Panasonic Bread Maker

[RandomGrinch]

The loaf was excellent! Now I am completely baffled as to what the failing capacitor was actually doing to affect the kneading. The motor ran and runs now making the same (offload) noises, and it was kneading - I looked. However, unarguably this loaf is far better than any of the recent ones even with their increased yeast and added white flour.

Hi,

There's a nice right up here, explaining the importance of start/run capacitors to AC motors :

https://blog.orientalmotor.com/what-does-a-capacitor-do

 

[motco]

Thanks RG, I was about to do a bit of self-education!

 

[motco]

Interesting! My only first hand knowledge of a.c. motors was at Hoover Ltd in the 1960s but those motors were field winding and armature types and the only capacitors were for suppressing interference. I can now see why loss of capacitance would have an adverse effect on torque. Thanks again RG.

 

[Jezy55]

I have a Panasonic SD 253



which after many years of only occasional use has ceased to 'bake' the dough on my usual choice of programme - the 5hr wholemeal option.

Initially I checked the element with a multimeter - it is showing 100 ohms, acceptable I'm told for a part which should show 104 ohms.

I've changed the thermal fuse but having run the rapid bake white option the dough is still not cooking - although it appeared to have risen well and the programme (and the wholemeal previously mentioned) has run for the set amount of time The existing element does not seem to be reaching a high enough temperature to bake the dough, but then again neither did a new replacement element.

In line with the train of thought on this thread I watched the paddle mixing the dough and the action seems more than acceptable; the drive belt is in not loose and turning the lower connector unit by hand results in some (expected) but not stiff resistance.

Both the strong white bread flour (Waitrose) and dried yeast are fresh.

I have no idea why the element does not seem to be reaching a high enough temperature to bake the dough. Does anyone have any suggestions please?

If the much discussed motor capacitor could be affecting the temperature of the element I am happy to have a go at changing this but could someone please point out where it is on the SD 253's circuit board (see photo)

 

[EightyTwo]

This board is different from the SD250. I don't see a motor capacitor in your photograph but the board looks a little cooked around the R4 resistor!

 

[motco]

The motor capacitor is unlikely to have a role in the heat cycle. If the element is getting hot, which I assume it is, then the thermostat may be at fault.

 

[Jezy55]

Thanks to both EightyTwo and Motco for your replies. I have now fully dismantled the bread maker and taken a clearer picture (attached) of the PCB - I think the grey box is the motor capacitor. The element is not getting hot enough so following Motco's train of thought I've looked at the manual

https://www.manualslib.com/manual/767201/Panasonic-Sd-253.html?page=23#manual

The only part I can identify, in my blissful ignorance, related to temperature control is the thermal fuse which I have replaced to no avail. Is there a component on the PCB which is a thermostat?

 

[motco]

The thermostat won't be on the pcb but will be connected back to it by a cable. Its function is to monitor the temperature in the cavity in which the baking pan sits so it will be a small device either inside or outside the metal wall - probably inside in the space between the wall of the cavity and the bread pan. The picture shows a feature in the cavity of my machine (different from yours) which is probably the sensor. It remains to be seen whether a spare is available though. It's the sausage shaped protuberance next to the screw head.

 

[motco]

Of course it could equally be the thermal fuse, I have no real idea. If you have already replaced the thermal fuse you'll know.

Immediately after removing a loaf from my machine I measured the temperature of the inner wall of the baking cavity with a non-contact IR thermometer. It was between 175º and 180ºC

 

[Jezy55]

I have previously replaced the thermal to no avail. The element was still bearable to touch by hand so definitely not getting hot enough (both the old and new element only reached this temp) and hence the under baked bread. So I'm currently stumped!

 

[motco]

The thermal fuse is just that, a fuse. It cuts the power to the heater in the event that the thermostat has failed to 'ON'. Whether the part I show in my picture is the 'stat sensor or the fuse I don't know. If it isn't then I cannot help further as my machine is different from yours anyway.

 

[Safety First]

I recently had similar problems with an SD257 and it became obvious that the motor was struggling to turn the blade and not kneading the dough properly. This was due to a faulty motor run capacitor. It cost less than £5 to fix.

If you are up to the task, and are OK with soldering, remove the hinge screw and take off the lid to make things easier.

Remove the 5 screws around the top of the baking tray and wriggle things around until you can remove the control panel section. Pull out the connections from the main pcb and set the panel aside, then remove the bezel.

Squeeze and remove the clamp around the mains cable so that it can be fed into the body freely.

Undo 4 screws holding the feet and remove the entire works, feeding the mains cable through as you do so.

Remove 1 screw and the plastic pcb cover. You will see a 450v 3uF capacitor on the board. If you can find a replacement with the right dimensions, just change it, but I found it was easier and cheaper to get a stud mounting motor run capacitor with flying leads. Drill a hole in the lower flange (clear of the motor!) to mount it and, after removing the old capacitor, run the leads up to the vacant holes in the pcb. Tie them in with the other wires and it all looks very neat.

Put it all back together again.

This!

Just bought a new capacitor and installed it. I have done the same on a juicer before but wasn't convinced it was the capacitor as it behaved differently to the juicers failure mode.
Juicer stopped entirely. Bread maker would growl and stop mixing, sounding like it was straining. The belt seemed to grip both wheels. No signs of belt crumbs. Both wheels span freely so went for the capacitor changeover.

It works fine now but we are running it at least 10 times under close supervision.

The next fail will be the inner metal skin rusting out. Tip- leave lid off so it dries out after a bake.

I got my capacitor from eBay. Sadly £10.
But pleased overall.

 

[motco]

I have previously replaced the thermal to no avail. The element was still bearable to touch by hand so definitely not getting hot enough (both the old and new element only reached this temp) and hence the under baked bread. So I'm currently stumped!

Unless you hail from the planet Zog, you won't be able to handle the baking pan during baking, let alone the element! You certainly have a temperature control issue. The only device that is likely to be attached to a surface that represents the baking temperature (>120ºC I estimate) is either the thermostat probe or the safety cut-out sensor and you know what the latter looks like so go for the other one if you can find it.

 

[motco]

Two years or so down the line here's hoping everyone here is well and enjoying their Panasonic SDxxxx breadmakers.
Mine has been steadily declining in performance over the past few weeks and so I decided to open it up and test the Ducati capacitor again. It was 2.8 microfarads when installed but now it measures at 2.3. Not a big drop but the decline is still in its early stages. Another capacitor will be obtained and fitted as soon as I can get one. I shall report back...

 

[motco]

I've ordered one from RS Components - more expensive but hopefully longer lasting. More anon...