LG LSE4616BD Induction Range - Induction burners do not work

[LGinduction]

Model Number

LSE4616BD

Brand

LG

Age

1-5 years

I have an 18 month old LG LSE4616BD induction range and the induction burners have stopped working. The one warming burner which is not induction still heats. The four other induction burners turn on for ten seconds then shut off; they do not heat. I have replaced the main board in the stove top portion PN: EBR82913601 as there looked to be a burnt spot on the board so I figured that was the issue but that didn't solve the problem. All other features of the range appear to function properly except the induction burners. Any idea what the problem is?

 

[rickgburton]

Apparently it's too new and doesn't come up on any parts sites and I don't have any service info on that model. The induction modules are a PITA to diagnose with a wiring schematic. Without a schematic it can't be done. LG usually puts a thermal fuse and thermostat between the two modules. Check those first.

Somewhere on that machine is an envelope with the tech sheet inside. See if you can find it and post a copy here. If you have a lower drawer look behind it or taped to a side panel.

 

[LGinduction]

The envelope is there for the wiring schematic but it’s torn apart and no paperwork inside unfortunately.

There is a 20A ceramic fuse on each of the two filter boards. Both of these fuses are blown. I’ll get some new fuses and try that but what would have caused the fuses to blow? Is it common for these fuses to blow on induction cook tops?

 

[rickgburton]

Good question. It's not common for the fuses to go out. If you replace the fuses you'll just be repairing a symptom and not the problem.

 

[LGinduction]

Dug into this further and found two out of the four IGBT components on each of the two induction heater boards were bad. The rectifier and other IGBTs tested fine. I'll order some replacement IGBTs and test the stove top then. From what I've been reading it seems to be fairly common for an IGBT to go. Could be due to poor heat dissipation and cooling. They are on a pretty good size heat sink and the fans work though. Here's a link to another thread on this forum with similar issues.

NE599N1PBSR Samsung Range - Left induction burners not working

Hello all, The left two burners stopped working after a large pop. i took apart the top and the fuse is blown on the induction board but i also noticed what looks to be a burn mark on the orange pieces in the top right of the attached photo. Can anyone tell me if that's "normal marks" or...

www.applianceblog.com

I'll report back once I get the new IGBTs in. Here's a photo of one of the boards I'm working with for reference.

 

[rickgburton]

Keep us posted.

 

[LGinduction]

Well the range appears to fully work again. I replaced the IGBTs that tested bad and replaced the blown fuses. I put everything back together with the original stove top main control board and it worked. So it appears it did not need a new control board. As far as I can tell the IGBTs must have overheated and blown/shorted and took out the fuses with it. I've used the range a few times now and it continues to work. When I replaced the IGBTs I put new thermal paste on them to hopefully have better heat transfer to the heat sink they are mounted to.

I purchased the IGBTs from Digikey for around $5 each, I needed 4 and the fuses were only a couple of dollars. The generator boards are around $250 CAD each so quite the savings, just took some time. IGBT part number is IHW40N65R5 made by Infineon.

 

[rickgburton]

What is an IGBT ?

 

[LGinduction]

It stands for Insulated Gate Bipolar Transistor. They are the 4 identical components on the board attached to the heatsink at the top of the photo. The bigger component on the center of the heatsink is the rectifier. The components had to be removed from the board to be tested with a multimeter.

Here's a couple videos showing how to test the IGBT once removed from the board.

Here's a couple videos showing how to test the rectifier once removed from the board.

From my research I found that high frequency, high current pulses drive the coils in induction cooktops. The IGBT is the switch that drives the coil. They generate heat when used and I'm guessing the heat is not dissipated well enough through the heatsink and cooling fans causing them to fail. I assume this to be a common failure for induction cooktops. I would add those to the list of things to check when diagnosing an induction cooktop that doesn't function.

 

[rickgburton]

Thank-you!