Microwave RIP?

kuepper

It's going through the motions as normal but at the end of the time period it hasn't heated anything, is this the end of its lifespan or is there a simple fix to try?

Section62

kuepper said:

It's going through the motions as normal but at the end of the time period it hasn't heated anything, is this the end of its lifespan or is there a simple fix to try?

DIY fixes aren't really advised, it needs a professional to diagnose and fix, and the cost of that needs to be weighed against the cost of buying a new one.  (if it is out of guarantee a repair is unlikely to be economic unless the model is an expensive one)

GDB2222

As Section62 says, except that on some microwaves you can turn the power down. You have not turned it down to zero inadvertently, have you?

kuepper

GDB2222 said:

As Section62 says, except that on some microwaves you can turn the power down. You have not turned it down to zero inadvertently, have you?

No, but it was worth a try, I hadn't thought of that!

Bendy_House

Do you have a local appliance repair cove, who'll charge only a smallish diagnostic fee to have a look?

I'm not going to encourage you to open it up because there are some VERY high voltages running around in there (waaay above mains) AND some muckle capacitors that'll store it AFTER the machine has been unplugged = recipe for a giant, permanent, ouch. But there is also a high voltage fuse that is prone to popping every couple of years. Pennies to replace if it's that.

Make and model? Is it worth it?

Another 'common' fault is one of the door microswitches failing, but that usually does more than just fire the magnetron - you'd expect, say, the TT to not turn. Sometimes pulling gently at the door will make it temporarily work. 

You don't recall hearing a pop at any time?

And then the magna itself can fail, and would make it beyond eco repair.

Section62

Bendy_House said:

Do you have a local appliance repair cove, who'll charge only a smallish diagnostic fee to have a look?

I'm not going to encourage you to open it up because there are some VERY high voltages running around in there (waaay above mains) AND some muckle capacitors that'll store it AFTER the machine has been unplugged = recipe for a giant, permanent, ouch. But there is also a high voltage fuse that is prone to popping every couple of years. Pennies to replace if it's that.

Make and model? Is it worth it?

Another 'common' fault is one of the door microswitches failing, but that usually does more than just fire the magnetron - you'd expect, say, the TT to not turn. Sometimes pulling gently at the door will make it temporarily work. 

You don't recall hearing a pop at any time?

And then the magna itself can fail, and would make it beyond eco repair.

Seriously, it simply isn't worth attempting DIY repairs on microwaves (except changing the plug fuse).  It isn't just the high voltages, there is the risk of microwave leakage which can cause permanent damage to health (e.g. hasten the formation of cataracts)

Repairs are unquestionably something which needs to be left to a professional.

E.g. The door microswitches are an essential safety feature to prevent microwave energy being created with the door not properly closed.  Attempting a bodge repair of those is extremely dangerous.  If it is necessary to 'gently pull' on the door to get it to work then it is a huge, massive, enormous sign that you shouldn't be using the microwave anymore - if you place a normal level of value on your health and safety.

Bendy_House

You are technically correct, S62, and I don't want anyone to open one up without being 100% certain they know what they are doing.

Our last micro was a large 40L Sharp which did everything. The one previous to that a Samsung. Both went 'pop' more than once over their lives, and the inline, high-voltage fuse was the culprit. Literally pennies to sort a £300+ oven.

Yes, you need to be careful with micro leakage, but the covers SHOULD come off and go back on very positively, with no concern about gaps.

And the 'pulling on the door' was a test procedure to see if the m'switch might be at fault; it certainly shouldn't be run like that.

It's hard - well, impossible - to judge from this side of the screen who is competent and who is not. But that is true of all sparky work, and even more mundane tasks. But I certainly won't be the only layman who CAN take a MO apart safely.

Maybe you are right, tho'; perhaps NO 'encouragement' should be given?

Section62

Bendy_House said:

You are technically correct, S62, and I don't want anyone to open one up without being 100% certain they know what they are doing.

Really you can only be 100% certain if you have access to (and use) the manufacturer's service manuals, and follow the instructions precisely.

E.g. The high voltage fuse blowing is likely to be a symptom, not the 'culprit'.  Replacing the HV fuse without completing all the other service actions stipulated by the manufacturer means not making a 'safe' repair.  Depending on the make/model there may be other components which must be replaced in addition to replacing a fuse.

Bendy_House said:

But I certainly won't be the only layman who CAN take a MO apart safely.

The real issue is whether these laypeople can put one back together safely.  Microwave ovens are something where a little bit of knowledge is a dangerous thing.  IMV you are right that no 'encouragement' should be given, and I hope for their own safety that kuepper took that on board from the first reply on this thread.

Bendy_House

It's a toughie, and not quite that straight forward, I don't think.

That fuse is known as a not-uncommon issue, and does not necessarily indicate a further issue; they just 'go' now and then, often with a very audible pop.

I know that I am clued up enough to remove the casing from a MO and replace it afterwards in exactly the same way. I know to make the internals safe before handling stuff. And I suspect that you do too.

So, on more than one occasion I have repaired a MW for a few pennies. I have also repaired one by replacing the door MSs, and these clip perfectly in place and cannot be fitted incorrectly. And on the Samsung - a nifty 'guiding light' model, I also repaired the scroll wheel when a solder joint failed on it.

I can do these things safely, and obviously many others can do. Do we preclude them from such repairs? If so, where do we stop - no advice or fitting a Hive, for example, 'cos of dangerous mains voltages/risk of damage to the boiler?

I'm not arguing, because I kind of think you are right - there are some appliances (boilers, MW ovens, etc) that perhaps should be off limits?

Woolsery

Bendy, our Panasonic Multi Function 'went' last week, though no bang audible above the noise our grandchildren make. When I opened it up to look for the high voltage fuse, I couldn't see one, so gave up without any extensive dismemberment. The thing is 12 years old after all and I have £300 of nectar points going mouldy....

Could you confirm there's no easilly accessible HV fuse on these? I'd expected the fuse to be easily acessible near the mains lead entry, but if it's likely to be somewhere else I'm willing to take a look with due care about stuff like capacitors.

It's a NN-CF760M or NN -CF750W

Sorry kuepper for the hijack! 

Section62

Woolsery said:

Bendy, our Panasonic Multi Function 'went' last week, though no bang audible above the noise our grandchildren make. When I opened it up to look for the high voltage fuse, I couldn't see one, so gave up without any extensive dismemberment. The thing is 12 years old after all and I have £300 of nectar points going mouldy....

Could you confirm there's no HV fuse on these. They still look much the same visually.I'd expected the fuse to be easily acessible near the mains lead entry, but if it's likely to be somewhere else I'm willing to take a look with due care about stuff like capacitors.

It's a NN-CF760M or NN -CF750W

Sorry kuepper for the hijack! 

I'd suggest Bendy (or anyone else) would be very unwise to offer you advice on repairing your microwave.  Anyone who doesn't know where to look for the HV fuse doesn't have the required level of competence to replace one safely.

These things can kill people.  Don't mess around with them.