Siemens Sinamics Inverter Many Errors Pop-up Repair

Siemens Sinamics Inverter Many Errors Pop-up Repair
Device	Sinamics 6SL3120-2TE15-0AA4, Sinamics 6SL3120-1TE23-0AA3, Sinamics 6SL3120-2TE21-0AA4
Affects part(s)	DC-DC transformer (VAC 5046X005
Needs equipment	multimeter, soldering iron, soldering station
Difficulty	◉◉◉◌ Hard
Type	Soldering, Part replacement

Problem description

This guide concerns most Siemens Sinamics inverters with similar board to Figure 1. The issue happens suddenly and unexpectedly. Many Errors appear (it varies between inverters and which part is faulty)

Main board (figure 1)

Good trafo measurement (figure 2)

Failed trafo measurement (figure 3)

Under the transformer, after soldering the broken wire (figure 4)

Symptoms

• Multiple errors
• Can not clear errors
• Physically good components, no visible damage

Solution

To solve this issue, you need to identify if this guide is for your specific problem first.

Diagnostic Steps

• Open up the inverter
• Check for any physical damage such as blown up IGBT
• If there is any physical damage, this guide is not for you.
• If there is no physical damage, measure all the transformes on the board like in figure 2, if you read near 0 Ohm, it's good measurement, if it is higher or OL (figure 3), then you have a cut off inductor. Proceed to repair steps.
  

Repair Steps

You can just buy and replace the transformer and that will fix the issues. If you can't buy it or it is not available, you can fix it yourself.

The reason those transformers usually fail is not because of too much current but because they're filled with resin and with many cycles of heating up and cooling down the wire outside the resin gets pulled from the resin and it cuts it off (figure 4) you can just solder it again and it will work again.