Do the high voltage capacitors in a microwave contain any fluid that can leak out when defective? I have seen the electrical capacitors you show in your video burst and leave a fiber material all around it . The one in the microwave has a pool of clear oily liquid that smells like 3in1 oil right under the capacitor and is spread along the entire channel that serves as the rear feet of the microwave. The microwave works but I find this very odd. No one mentions oil as common problem with the capacitors. In fact they say they are dry. Any thoughts?
Just an update for those who want to know, these are filled with OIL to cool them, not the old illegal stuff but some oil like product. The Sharp microwave was leaking it constantly after I clean the floor of the microwave up oil would seep out more after use. I found an exact replacement on eBay supposedly pulled from working blemished units.
Another way to check if the electrolytic cap is defective is by checking the pins under it. If it looks like rubber part at the base has cracked on it, it is already dried. If there some kind of white excess of internal chemical paste that leaked out from the pin terminal, again, it is also dried.
Most people only check ESR today, which can fool them with shorted caps. Leakage causes more problems than anything else but is seldom considered. I have rescued many items others had given up on because of this.
I agree, many people started to make arguments with me regarding ESR (most of the time they use DIY ESR meters), however in my experience, in practice, it is very unlikely that an electrolytic capacitor does not show the problem in the capacity also (third case). Most of the time electrolytic capacitors show problems, polyester ones are much less likely to fail easily
What about ceramic capacitors? I’m currently struggling to find the cause of low grid current in a vacuum oscillator induction furnace and it’s driving me nuts. All of the caps measure fine disconnected, chokes are fine, resistors fine, no shorts I can find. Only thing I can think of is capacitor failure under load (which I thought was extremely rare) or a bad signal transformer on the RF Furnace board.
it depends on where they have been used. if you watched this video completely, the most tricky case is the third one. so you have to use an LCR meter. I'm not familiar with your device however sometimes resistors look fine but the value has been changed. if your device malfunctions when it is cool, then the problem is easier to spot
@@MyVanitar unfortunately it only acts up during sample analysis. (This is a Carbon / Sulfur analyzer by way of induction combustion and NDIR detection). The frustrating thing is it doesn’t throw any errors so the oscillator tube just sits there glowing red hot destroying itself. I’m not an electrician, so in depth stuff on a component by component basis isn’t the easiest for me. I just ordered everything inside the furnace from the office, so I’ll try a shotgun approach and report back lol. The furnace generates 12kV and heats stuff up to about 2000C, so it’s a boss for sure.
the power supply is switching? if yes and it works more than 3-4 years, check the capacitors for drying. especially the first one (big capacitor near the bridge rectifier)
@@MyVanitar finally figured it out. PSU was fine, rectifiers were good…it ended up being 2 500pF ceramic capacitors before and after the oscillator tube, the potted grid capacitor and potted plate capacitor, but the frustrating thing is they seemed fine when measuring. It was capacitor failure under load, but I don’t have any idea how it happened. The ceramic caps are $90 each, the grid cap is $440, and the plate cap costs….$1010. Total bill, $13,500. Customer was thrilled their $100,000 instrument could start making them money again so that’s all that matters I guess :). Thanks for the help.
Please could somebody advise me I have a board with a 47uf 16v capacitor but it’s showing 197uf, I can’t find any video to explain a higher reading, is it a good one holding lots of charge or bad one? Please someone help as I have a problem with the board and this is the only thing I can find wrong
A higher reading is possible but not this much (+/- 20%), you need an LCR meter to test the capacitors correctly, I don't mean an expensive one, but it must be an LCR meter. Multimeters measure capacitors by timing, not pulses
@@MyVanitar do you mean what I’m trying to fix? If you do it’s a technics PX1M digital piano, very very old but worth fixing if I can find out why it’s making a distortion sound
@@MyVanitar He's asking what's wrong with that cap at 0:40. I'm guessing you meant the bottom is bulging out, but I can't tell from the few frames it was in focus.
NoT currently right i built a buck converter and i use a 3300uf blue coler amplifier capacitor the current storge was very large and i get 21 amp easy from it but i use another 3300 capacitor nichicon caps it test good on my caps tester and i get zero amp storage from it so u dont know that there or 3 type of ekectrical caps filter caps that hold high current and smb caps that dont how enery just act as low pass filter for clearing frequency repple and high frequency caps for enery delay
it's very unlikely that increasing the ESR does not affect the capacitance also (in practice), so as I explained for the last case and the 22uF capacitor, if you even read 16-17, then definitely you need to replace it.
Yes, SMD electrolytic capacitors are slightly better, because of the lower ESR, however, they are limited in capacity and the rated voltage, I mean the variety of them is lower than through-hole ones
@@MyVanitar That's interesting. I assumed they'd be identical apart from the way they're mounted. Anway, I use SMD electrolytics for assembled PCBs, since they're cheaper to assemble.
Nothing wrong with electrolytic capacitors. They are either used wrong or built wrong ! I have many industrial machines with capacitors that are at least 30 years old. The capacitors are perfectly fine. The problem is they are used improperly. First : Buy capacitors from a reputable BRAND and SOURCE. Those nichicons from ebay most likely are not real nichicons... Second : understand the parameters of the capacitor you are buying. Blindly "going low esr" is useless. The lower the ESR the higher the ripple current will be through the capacitor. There is such a thing as too low an ESR for a specific application ! In the early 2000's we had capacitor plague caused by somebody that stole a electrolytic chemistry but did not have the complete formula. The stolen chemistry ended up in many caps and they all started popping. In the 2000's the formulation of the electrolytic went from a ethylene-glycol base to water based. Without a stabilizing agent the water will hydrate the aluminum electrodes, release gas and the capacitor pops. Long life capacitors use an electrolyte like DMF or DMA (Dimethylfomamide or DemethylAcetamide) . A second problem is that the electrolyte can react with the rubber seal around the pins. Third problem is the improper, or no, cleaning of the board after soldering. Flux is a corrosive agent and will attack the rubber to pin seal causing the capacitors to leak. some cleaning agents to remove flux are very aggressive and may damage the rubber seal as well. You need to check that your cleaning agents are compatible with the parts ! RoHS and WEE have demanded changing the composition of the gaskets and you cannot use the same cleaning agents you used 50 years ago. The formulation is different ! Another common misunderstanding is the cleanup after removing a defective capacitor. The electrolyte ate the traces. Not true. The leaking electrolytic fluid has create metal salts. These salts are conductive. the voltage between the pins creates a current in the salts and eats away the traces. Cleaning that off requires that you know what electrolyte was used. for Water based electrolytes : distilled water with either a bit of ammonia or vinegar. For the others : mechanical scrubbing. Testing a capacitor with an ESR meter is also useless unless you know the esr for that particular capacitor model and family. Blindly going "it's 0.9 ohm which is good for a 2200uF " means nothing. It depends on manufacturer and model. For some 1.5 ohm may be perfectly fine ! Even then, you may measure an acceptable ESR and value but the thing leaks (electrically)! Leakage testing can only be done by charging the capacitor to its rated voltage and monitoring the residual current or the rate of self-discharge. You cannot do this with a regular multimeter. You are either fishing for nano or pico amps and will have to have a long charge time, or you are looking for voltage droop and then the input impedance of a regular multimeter is too low. Most digital meters are 10Megaohm input impedance. a capacitor charged to 50 volts means that you are pulling 5 microampere just by attaching your meter. The droop needs to be measured with an electrometer (Teraohm input impedance) and you still will have to wait along time to see the voltage drop and then figure out the maths.
Thanks for your professional experience.
Check this one also: th-cam.com/video/CGDtfCkGk2A/w-d-xo.html
Do the high voltage capacitors in a microwave contain any fluid that can leak out when defective? I have seen the electrical capacitors you show in your video burst and leave a fiber material all around it . The one in the microwave has a pool of clear oily liquid that smells like 3in1 oil right under the capacitor and is spread along the entire channel that serves as the rear feet of the microwave. The microwave works but I find this very odd. No one mentions oil as common problem with the capacitors. In fact they say they are dry. Any thoughts?
this is only one sign of a failed capacitor, watch my next video for a complete solution: th-cam.com/video/CGDtfCkGk2A/w-d-xo.html
Just an update for those who want to know, these are filled with OIL to cool them, not the old illegal stuff but some oil like product. The Sharp microwave was leaking it constantly after I clean the floor of the microwave up oil would seep out more after use. I found an exact replacement on eBay supposedly pulled from working blemished units.
@@tombanes Thank you
Another way to check if the electrolytic cap is defective is by checking the pins under it. If it looks like rubber part at the base has cracked on it, it is already dried. If there some kind of white excess of internal chemical paste that leaked out from the pin terminal, again, it is also dried.
Yes, thank you for your comment
Most people only check ESR today, which can fool them with shorted caps. Leakage causes more problems than anything else but is seldom considered. I have rescued many items others had given up on because of this.
I agree, many people started to make arguments with me regarding ESR (most of the time they use DIY ESR meters), however in my experience, in practice, it is very unlikely that an electrolytic capacitor does not show the problem in the capacity also (third case). Most of the time electrolytic capacitors show problems, polyester ones are much less likely to fail easily
What about ceramic capacitors? I’m currently struggling to find the cause of low grid current in a vacuum oscillator induction furnace and it’s driving me nuts. All of the caps measure fine disconnected, chokes are fine, resistors fine, no shorts I can find. Only thing I can think of is capacitor failure under load (which I thought was extremely rare) or a bad signal transformer on the RF Furnace board.
it depends on where they have been used. if you watched this video completely, the most tricky case is the third one. so you have to use an LCR meter. I'm not familiar with your device however sometimes resistors look fine but the value has been changed. if your device malfunctions when it is cool, then the problem is easier to spot
@@MyVanitar unfortunately it only acts up during sample analysis. (This is a Carbon / Sulfur analyzer by way of induction combustion and NDIR detection). The frustrating thing is it doesn’t throw any errors so the oscillator tube just sits there glowing red hot destroying itself. I’m not an electrician, so in depth stuff on a component by component basis isn’t the easiest for me. I just ordered everything inside the furnace from the office, so I’ll try a shotgun approach and report back lol. The furnace generates 12kV and heats stuff up to about 2000C, so it’s a boss for sure.
the power supply is switching? if yes and it works more than 3-4 years, check the capacitors for drying. especially the first one (big capacitor near the bridge rectifier)
@@MyVanitar finally figured it out. PSU was fine, rectifiers were good…it ended up being 2 500pF ceramic capacitors before and after the oscillator tube, the potted grid capacitor and potted plate capacitor, but the frustrating thing is they seemed fine when measuring. It was capacitor failure under load, but I don’t have any idea how it happened. The ceramic caps are $90 each, the grid cap is $440, and the plate cap costs….$1010. Total bill, $13,500. Customer was thrilled their $100,000 instrument could start making them money again so that’s all that matters I guess :). Thanks for the help.
Do you have an LCR meter? please check the value of the failed capacitors and inform me
Please could somebody advise me I have a board with a 47uf 16v capacitor but it’s showing 197uf, I can’t find any video to explain a higher reading, is it a good one holding lots of charge or bad one? Please someone help as I have a problem with the board and this is the only thing I can find wrong
A higher reading is possible but not this much (+/- 20%), you need an LCR meter to test the capacitors correctly, I don't mean an expensive one, but it must be an LCR meter. Multimeters measure capacitors by timing, not pulses
@@MyVanitar thank you for your reply, I have ordered a new one so will try replacing it and see if it solves the problem 👍🏻
which model?
@@MyVanitar do you mean what I’m trying to fix? If you do it’s a technics PX1M digital piano, very very old but worth fixing if I can find out why it’s making a distortion sound
No I mean what LCR meter did you buy
Nice video .Coud you make a video about"How understand "Capacitor's leaguge problem"?
Do you mean capacitor's leakage? let's see what happens in future
@@MyVanitar yes certainly .Also please describe "high leakage problems in circuit (on board )too" Thank you
Hello what's a 3n3 capacitor?
I don't have such a thing in this video
At :40,..what the heck does "like this" mean?
similar to this
@@MyVanitar He's asking what's wrong with that cap at 0:40. I'm guessing you meant the bottom is bulging out, but I can't tell from the few frames it was in focus.
@@stimtab I have another video that concludes everything regarding capacitors using a professional LCR meter: th-cam.com/video/CGDtfCkGk2A/w-d-xo.html
Thank you very much!
glad it was helpful
NoT currently right i built a buck converter and i use a 3300uf blue coler amplifier capacitor the current storge was very large and i get 21 amp easy from it but i use another 3300 capacitor nichicon caps it test good on my caps tester and i get zero amp storage from it so u dont know that there or 3 type of ekectrical caps filter caps that hold high current and smb caps that dont how enery just act as low pass filter for clearing frequency repple and high frequency caps for enery delay
What's your question? try to test the caps using an LCR meter. timing method is misleading. if it was more than 10% OFF in value, replace it.
yes I use my LCR multiple tester and the v.losses was 20% on the cap that didn't hold any current
Heat on top of cap producing sound if it work fine then its faulty
I'll publish another tutorial in the next few days, a good one
Even easier, if it is a through hole type on a PCB it’s old and probably bad. Just replace it.
That's another option, right
Sometimes it show a good value but high ESR
it's very unlikely that increasing the ESR does not affect the capacitance also (in practice), so as I explained for the last case and the 22uF capacitor, if you even read 16-17, then definitely you need to replace it.
nice
my capacitors is 2200uf but it shows 4000+ uf.
I have no idea, check if the battery of your LCR meter is okay
always show in comparison :)
That's right
Electrolytics are the worst components ever! We really should invent an alternative to high capacity capacitors.
SMD ones are slightly better, because of the lower ESR
@@MyVanitar I always use ceramic SMD where I can. Are you saying SMD electrolytics are better than through-hole electrolytics? I didn't know that.
Yes, SMD electrolytic capacitors are slightly better, because of the lower ESR, however, they are limited in capacity and the rated voltage, I mean the variety of them is lower than through-hole ones
@@MyVanitar That's interesting. I assumed they'd be identical apart from the way they're mounted. Anway, I use SMD electrolytics for assembled PCBs, since they're cheaper to assemble.
Nothing wrong with electrolytic capacitors. They are either used wrong or built wrong ! I have many industrial machines with capacitors that are at least 30 years old. The capacitors are perfectly fine. The problem is they are used improperly. First : Buy capacitors from a reputable BRAND and SOURCE. Those nichicons from ebay most likely are not real nichicons... Second : understand the parameters of the capacitor you are buying. Blindly "going low esr" is useless. The lower the ESR the higher the ripple current will be through the capacitor. There is such a thing as too low an ESR for a specific application ! In the early 2000's we had capacitor plague caused by somebody that stole a electrolytic chemistry but did not have the complete formula. The stolen chemistry ended up in many caps and they all started popping. In the 2000's the formulation of the electrolytic went from a ethylene-glycol base to water based. Without a stabilizing agent the water will hydrate the aluminum electrodes, release gas and the capacitor pops. Long life capacitors use an electrolyte like DMF or DMA (Dimethylfomamide or DemethylAcetamide) . A second problem is that the electrolyte can react with the rubber seal around the pins. Third problem is the improper, or no, cleaning of the board after soldering. Flux is a corrosive agent and will attack the rubber to pin seal causing the capacitors to leak. some cleaning agents to remove flux are very aggressive and may damage the rubber seal as well. You need to check that your cleaning agents are compatible with the parts ! RoHS and WEE have demanded changing the composition of the gaskets and you cannot use the same cleaning agents you used 50 years ago. The formulation is different ! Another common misunderstanding is the cleanup after removing a defective capacitor. The electrolyte ate the traces. Not true. The leaking electrolytic fluid has create metal salts. These salts are conductive. the voltage between the pins creates a current in the salts and eats away the traces. Cleaning that off requires that you know what electrolyte was used. for Water based electrolytes : distilled water with either a bit of ammonia or vinegar. For the others : mechanical scrubbing. Testing a capacitor with an ESR meter is also useless unless you know the esr for that particular capacitor model and family. Blindly going "it's 0.9 ohm which is good for a 2200uF " means nothing. It depends on manufacturer and model. For some 1.5 ohm may be perfectly fine ! Even then, you may measure an acceptable ESR and value but the thing leaks (electrically)! Leakage testing can only be done by charging the capacitor to its rated voltage and monitoring the residual current or the rate of self-discharge. You cannot do this with a regular multimeter. You are either fishing for nano or pico amps and will have to have a long charge time, or you are looking for voltage droop and then the input impedance of a regular multimeter is too low. Most digital meters are 10Megaohm input impedance. a capacitor charged to 50 volts means that you are pulling 5 microampere just by attaching your meter. The droop needs to be measured with an electrometer (Teraohm input impedance) and you still will have to wait along time to see the voltage drop and then figure out the maths.