12v 3000w inverter repair help

[Stockleys1]

Hi all. First time post for meI’m after some helpI am trying to repair a high frequency 3000w inverter.It worked great for 3 weeks when I got it (after replacing 2 IGBT’s)But then they blew and many more replacementsI bought a new spwm board from the manufacturer and a complete new set of IGBT’s along with their associated resistors and diode.Installed. And nothing. ABout 10 seconds in and one of the h bridge drivers exploded.So I ordered an EGS002 board from amazon. All pinouts exactly the same. Same chips as the spwm from the manufacturer only a third the price.I have installed this and tested all components around it including the IGBT’s. They are all good.The IGBT’s are getting a steady 390vdc source. The spwm getting a steady 5v and 12vBut I can’t get an output. I can hear the transformers buzz for 3 seconds then stop I get a blip of up to 8vac at the output. The spwm board flashes out the code for under voltage and over voltage. Where do I go from here? I don’t own a scope. Only a ddm. 

I have checked and re check all components and solder joints.  But as I don’t own a scope, I can’t think what else to do.Thanks in advance

 

[HarryA1]

Without a circuit diagram it is very difficult to help you.  You can find numerous videos on youtube.com related to "EGS002 "   that maybe helpful. Good luck.

Looks like I was born under the sign  -V  (I talk to much?)

 

[Stockleys1]

I got myself a usb scope.   

I found that the egs002 wasn’t giving the correct wave.  On outputs 1 and 2.   And output 3 was a constant 6v.  Not a wave at all.    Got another egs002 (before getting the scope). And that had one dead output.

Attatched is a schematic for the egs002.   And the h bridge.  Which although not for my inverter, is identical   

 

[tagjags]

for whoever reads this can be useful,took me a while to figure out

The EGS002  Will ONLY produce waves for more than 3 seconds IF...

1»»»»»  pin 1 (over current)  must see LESS than 0.5 volts DC  (2  blinks of the egs002 led  if not...); 

 15»»»»»  pin  15  (output voltage feedback signal) MUST see between  2.75 to 3.15 Volts DC;   set the little blue pot. to  3.0 Volts to test(3  blinks if over 3.15   OR 4 blinks if under 2.75 V)

  16»»»»  pin  16 (over temp) must see  LESS than 4.3 volts (5 blinks if over 4.3 vdc)

These are the ICs FACTORY values ,and I  confirmed them myself on my own inverter builds

Not ONE youtube channel teaches these things,is it on purpose? i should start my own...

 

[leverperfect]

for whoever reads this can be useful,took me a while to figure out

The EGS002  Will ONLY produce waves for more than 3 seconds IF...

1»»»»»  pin 1 (over current)  must see LESS than 0.5 volts DC  (2  blinks of the egs002 led  if not...); 

 15»»»»»  pin  15  (output voltage feedback signal) MUST see between  2.75 to 3.15 Volts DC;   set the little blue pot. to  3.0 Volts to test(3  blinks if over 3.15   OR 4 blinks if under 2.75 V) basket random

  16»»»»  pin  16 (over temp) must see  LESS than 4.3 volts (5 blinks if over 4.3 vdc)

These are the ICs FACTORY values ,and I  confirmed them myself on my own inverter builds

Not ONE youtube channel teaches these things,is it on purpose? i should start my own...

Many thanks, It's useful for me. 

 

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