When I worked at Mastercare they had a “customer education” charge of £30.00 if the call out was something stupid like flat batteries in the remote or the appliance was unplugged, we called it the “Idiot charge” I had a call to a digital microwave for a timer fault, it was in a very posh area with an equally posh customer. “There’s something wrong with the display countdown, look ( demo by customer ) I set it to 1.30 ( one minute and thirty seconds) and when it gets to 1.00 ( 1 minute) it suddenly jumps to 59 instead of 99.” After a brief explanation of how many seconds are in a minute I left along with £30.00.
Agreed, “The 3 Ds” Disconnect from mains supply, Door open for interlock isolation, Discharge HV capacitor. Never had a capacitor crack over when shorted but the one you don’t do may be the one that kills you!
@@steve83803 on a microwave training course we were told to disconnect the mains plug and place it inside the oven, this ensures the door stays open and no one else can accidentally plug it into the mains .
Used to be a problem on the pre inverter Panasonics, the wire would work loose in the crimped terminal and cause intermittent operation. Rightly or wrongly, I used to flow a bit of solder into the crimp. Never had any come back failed again.
@@michaeldranfield7140 yes, very similar. I was working for BSH home appliances so they were essentially the same Panasonic units with a build-in kit strapped to them
Note it is Very Dangerous to open a Microwave if the main Capacitor is charged up it can have 2500 Volts on it when on load and 5000 Volts off load sometimes if a fault occurs. THIS HI VOLTAGE WILL KILL YOU. SO IMPORTANT TO DISCHARGE THE CAPACITOR SAFELY FIRST WITH A WELL INSULATED LEAD CONNECTED TO EARTH FIRST . Best left for Experiencend Engineers to Service
Another interesting video - thank you for sharing it with us. Surely such an important connection should be made with something better than a "push on" connector? Why couldn't they have used a "bolt on" type connector that made a perfect connection 100% of the time?
@@opapagaio15 of course, and the makers need to keep selling new ones as there not making the money they use to , I remember selling 0.8 cu ft microwaves back in the late 80 s at £99 , now 40 years later a same size oven can be bought for £40.
@@michaeldranfield7140 They'll soon fix the problem by turning on the subscription fee for 2€ a month you'll get the ability to use the IA powered pop corn program, and the ultra fancy defrosting one ! (Note for the IA pop corn soon to be rented, Sharp made one in the late 90"s that include a microphone that stop the waves after something like 2 sec without a pop)
Thanks! Contact problems are a very common reason for all sorts of failures. I would also add oil (universal lubricant spray) to the cleaned contacts to prevent oxidation.
These spade terminals don't seem to perform well in high current applications. I've seen the same problem so many times in Computer UPS supplies where they fail in low voltage/ high current battery connections.
I think you don’t see these soldered because of heat and the low melting point of solder. Same in toaster ovens, coffee makers, etc. Spot welding may help, but that makes servicing a bit harder.
Of course , a microwave is a dangerous item , in fact when I first started repairing microwaves back in the early 90s no one would supply with spare parts until you had passed a recognised microwave training course but these days anybody can buy spare parts on the internet regardless of what qualifications you have or don't have .
@@michaeldranfield7140 Unfortunately the same is not true for pressure cooker, the well know one SEB forbid to sold safety valves, so instead of replace it when it come leaky, I see some simply remove it and close it with gasket and stainless bolt. It work perfectly, you just need to rely on the "last resort" safety that will make the arch on the lid bend allowing the stem to go out. This was the smartest part of the design making it fully explosion safe.
Thank you very much for this tip!!! However i am somewhat surprised that the filament current is so damn high. Do you have an idea what is the reason why they run the microwave filament that high on current and let's say simple valves are relatively low on current ?
Its a very high power device with a relatively low efficiency , some transmitting tubes run at a ridiculous heater current, the 4CX10,000D needs 7.5 volts at 78 amps !
Probably wrong but id it possible the connector that welded on eas carrying more current than rated cause of the other connection being loose. Great video thanks.
@@michaeldranfield7140 well... No cos the very FIRST one to start burning would then be the ONLY one with "resistance" causing ALL the voltage to be dropped across it. The other connector would then become the "better" connection. Also the carbonized one would continue to get worse due to more resistance across it thereby producing more carbon.
I can understand why the manufacturer uses plugs for the heater wires but for a repair wouldnt a soldered connection be the best route? (and save the cost of replacement connectors....)
no safety warning comes with spare parts when customers just buy them off the internet , when I first started doing microwaves no one would supply you with spare parts unless you had passed a recognised microwave safety course, now anybody can buy any part from the internet regardless of what they know or dont .
Call this "natural selection" this come with a free inscription to the Darwin awards ! Luckily for those who play with TV sets the voltage was higher but with far less capacity so they can survive the shock !
When I worked at Mastercare they had a “customer education” charge of £30.00 if the call out was something stupid like flat batteries in the remote or the appliance was unplugged, we called it the “Idiot charge”
I had a call to a digital microwave for a timer fault, it was in a very posh area with an equally posh customer.
“There’s something wrong with the display countdown, look ( demo by customer ) I set it to 1.30 ( one minute and thirty seconds) and when it gets to 1.00 ( 1 minute) it suddenly jumps to 59 instead of 99.”
After a brief explanation of how many seconds are in a minute I left along with £30.00.
Make sure the high voltage capacitor is discharged before touching terminals
Agreed, “The 3 Ds” Disconnect from mains supply, Door open for interlock isolation, Discharge HV capacitor. Never had a capacitor crack over when shorted but the one you don’t do may be the one that kills you!
sucking eggs comes to mind.🤔
of course, don't just rely on the internal 10Meg resistor inside the high voltage capacitor , I have had these go open circuit many times .
@@steve83803 on a microwave training course we were told to disconnect the mains plug and place it inside the oven, this ensures the door stays open and no one else can accidentally plug it into the mains .
Seem to remember it was Sharp with the 3Ds we started repairing Microwave ovens at Masterscare and all had to complete the course.
Great video Michael. Thanks for taking the time to do this
Many thanks for that .
Mine did exactly this I just tightened all the crimps up and 15 years later still working.
What a strange outcome I would of thought the loose one would of been burnt lol thanks Michael 😊
you would have thought so .
Another great video Michael, thanks for taking the time to put this up. 😄
Many thanks for watching .
Used to be a problem on the pre inverter Panasonics, the wire would work loose in the crimped terminal and cause intermittent operation.
Rightly or wrongly, I used to flow a bit of solder into the crimp. Never had any come back failed again.
like the one the service manual is for ! I did the same on this solder the connection after crimping , I'm not a big fan of just relying on the crimp.
@@michaeldranfield7140 yes, very similar. I was working for BSH home appliances so they were essentially the same Panasonic units with a build-in kit strapped to them
Thank you Mr. Michael, this is a great informative video. I appreciate it.
Many thanks for that .
@@michaeldranfield7140 you are most welcome
The 'TIGHT ' one Arc welded it onto the Terminal but causing a DRY CONTACT in the process thus couldn't gdt full POWER through.
but you would have thought the loose connection would be burnt also
Note it is Very Dangerous to open a Microwave if the main Capacitor is charged up it can have 2500 Volts on it when on load and 5000 Volts off load sometimes if a fault occurs. THIS HI VOLTAGE WILL KILL YOU. SO IMPORTANT TO DISCHARGE THE CAPACITOR SAFELY FIRST WITH A WELL INSULATED LEAD CONNECTED TO EARTH FIRST . Best left for Experiencend Engineers to Service
Thanks for sharing 👍
No problem , many thanks for watching .
Another interesting video - thank you for sharing it with us. Surely such an important connection should be made with something better than a "push on" connector? Why couldn't they have used a "bolt on" type connector that made a perfect connection 100% of the time?
Some industrial magnetrons do have bolt on terminals but not in the domestic world .
Because then they wouldn't fail at warranty + a day & the makers wouldn't sell as many new microwave ovens.
@@opapagaio15 of course, and the makers need to keep selling new ones as there not making the money they use to , I remember selling 0.8 cu ft microwaves back in the late 80 s at £99 , now 40 years later a same size oven can be bought for £40.
@@michaeldranfield7140 They'll soon fix the problem by turning on the subscription fee for 2€ a month you'll get the ability to use the IA powered pop corn program, and the ultra fancy defrosting one ! (Note for the IA pop corn soon to be rented, Sharp made one in the late 90"s that include a microphone that stop the waves after something like 2 sec without a pop)
Thanks! Contact problems are a very common reason for all sorts of failures. I would also add oil (universal lubricant spray) to the cleaned contacts to prevent oxidation.
These spade terminals don't seem to perform well in high current applications. I've seen the same problem so many times in Computer UPS supplies where they fail in low voltage/ high current battery connections.
Couldn't agree more , they are a disaster in catering equipment such as hotplates and deep fat fryers.
Make sure to discharge the Capacitor before doing anything inside a Microwave.
Absolutely , don't rely on the internal 10 meg resistor inside the capacitor , I have had these go open circuit many times .
Would a soldered joint not be better, or could that damage the magnetron internally?
I think you don’t see these soldered because of heat and the low melting point of solder. Same in toaster ovens, coffee makers, etc.
Spot welding may help, but that makes servicing a bit harder.
I dont think you would damage the feedthrough capacitor by soldering but it would have repairing harder in the future .
🤔 cheers, if you’re not sure leave well alone, these things can kill
Of course , a microwave is a dangerous item , in fact when I first started repairing microwaves back in the early 90s no one would supply with spare parts until you had passed a recognised microwave training course but these days anybody can buy spare parts on the internet regardless of what qualifications you have or don't have .
@@michaeldranfield7140 Unfortunately the same is not true for pressure cooker, the well know one SEB forbid to sold safety valves, so instead of replace it when it come leaky, I see some simply remove it and close it with gasket and stainless bolt. It work perfectly, you just need to rely on the "last resort" safety that will make the arch on the lid bend allowing the stem to go out. This was the smartest part of the design making it fully explosion safe.
Cannot believe he never mentioned how dangerous it is to play around with a magnetron and associated capacitor. Can be lethal.
great info, thanks
Many thanks for watching .
Thank you very much for this tip!!! However i am somewhat surprised that the filament current is so damn high. Do you have an idea what is the reason why they run the microwave filament that high on current and let's say simple valves are relatively low on current ?
The power of the magnetron is about 800W and the tubes are about 30,40W.And there are thermal loses in the magnetron that draw current.
Its a very high power device with a relatively low efficiency , some transmitting tubes run at a ridiculous heater current, the 4CX10,000D needs 7.5 volts at 78 amps !
Whenever I repair a microwave I cut off the quick-disconnect terminals and solder the wires to the connections. Mostly on the door switches.
Probably wrong but id it possible the connector that welded on eas carrying more current than rated cause of the other connection being loose. Great video thanks.
The ONLY reason the top one was not loose also , was that the corrosion and carbon was "welding " it tight.
of course but you would have expected the other to burn also .
Maybe .@@peacebeuntoyou8934
@@michaeldranfield7140 well... No cos the very FIRST one to start burning would then be the ONLY one with "resistance" causing ALL the voltage to be dropped across it. The other connector would then become the "better" connection. Also the carbonized one would continue to get worse due to more resistance across it thereby producing more carbon.
weird how the loose connection had no burning but the tight one did, i would have thought it would be the other way round
Every microwave I've repaired has been 9 out of 10 times the diode.
I can understand why the manufacturer uses plugs for the heater wires but for a repair wouldnt a soldered connection be the best route? (and save the cost of replacement connectors....)
Soldered connection would be better but it makes fault finding and parts replacement more difficult .
yes, you can see it is loose.
But the loose one is not the burnt one !
very common fault some people leave it a bit late with soghns of burning
I have seen the odd one that's so burnt the magnetron has had to be replaced .
Number of repaired ovens I see where the FA and F are wrong way round.
Don’t you think a prominent safety warning would be appropriate at the beginning?
no safety warning comes with spare parts when customers just buy them off the internet , when I first started doing microwaves no one would supply you with spare parts unless you had passed a recognised microwave safety course, now anybody can buy any part from the internet regardless of what they know or dont .
Unqualified people should not try to repair microwaves..They could end up dead. This video needs to be removed.
Killjoy
the high voltage will discharge automatically when not plugged in , any residual voltage will not kill you
Not true. If there is a fault on the components it may not discharge. The 3 D's...Disconnect..Door open...Discharge..
Call this "natural selection" this come with a free inscription to the Darwin awards !
Luckily for those who play with TV sets the voltage was higher but with far less capacity so they can survive the shock !