Samsung MC32J7055CT . smart microwave oven, some buttons not working on keypad fault.
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- Опубліковано 9 чер 2023
- I went off down the wrong track on this repair for the simple reason the customer said the fault started off intermittent and got worse over time .
- Наука та технологія
![[With Sound] Fix Microwave Keypad Error step-by-step](/img/n.gif)
Excellent! Thank you, Michael! I have that model of microwave and the LCD panel has a fault. Some of the parts of the second digit are not lighting up, so it's giving crazy time readings and the display, when showing text is unintelligible. I'm about to try and find the 'disassembly' instructions and will need one of those control panels that you have successfully replaced. It's really annoying as it's only 18 months old - Murphy's law! Video is very informative and has shown me what the parts look like, and I very much respect the fact that you are willing to share your 'mistakes' (you weren't given all the info by the customer!) that led you to buy a part you didn't need. Top man!
You live and learn, I won't make that mistake again, someone comment this problem is caused by the display itself but as its no longer available I can't test out this theory.
Had the same exact problem on a Sharp unit. 3 buttons didnt work and the display had that funny ghosting. The issue is not with the buttons as one would think, nor the MCU. The problem are the leaking LEDs in the display. The MCU uses the same pins for input and output, multiplexing between sensing buttons and lighting segments. The desing relies on the display LEDs behaving as good diodes, only conducting current one way. When one LED starts to conduct also the opposite way, the MCU will not be able to sense the buttons in the matrix in that row/column. I wasnt able to locate a replacement display module anywhere in the world, it is not sold separately. I finally solved it by soldering series diodes for each display digit on the common pin.
Ah , now that's very interesting, I had a fault in the last 6 months or so where a customer bought me an instrument cluster from a Fiat 500 car and that was caused by a bi direction LED causing different LED s to flash when the indicators were selected, many thanks for this information , I still have the old board so I will check out the LED display and see if it is available as a spare part but as you have already pointed out its probley not available on its own .
Thanks, had 3 buttons not working (2 I never use) so fixed it with a diode on the left most pin of the display
@@FrancSchiphorsthey, sounds like I'm doing the same. Just wanted to be sure before doing it, by "the most left pin" you mean the left one facing the front of display (while reading display correctly let's say), right?
Thank you for sharing this interesting and educational video with us. Why do the model numbers of modern appliances have to be so long? "MC32J7055CT" is far longer that it actually needs to be!
Another job I lost money on !
I have noticed on a lot of stuff now the model numbers are getting bigger .
@@michaeldranfield7140 hehe, yep, my 16 inch lcd tv in the kitchen is something like LCDW16DVDHDF has dvd player in(which conked out just out of guarantee, hmph) , alternative non dvd versions omitted the DVD from the number 😁(you have to be careful with the dvd model at least as there was 2 versions with same number, one had ccfl backlight screen, one led, i have one of each, so far only come across the ccfl of the non dvd version, also they vary widely on pc vga compatibility) some philips numbers were a bit cumbersome, G22K550/05 for a 22 inch G8 chassis tv, some Luxor/Salora ones were a bit long,
Thanks so much Michael
I have same microwave with similar problem
I tried to get this repaired and quote was too high. Have done the assessment as you did with child lock nd changed the pcb for 80 pounds and it works again
Thanks a million 😊😊
No problem at all, glad it helped you.
Thanks for the vid. The diode tip in one of the replies fixed my start button issue.
I first added diodes to the 5 right most pins of the display but that did not fix, then i check all buttons and found 2 more that did not work. After some more tracing with a magnifier i found they connected to the left most pin of the display. Adding a diode there fixed my start button (and the other 2) i just snipped the pin and soldered the diode in between
Diode with the ring on the board and anode connected to the display left most pin (below the start symbol)
Edit: Update 5 days later it stopped again...... to be continued
Edit2: Turns out i mistraced the wires it was the second pin so added another diode (i now have more with than without :D)
I also hooked up the extra start button that i drilled into the front during my previous attempt :D
I will update if it fails again
Thanks a million - I had the same problem but different buttons and by watching this I disassembled it to get the part number. I took a photo of the board and put it all back together - the non-functioning buttons were working again so I'll hold off ordering the part until it has clocked up again and the built in obsolesence kicks back in. I'll never buy samsung again.
Funny you should say this , I had a different model Samsung that wouldn't start when you press the button but everything else worked ok , I quoted for a new board and the customer declined the repair and told me to scrap the machine so I stuck it on a shelf and left it , over a year later I had another in for a different fault and I thought I may be able to find the problem by comparison tests , when I tried the now working one again which had just stood on a shelf it worked ok so something very strange is going on with these boards , its almost like a case of tin whisker growth which was a big problem in the early days of lead free solder.
@@michaeldranfield7140 can also be the diode problem in the display combined with enviromental factors (that i fixed by adding an extra diode on the first pin)
I sometimes had to press start a couple times so maybe the problem is depending on the supply voltage. It's a lot colder here (in the NL) so maybe some components are just a bit out of spec and now voltage is a bit higher /lower so the problem pops up. Because the power rail is just a tad higher/lower or the diodes in the display behave slightly different pushing the issue over the edge.
@@FrancSchiphorst Someone else suggested the LED display but I cant say as the display is now no longer available from Samsung but I still have the old board to play about with .
Well done Michael. When you think about it I would not be surprised if the HV current in the business end may have caused a problem by spiking a bit of energy into that control board.
While it could be the cause I have another theory, I think it could be caused by tin whisker growth in the micro. This is my reason, I have a different model Samsung smart oven someone brought in for repair over a year ago and it all worked apart from the start button, I quoted the customer for a new control panel but they never came back, so not that long ago I had an identical oven in for repair so I thought I would just try the control panel out of another customers oven just to confirm my diagnosis, however when I tried the oven again it now worked OK, now I have had experience with tin whisker growth in the past with sky boxes and I have seen this behaviour before, leave something that doest work dormant with no power and it mysterious comes back to life.
@Michael Dranfield Well well whisker growth, I am surprised , thought that was confined to old germanium transistors . Trying to get my Arcam going. Faulty regulator replaced , green light comes on now and relays work but no sound because I've lost both supplies -44 / +44 rails to IC201 / IC202 which are cold . You would think it would be simple but despite having a manual and a good lamp my eyesite is not as good as what it used to be . I posted a video of the Amp internals on my channel. At least it looks pretty .
Just had a look, proper TO3 transistors, that's the sign of good build quality.
I've had that problem with two washing machines. Both different makes and both suffered from "software issues" . Rendered them scrap.
someone as just suggested it could be caused by a Leakey LED in the display which I am going to do further investigation into .
For anyone looking for a replacement board, the Samsung part is Pcb Main;rcs-s100gl-24 Mw7000j-pjt. Was around £95 on samsungspares. I bought one from espares for £85 inc delivery.
It's simple enough to replace; refitting the cover took me longer! It fixed this problem. The board from espares claims it is a genuine Samsung part. It certainly looks identical. However, the LED display appears to be set slightly further back then the original. It means elements are hidden if looking from an angle. Maybe Samsung have changed to a different LED assy, if that was indeed what was causing this failure.
These are retail prices on the internet so a lot more than I paid , however its interesting you mention the LED , someone has suggested it could be the LED display itself , which is Highley likely and would be a cheap fix but I have been unable to obtain the exact display as its been discontinued by Samsung .
This is a problem that should have been fixed during R&D development. Shielding issues have been missed here.
everything is made as cheap as possible and nothing ever seems to get recalled these days , as long as it last more than 12 months the manufactures are not bothered.
I have the same problem. We will send it in to Samsung… I hope they will fix it and it won‘t happen again. I somehow think that the opening and closing of the door is quite harsh so the buttons/pcb moves or loosens a bit 🤷♂️
Someone commented it may be caused by the LED display which is Highley possible as its connected to the keyboard for key scanning and I would have given this a go but unfortunately this part is no longer available.
My brother works as a mobil tec for a well known white goods supplier and he recons that between 10 and 15% of faults are caused by firm ware
Its a big problem getting trying to decide if you have a hardware or software fault, I remember the very first software problem I had , it was an ITT Digi vision set with an east west fault , I replaced endless components to no avail , then rang ITT s technical department, the guy who answered the phone said straight away , change the Eeprom, I did that fault cured .
@@michaeldranfield7140 digivision became a swear word no one wanted to work on them one with a poor picture hung around for 4 weeks because of a faulty comb filter.
@@michaeldranfield7140 yep, bad software can make a device basically for the dump if you cant get a replacement eeprom or reprogram it, one time was a kenwood music system that just didnt work right, no part available, the other a vertical turntable sharp thing that'd drive the pickup arm off its end breaking parts, its cpu crashed instantly on power up!
Tell me about it, I have a Toshiba, Vestel set needs software and I can't find it anyware, I promised the old lady I would get her this set going again and it's been here over 2 months now.
Experiencing exactly the same issue with a barely used microwave of the same model. This is either a huge design flaw or a planned obsolescence feature triggering too soon.
,Some Sharp branded microwaves , £150 ish , no parts available, they are just considered disposable .
Hi Michael, I can't seem to find the video you made of a Samsung led tv with a panel fault. I think it was a similar tv to mine. I have a UA55NU7300K. I desperately need to chat to you regarding this but on UA-cam it's rather cumbersome
Hi Michael,
Could you recommend a supplier for replacement lcd panels for tvs please?
I get all my spares from ASWO in France, it's the only place left now.
Similar issue here on our mc28m6075. Started off with the top of the "third 8" on the display going.
Now the display is ok, but we've lost 1st, 3rd and 4th rows of buttons, as well as start/30sec and stop/eco buttons and child lock
For a 2.5 year old machine, its utter crap. Out of warranty and now needing to repair it or get a new one. But can't afford to repair this POS every 2 years.
Unfortunately everything you buy these days is crap, I did a video a while back on a sharp microwave, not a cheap one either, it cost about £150 to buy but was classified as no parts available so essentially just a disposable item.
Thank you for this video, have similar issue with this microwave, just other buttons, rest identical.
Whats the spare part you've bought? Is there any site where this spare parts can be purchased?
I got this from ASWO in France but you need to be an account holder , you should be able to find a replacement on the net by searching with the part number on the board .
That second button down "healthy cooking" which is something guaranteed not to happen if the food's come out of a microwave.
I have no idea what it does , no doubt just another gimmick load of old rubbish as you say .
😂 oxymoron
@@Stop..carry-on Lol yup, fake marketing at its best.
My microwave says "enjoy your meal" when its finished, again, with food out of a microwave this is highly unlikely.
😅
Hi Michael, excellent video. Would you have the reference part number of the new Board Control Panel you got for this Microwave Samsung MC32J7055CT? That's because I need to change mine. I would appreciate your response. Thank you.
I could get you the part number on if you send me another message on Monday , dont have it here as im at home now .
@@michaeldranfield7140 Certainly. Very kind of you! Thanks for your reply.
@@michaeldranfield7140 Hi Michael, my Samsung Smart Oven MC32J7055CT appears to have problems with Board Control Panel, like you showed in your video. Mine has lights inside, the digital clock works but the start button won't turn it on or even beep... I appreciate if you could let me know the part number so I can buy one. Thank you.
I have this issue on a similar model . It's the second time its failed and Samsung refuse to admit there is a design or parts quality issue.
you wont get Samsung to admit anything because there not bothered about customers any more , times have changed .
Doesn't look that old that microwave, were you able to return the incorrect part for credit? Otherwise you have another item to add to your vast spares stock
No returns on electronic items, this is just another item for stock, another item I may never use again!
@@michaeldranfield7140 sometimes I have returned items to Aswo and received credit for them ( as item no longer required or incorrect part ) obviously in a unused condition 😉
You could just have replaced the button from the board, and you would have seen that the button was not the issue. Or even swapped the button.
Just had a sharp which blew a display board after 2 years these things are built poorly
Sadly this is the way all electronic items have gone no matter how much you pay for something.
"Smart Microwave "😂😂😂
There is nothing smart about technology today
Bring back the 80s all is forgiven
Absolutley, everything was better in the 80s.
Ahh dam I really need to learn how to read and program these Ics, the issue is there’s so many different Ics to learn how to read. Had an Onkyo 838 with a bad hdmi board no hdmi working at all, replaced the hdmi Ic and the main out works. Just non of the in ports work, looking at the data sheet closer it appears the Ic is probably missing a set of instructions to communicate back to the mpu to get the input hdmis working. Ughhh couldn’t figure it out as ti licence the Ic to Onkyo there’s no info on programming 🥲
Clock crystal near by too ?