Induction hob PCB VESTEL 20fr25 from cooker Rangemaster propl60eibl help needed.

[mariukonie]

Hi. Could anyone with knowledge advise if this pcb in photos can be repaired? I'm willing to spend time and money on it to gain experience however I searched net for schematics and couldn't find so it's impossible to know what are some of burnt components. I can't find any second hand replacement board and new one is out of my budget and it exceeds value of cooker. I'm new to this forum but have had few successful pcb repairs of tv's and cooker pcbs and also made few working circuits for fun. Any help appreciated. Regards.

[stj]

Re: Induction hob PCB VESTEL 20fr25 from cooker Rangemaster propl60eibl help needed.

clean off the soot with a cotton bud and some isopropanol and/or white spirit.
then we can get a better look at what is and isnt burned

[mariukonie]

Re: Induction hob PCB VESTEL 20fr25 from cooker Rangemaster propl60eibl help needed.

Thanks. That's already cleaned with alcohol

[mariukonie]

Re: Induction hob PCB VESTEL 20fr25 from cooker Rangemaster propl60eibl help needed.

I'll try to clean better and post more photos.

[mariukonie]

Re: Induction hob PCB VESTEL 20fr25 from cooker Rangemaster propl60eibl help needed.

Please see photos after cleaning.

[CapLeaker]

Re: Induction hob PCB VESTEL 20fr25 from cooker Rangemaster propl60eibl help needed.

Ouch! That needs some real TLC. You got to get rid of all the carbon (black burnt PCB) rebuild the PCB, rebuild the tracks etc. that may be economically not feasible…

[mariukonie]

Re: Induction hob PCB VESTEL 20fr25 from cooker Rangemaster propl60eibl help needed.

Hi I don't mind doing that if I only had schematics. Does anyone has schematics for this or similar board? Also do you think that square chip with multiple feet next to burnt section could be affected? I don't think I can buy one of these.

[lotas]

Re: Induction hob PCB VESTEL 20fr25 from cooker Rangemaster propl60eibl help needed.

If the processor also got it, then I don’t see the point in repairing, check the processor’s power supply resistance, if it is short or very low, then you will have to look for a new or used board.

[mariukonie]

Re: Induction hob PCB VESTEL 20fr25 from cooker Rangemaster propl60eibl help needed.

Thank you. What would be correct resistance value and what would be low? Regards.

[Miky1987]

HI mariukonie. I have the same board on my bench and can help you. And I would also need your help. Could you please check the markings on U1 (primary controller chip). Mine is too damaged to figure out what it was (unless I go forensic and check the DIE inside the chip since it's exposed ). For fun, I am also attaching a photo of a blast of IC (U1) - U1.pdf .

I've attached some photos that may help you. Please Check U5.pdf for help with troubleshooting your board.

[Miky1987]

Hi, as requested the other side of the board.

[mariukonie]

Thank you Boss. Best regards.

[mariukonie]

Hello. I hope you're well. I need to identify 2 elements near the IGBT in the SOT-23 package marked 1M and B97 (Q33S and Q23S).
Fragment of the hob from the Vestel 20FR25 induction cooker with IGBT 20N135SRA.
Internet search results are inconclusive. Thanks for your help.

[R_J]

The 1M seems to be a (Fairchild) MMBTA13LT1G, the B97 could be a 2SB1197A

[mariukonie]

Thank you. Do you think I can use BC817 and BC807 because they are easier to get hold of?

[Miky1987]

Hi, you cannot use BC807, as its specs are worse than those of 2SB1197A (Apparently, there is some current flowing through the Collector). You could try, but the longevity of the repair is then at risk.
BC817 most probably is an adequate replacement for MMBTA13LT1G (if gain is not important, but you could only confirm this by reverse engineering the circuit around it, or TRY ), see below the spec comparison.

[mariukonie]

Thanks. I'll look for something more powerful.

[mariukonie]

So i replaced everything that looked bad to me and got the board tested but the voltages I get on the secondary are 12 volts, just wanted to ask if this is correct? I thought it should be 18v.

[Miky1987]

Hi. Please upload a picture with marked points, where did you measure, describe what you did in detail. Maybe i can help… I don't have this board anymore, since it was repaired and returned to the customer.