bought one of these Hybrid inverters (Victor Max-10.2 KW). No other branding marks available.

It was intended for a wide beam boat that was being built at the time. So, after being unopened till last week, when I decided to install it. I was disappointed to discover on power up that an error code (57 Current sensor failed) appeared along with the battery and AC icon. as its out of warranty, and as it came from AliExpress, (no joy with them). I wondered if you could shed some light on what components would be causing the error?

Your in-depth knowledge and skills that you have demonstrated in re-mapping this type of inverter is impressive, I commend you for taking the time to publish the diagrams on the forum. Thank you.

Hi! I have a similar 10.2 kW inverter. NCEP15T14 field effect transistors - 20 pcs burned out. Can you tell me which more powerful transistors can be replaced with?

is it safe to run the Main power supply without the RCD Snubber circuit? i got one inverter with failed UC3845... but the Q71 mosfet is not damaged. this is the first design that i see without RCD Snubber. Is this cost saving or something else?

On 2025/11/11 at 1:42 AM, sethmad said:

is it safe to run the Main power supply without the RCD Snubber circuit?

This is not my area of expertise. But my guess is no, it's not safe in the long run; this seems like the worst kind of penny pinching to me.

On 2025/11/10 at 4:42 PM, sethmad said:

Is this cost saving or something else?

I'm not sure what was the reason to remove the snubber, but the power supply seems to run fine without it as long as the output current stays within normal range. But when there's a short circuit (and that can be on the COM port also), the voltage spikes can be high enough to cause arcing on the transistor drain or transformer pins.

If UC3845 failed, don't forget to check R253. The power supply may run even if this resistor is open-circuit, but UC3845 will stay at 50% duty cycle, just switching on and off according to the voltage feedback. In this mode, the spikes on the primary will be extremely high.

Currently I'm running two inverters with RC snubber added between source and drain of the MOSFET without any issues (that's not an RCD clamp as show in the schematic). I used 100pF/3kV MLCC capacitor and 33R/5W resistor as already mentioned.

Some more schematics here. These are from Easun SMW 8kW which is, I believe, identical to Axpert Max 8kW. In this case the control board did have part references printed so most of those in the schematic should be correct. It's a multilayer board but only power planes are on the inside layers so it's not that hard to trace. The main difference, compared to Anern, is that this board uses multiplexers for 8 of the ADC's inputs, increasing total number of available analog inputs to 24.

I also made a schematic of the SCR board and some fragments of the main board.

I'm not going to make schematics of any power supplies as these are already pretty obvious. Just note that the topology in this case is different from Anern's. There's no intermediate SPS_IN (150V+) branch. The main power supply and bus softstart are located on the main board and powered directly by the battery voltage through a diode. The grid/AC power supply and solar power supply are on a separate board, both of these output around 63-66V and also provide power to the main power supply through diodes. Unlike Anern's, this topology does not need a relay in the softstart circuit.

I made a note of some critical parts (MOSFET type, shunt resistor value and how they deal with voltage spikes):

• main SPS: JCS86N25WT, 0.15R, RC snubber 2x47R (parallel), 2.2nF

• softstart: SIF13N50C, 0.62R, RC snubber 2x22R (parallel), 220pF

• grid SPS: SVF9N90F, 0.47R, RCD clamp 15k/5W, 10nF

• solar SPS: SVF9N90F, 0.47R, RCD clamp 15k/5W, 10nF

Original KiCad files and PDF schematics are available on my GitHub: https://github.com/solar-pwr/axpert/

There will be errors as usual, so every feedback is appreciated.

On 10/11/2025 at 4:25 AM, kuba.cz said:

I only have firmware for two different 10.2kW models (single MPPT and dual MPPT).

My inverter is the one in the photo; I also sent you a picture of its firmware. It has a problem: it keeps disconnecting the MPPT and going to 90V, especially when clouds pass in front of the sun. Do you have a newer version that could correct this error?

This looks similar to Anern. Both Anerns that I have are not user-updateable. They don't have a bootloader so they can't be updated through the serial port. It could be possible to replace the DSP on the control board with a new (unlocked) one and flash the firmware using JTAG, but unfortunately I don't have any firmware for this particular model.