Problem: Error codes 26 or 42 after turning on too many heating elements.

Potential issue: Damaged electronic board

Specific case: Error code 42 after turning on more than 3 elements, then already after 2, 1 until none of the cooking element could be turned on, over a period of a few weeks.

Root cause: Dying/blown electrolytic capacitor on the main electronics board.

Solution:

  1. Turn off power (circuit breaker) - caution high voltage inside the cooktop
  2. Lift the cooktop out of the hole in the countertop and slide it on a flat surface
  3. Remove all screws around the metal housing using a torx screwdriver
  4. Carefully tilt the glass top out of the housing on the front, noting that there are electrical connections in the rear, and place the rear end of the glass on a stable surface. You may need someone's assistance here.
  5. After double-checking that there is no power, record the color coding of the four wires connected to the glass assembly (green for ground, white, black, red from left to right)
  6. Next open the black plastic cover by removing four Torx screws.
  7. Carefully remove from the connector on the left the the plastic strip connecting to the display board.
  8. Carefully remove the circuit board with relays and capacitors that is held in place by plastic tabs.
  9. If one of the capacitors is bulging out or showing sings of damage on top, replacing it may fix the appliance. De-soldering a bad capacitor requires some tools and skill. Replace the capacitor with at least the same capacity, voltage and use high-temp. 105C version) Alternatively, instead of replacing a $2 component you will have to replace the entire board.
  10. Reassemble and done.
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16 Comments

Great fix. Fixed my cooktop for $4 in parts plus $12 for the soldering iron.

My same model cooktop showed similar symptoms, except like Capt Kirk fading from one universe to the next, it appears my (flux) capacitors were fading in and out of the working universe. Both my 470 microF capacitors were bulged and very slightly leaked.

Circuit board work is not my strong suit - I can sweat pipe, but those tiny connections with heat sensitive components are hard. Nevertheless I managed to get the old ones out and put two new ones in.

I'm not sure who I'm thanking, but Thanks!

Richard Skeirik - Reply

Being the unknowing person that I am where did you find the caps? bonitajay@comcast.net

Jay Wilker -

Really appreciate the tip. Ordered 2 caps (even though only one was bulging, I replaced both) of same dimensions. Replacements came and were 5MM shorter than represented, but same specs so hope they work for the long term. The replacement complete circuit board module is about $400 I was told. Thanks again - am now going to do the same with a motherboard in my tower that failed with 4 fat caps!

J. Walters

jim walters - Reply

Excellent advice, worked out perfectly. I changed all the electrolytics on the board, took a while to source the parts (due to the clearances required) but figured they will all split sometime down the road. Had to settle for the 105C components but hopefully they will work out.

Thanks again.

Happy cooking!

Les - Reply

Thank you so much!!! Appliance store said nothing they could do to fix cook top. So, we were ready to replace circuit board for ($ 500.00) or buy new cook top ($ 1,000.00) when we decided to try to replace the capacitors. We couldn't find the parts (capacitors) locally so we order them on Amazon. So far so good worked perfectly! Again thank you so much!

:) Happy Cook!!!!

Dee - Reply

This worked for me. It took a while to get the two caps unsoldered from the of board, but this was a very helpful walk through. One point that was a bit glossed over: after noting color codes of the four power leads, disconnecting them makes it much easier to lay the top flat. Thanks for the detailed breakdown. Saved us a $500 board replacement service call.

dakotakid - Reply

Anyone has any issue after replacing the caps? I tried to fix and gotten the cooktop to work, but after a few days of "normal" operation, the cooktop stop working. Now when pressing the START, there is no light come up at all. The unit is not powering up. Anyone has any idea about what might be the issue? Do I need to get a service call to repair the cooktop?

paulwchau -

Thanks so much for posting this fix! I just got through it on a similar model (Bosch NET9652UC), replacing the 25V capacitors with 35V as suggested on another site. Both of my 470 microF capacitors had bulged and slightly leaked, and so I'm hoping this will solve the problem. Our cooktop had started giving us "Err 42" any time it was colder than about 68 degrees F in the house. One part of the fix that wasn't obvious to me when working on it was in step 7 above: removing the tape-like plastic strip of wires connecting to the display board. I thought I had to pull the black box at the end of the plastic strip off of the board to disconnect it, but actually the strip itself comes out of the box -- the box is permanently attached to the board. So don't try too hard to pull it off! Seems to me that this problem with the capacitors is a basic design flaw in their cooktops and they should have recalled them or should fix them for free. I wonder if the replacement boards they sell have different capacitors.

EcoProf - Reply

Hi, how did the 35 v vs the 25v work out for your cooktop. We also have the 9652uc with the same problem.

Thanks! Al

Sandra Millward -

Eco Prof or anyone who used the: 470uF, 35v, 105c cap, how is it working from perspective of time? I know it allows more voltage to go to the mother board, did it fry anything over the years? Maybe it will fry the mother board or the breakers at some point? I just don't want to wait for the 25v for 2 months and was able to get 35v today in stock at Radio Shack. Had to visit 2 of them because there was one at each store. I would hate to see one day my house on fire because of the stupid cap that I bought... Please give me some feedback from someone who used the 35v in place of 25v.

All the best.

stanislaw.rey -

The "35v" caps, that I chose to install (Panasonic) continue to perform excellently ... NO issues at all with HEAVY USE! When picking a replacement it is important to carefully CONSIDER the overall dimension/SIZE of the replacement caps, available replacement space is limited (read "MASSIVE THANK YOU" (in this fixit thread). Also in my review I list two different "replacement" caps that I found readily available ... Both with much higher heat tolerances ... Their "heat tolerance" is a very important consideration, particularly when the cooktop is located above an oven ... The heat typically shortens the life of the Aluminum Electrolytic Capacitors .... So check the overall dimensional size of your replacement caps against the "maximum" available space listed in my previous review, to insure the cap will fit without being too tight (squashed into the PCB). NOTE: original cap was by SAMWHA ( 'original' spec-sheet in my prior review), Look at: www.badcaps.org a education on cap-failure.

Dennis in Cupertino CA -

A huge thanks for this post. I was able to buy two replacement capacitors from Amazon for $3.50 each. Item link: http://amzn.com/B0195UVHCA I'm pretty handy with a soldering iron, so the actual fix was pretty quick once I gained access to the system board.

Scott Savett - Reply

MASSIVE THANK YOU !

ER42

Fnd 2 blown Caps as in photo

OEM Bosch Cap:

SAMWHA WM

470 uF

V 25

105 C

10mm x 16mm

Google: https://encrypted.google.com/url?sa=t&rc...

Max Cap size avail for replacements: 12.5 mm x 21.5 mm.

I used Nichicon VZ(M) Series, 470uF, 35v, 105c www.digikey.com ; possible rpl fit - Panasonic TP Series 470uF, 35v, 125c, 12.5mm x 20.55 mm.

-Enclosure TORX #20;

-Soldering temp 760-770 F;

* Big help: “micro-drills” for PCB $3 / Amazon Ebay; bits cleared solder in holes:

http://www.ebay.com/itm/10-Pcs-0-3mm-to-...

DENNIS F.

Dennis in Cupertino CA - Reply

The error 42 would show intermittently. I replaced the two capacitors and now works GREAT. Many thanks for the $6.78 fix (amazon took a few weeks to receive.... slow boat from China) . I was able to remove and replace without issue, just flipped the breaker off, lifted out and flipped over, no need to disconnect. The whole job took 20 minutes in total and I don't have too steady a hand nor the greatest eyes LOL. I recommend the fix it was well worth it. Many thanks for the input.

Ken K - Reply

Another success story! I replaced the two bad capacitors and it works. Fantastic! Thank you!

Ted Parker - Reply

After following this thread for over a year, I had to finally do something as the spastic ER42 was coming up at supper time. I was at the point where I'd turn off the breaker, wait 10 sec and then when I'd turn it back on my wife would immediately turn on an element...

Although a successful repair, it's not as easy as it seems for someone that's not familiar with soldering (ie. me). I suggest you take some time to google common soldering procedures and remember to be patient.

As for purchasing the capacitors, I searched locally (I'm in Montreal, QC, Canada) and found a little store that carries all these things for $0.50 or less...crazy cool find and actually spent some time looking up some other gadgets (https://abra-electronics.com/).

Garrett

Montreal, Canada

Garrett Austin - Reply

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