Very useful information for anyone not familiar wthe the issues and pitfalls of repairing invertor types of microwave. Michael is a goldmine of information.
A number of factors are involved here but the biggest one was the plastic they used contained contaminants which leached into the IGBT die and changed the characteristics of the device over time.
I started repairing microwave ovens in the early 1980s and got out of it just as the inverter ovens came on the market. With the fake parts, not all of them have sanded surfaces. When semiconductor manufacturers reject parts that don't meet specification, they divert them into a bin and these get sold off as scrap. They are diverted before the markings are applied so they look new and genuine, just with nothing printed on them. Unscrupulous dealers buy these parts and print whatever numbers on them they want so you think you are getting the real deal but in reality the device could be anything.
@@michaeldranfield7140 It's not a big deal in the scheme of things. I find I often have to substitute a different package type when replacing some transistors these days as the original parts are long since obsolete. Certainly a small price to pay to get a reliable repair.
I just had a same case with a Siemens HF17566 where the bulb caused a short and took the whole control board... Just for fun I replaced it with an Arduino reprogramming all the features. It was fun! 😀 Now the main (bigger) IGBT went shorted, hopefully a replacement for a stronger type will be enough for years... 😅
16:40 @MikesElectricStuff covered this way back in 2017, which prompted me to do an insulation modification. Of course, the lamp hasn't blown since, but .... peace of mind!
Back in 2017 the micro controller was still available as a spare part so not doing the mod just meant a repair for another day, however the chip is now no longer available so the mod is essential.
Could you do a follow up of WHY that missing earth turns the microwave into a useless metal box? Intriguing. Love your videos and your knowledge Michael. Thanks for your help!
You could take out the bulb but then you won't see your food cooking but you could swap the bulb for a led type if you don't want to fit a plastic sheet. You can buy led microwave now.
New prices of these boards and genuine Panasonic magnatrons have risen so much in recent months it makes the job not worth repairing, prices have risen significantly pdcause parts are becoming obsolete .
@michaeldranfield7140 yes I know I work on alot of domestic appliances and used to deal with "emw" for reconditioned timer boards but they've gone bust and back in the 90s I dealt with that mw spares company . Would you be available to post control boards to for recon?
Yes, this happened just the same when Sharp released the Cs chassis TV and we were told it was bacsuse Sharp wanted to build up a history of the problems to aid future development so I guess it was the same with Panasonic.
Thanks for this, I'm going to fit that plastic sheet between the boards on my Neff, do you just push it up between or did you have to remove the top board?
the last magnetron I had from magsells kept overheating and logging fault codes, bounced twice, could never get it to do it in the workshop. It had alot less fins than the original
I have only ever had a faulty one from Magsells and they just swapped it for me , they tell me there's only 2 or 3 places in the world manufacturing magnetrons
I've had a few brand new Panasonic Inverter microwaves apart recently and I was surpised to see the magnatrons used in them now have Panasonic part numbers and the same style labels but they do not have Panasonic written on them anywhere! Just the part number and made in China. So if you see new magnetrons for sale that have the Panasonic style label and just a part number then there is a chance it could actually be genuine. I've also noticed the quality on these more recent Panasonic microwaves are awful, especially the slimline combo's. I've never seen sheet metal so thin and the convection fan runs off a square rubber band and pulley, these often make an odd noise and can be fixed by bending the stupidly thin brackets so both pulleys are inline, otherwise the belt twists and also flaps all over the place. The smaller non-inverter Panasonic microwaves seem to be manufactured Galanz.
Hello Michael, A bit off topic but could you make a video explaining how to match up a mosfet with an equivalent. Its always been a hassle for me to ensure that the part i am installing is the right replacement. Talk about Rds(on), Vgs, Id, etc. As an example i have a FQPF5N50C and want to replace it with a STP9N60M2. The specifications on the replacement are better but the Rds(on) differs a lot. Can you help?
Panasonic don't publish the whole schematic of the board and the diagram I have was found on the Internet over a year ago but I suspect is was copied out of the back of a microwave service manual
Igbt substitution is a bit involved, it's not only about rated current etc, since there are several generations now, with differences in hard switching capabilities, gate capacitances, dI/dT acceptance vs external gate resistor, avalanche ratings, and other factors like presence or not of integrated antiparallel diode and driving requirements and temp derating characteristics. Cheap circuits don't use good driving schemes and often fry the gate with OV and that leads to immediate destruction. Good luck on this...
18:46 I saw someone on YT repair a magnetron. There are two caps under the cover. One or both will ? short ? (if I remember correctly) maybe open . They are in parallel with a low resistance coil, so it is hard to measure them in circuit. I believe the only other way magnetrons fail is when their heating element opens. I don't think I have seen any one replace the heating element. I would probably only attempt the cap replacement in a tight pinch or emergency.
The two RFI caps are within the filliment terminals and not separate but as you say they sometimes go leakey to earth and it's just a matter of replacing the terminal itself.
Fake parts is a real problem now days . I am constantly pi$$ed off over parts sold as oem trying to repair stuff. Cheers from Australia.
Seems like most stuff you buy now is fake unless your buying direct from the manifacture.
Very useful information for anyone not familiar wthe the issues and pitfalls
of repairing invertor types of microwave.
Michael is a goldmine of information.
Many thanks for that.
A number of factors are involved here but the biggest one was the plastic they used contained contaminants which leached into the IGBT die and changed the characteristics of the device over time.
Great video Michael thanks for the information and for the substitute part !
I started repairing microwave ovens in the early 1980s and got out of it just as the inverter ovens came on the market.
With the fake parts, not all of them have sanded surfaces. When semiconductor manufacturers reject parts that don't meet specification, they divert them into a bin and these get sold off as scrap. They are diverted before the markings are applied so they look new and genuine, just with nothing printed on them. Unscrupulous dealers buy these parts and print whatever numbers on them they want so you think you are getting the real deal but in reality the device could be anything.
Absolutely correct and these are the hardest fakes to spot , I had one of these about a year ago and when tested it was just a double diode .
Thank you for sharing your extensive knowledge !
Nice choice of substitute IGBT, it's quite a beast.
And nearley 12 months on proved reliable, just a pity about the different package.
@@michaeldranfield7140 It's not a big deal in the scheme of things. I find I often have to substitute a different package type when replacing some transistors these days as the original parts are long since obsolete.
Certainly a small price to pay to get a reliable repair.
I just had a same case with a Siemens HF17566 where the bulb caused a short and took the whole control board... Just for fun I replaced it with an Arduino reprogramming all the features. It was fun! 😀
Now the main (bigger) IGBT went shorted, hopefully a replacement for a stronger type will be enough for years... 😅
Bosch/Siemens/Neff ist Qualität! Diese Geräte MUSS man am Leben erhalten! Weil sie den Billigschrott von Bauschlecht u.s.w. überleben werden!
Use to be quality, I have seen very new neff models and they are made in china by Midea , the old stuff is by far the best.
16:40 @MikesElectricStuff covered this way back in 2017, which prompted me to do an insulation modification. Of course, the lamp hasn't blown since, but .... peace of mind!
Back in 2017 the micro controller was still available as a spare part so not doing the mod just meant a repair for another day, however the chip is now no longer available so the mod is essential.
Could you do a follow up of WHY that missing earth turns the microwave into a useless metal box? Intriguing. Love your videos and your knowledge Michael. Thanks for your help!
Don't ask, leaving this out by mistake cost me a lot of money once , it completely wrote off the front panel of the microwave.
would you recommend taking out the bulb in this brand and type of microwave to stop it blowing the track and killing the micro
You could take out the bulb but then you won't see your food cooking but you could swap the bulb for a led type if you don't want to fit a plastic sheet. You can buy led microwave now.
could put a low value resistor or fusible one in line would stop horrendous current surge
Now isn't that weird I have 2 of those microwaves looking for that board , I'm watching
New prices of these boards and genuine Panasonic magnatrons have risen so much in recent months it makes the job not worth repairing, prices have risen significantly pdcause parts are becoming obsolete
.
@michaeldranfield7140 yes I know I work on alot of domestic appliances and used to deal with "emw" for reconditioned timer boards but they've gone bust and back in the 90s I dealt with that mw spares company . Would you be available to post control boards to for recon?
When the first Panasonic inverter microwaves came out we were told not to try and fix them but we had to send the failed boards back to Panasonic
Yes, this happened just the same when Sharp released the Cs chassis TV and we were told it was bacsuse Sharp wanted to build up a history of the problems to aid future development so I guess it was the same with Panasonic.
Neff or Naff?
These were made by Panasonic so quite good, the new Neff ovens are made by midea in China so realley naff.
Great another video,
Many thanks
Thanks for this, I'm going to fit that plastic sheet between the boards on my Neff, do you just push it up between or did you have to remove the top board?
Might be possible to push it up, I prefer to take the back board off though to make sure it's in the correct place.
the last magnetron I had from magsells kept overheating and logging fault codes, bounced twice, could never get it to do it in the workshop. It had alot less fins than the original
I have only ever had a faulty one from Magsells and they just swapped it for me , they tell me there's only 2 or 3 places in the world manufacturing magnetrons
I've had a few brand new Panasonic Inverter microwaves apart recently and I was surpised to see the magnatrons used in them now have Panasonic part numbers and the same style labels but they do not have Panasonic written on them anywhere! Just the part number and made in China. So if you see new magnetrons for sale that have the Panasonic style label and just a part number then there is a chance it could actually be genuine.
I've also noticed the quality on these more recent Panasonic microwaves are awful, especially the slimline combo's. I've never seen sheet metal so thin and the convection fan runs off a square rubber band and pulley, these often make an odd noise and can be fixed by bending the stupidly thin brackets so both pulleys are inline, otherwise the belt twists and also flaps all over the place.
The smaller non-inverter Panasonic microwaves seem to be manufactured Galanz.
Sadly this is common now, everything is produced cheaper, usually in China and won't last as long as it use to.
Hello Michael, A bit off topic but could you make a video explaining how to match up a mosfet with an equivalent. Its always been a hassle for me to ensure that the part i am installing is the right replacement. Talk about Rds(on), Vgs, Id, etc. As an example i have a FQPF5N50C and want to replace it with a STP9N60M2. The specifications on the replacement are better but the Rds(on) differs a lot. Can you help?
Rds on needs to be as low as possible , dont think it will matter if the replacement is lower but if its higher the device will dissipate extra heat
@michaeldranfield7140 Yes, the Rds(on) of the original is around 1.4 ohm but the replacement is 0.78 ohms
Michael could you tell me where do you find the service manual for Neff Microwaves, I tried Google without success.
This oven was made by Panasonic but just badged up NEFF , you need to search for Panasonic
i used to repair microwaves in Namibia
Do you have a link to the inverter board schematics?
Panasonic don't publish the whole schematic of the board and the diagram I have was found on the Internet over a year ago but I suspect is was copied out of the back of a microwave service manual
i remenber working for Smith and Associares it is USA company in Holland and we used to have an Xray machine for fakes
@22:50 with a fake 'EC' (CE???) mark....
Doesn't give a lot of confidence
So a bad Earth in house wiring will kill it
No, this wire is the earthy end of the inverter high voltage supply, without it you get high voltage arc every ware and it kills the front panel.
I now know just enough to know not to try repairing one.
¿ 💩 🤬 💩 ¿
Deutscher Titel, deutsche Beschreibung - für ein englischsprachiges Video? Was soll das?
Igbt substitution is a bit involved, it's not only about rated current etc, since there are several generations now, with differences in hard switching capabilities, gate capacitances, dI/dT acceptance vs external gate resistor, avalanche ratings, and other factors like presence or not of integrated antiparallel diode and driving requirements and temp derating characteristics. Cheap circuits don't use good driving schemes and often fry the gate with OV and that leads to immediate destruction. Good luck on this...
I know, that's why I only just released this video now, the mod I did was nearley 12 months ago and it's still working fine.
God...way too much dribble not enough meat.
18:46
I saw someone on YT repair a magnetron. There are two caps under
the cover. One or both will ? short ? (if I remember correctly) maybe open . They
are in parallel with a low resistance coil, so it is hard to measure
them in circuit. I believe the only other way magnetrons fail is when
their heating element opens. I don't think I have seen any one
replace the heating element. I would probably only attempt the cap replacement in a tight pinch or emergency.
The two RFI caps are within the filliment terminals and not separate but as you say they sometimes go leakey to earth and it's just a matter of replacing the terminal itself.