Post By noidle22
Post By TampIt
EM6910 control panel lights will not come on!
Ouch, that means no coffee today, unless of course someone on here knows what the fix for this is.
And of course if I can fix it without taking it the repair man!~!
Everything had been working fine, the machine is clicking away as normal, heating etc.
The Power light is green and flashing, when you activate it, it goes from flashing slowly to flashing quickly.
But the rest of the lights do not come on.
I have turned it on and off a few times to try and "wake it up" but I suspect something up with the control board.
Any pointers very much appreciated, before withdrawal symptoms set it!~!
Withdrawal was setting in so I had to press my old campervan unit, a Breville Bar Vista into action.
Crisis averted, but no go on the 6910 yet - am I impatient - of course, this is coffee time!
Last edited by rawill; 30th December 2013 at 06:30 AM.
Interesting, after I posted I found the much earlier thread on what seems like exactly the same issue.
However, I decided to try the cleaning programme.
That is working fine, so I am starting to think there might be a dodgy temperature sensor somewhere.
And I went through and was able to set all the programmable settings, so again I figure it is a failed sensor or similar.
Last edited by rawill; 30th December 2013 at 08:03 AM.
Aha - all lights back on now.
It was not a sensor, but a blown thermal cut out (fuse).
$45.00 at the local repair agents and it is all good.
Most problems like these tend to stem from a faulty control board. I had a 6910 the other day that had the same symptoms as yours.
If it just keeps flashing but doesn't turn on properly it generally means the control board is receiving insufficient feedback from a part of the machine and wont turn on. In the case of the machine I had, the steam thermoblock wasn't heating so the thermistor on the thermoblock wasn't giving the right response to the board to indicate the thermoblock is up to temperature thus the machine just keps trying to heat up.
A simple way to check if one of the themoblocks is the problem, switch the machine on and let it run for 30 seconds or so the feel the shower screen. If it's hot then the group thermoblock is ok. You'll then need to check the steam thermoblock. Open the back cover and remove the screws holding the plastic cover over the back of the machine. Once removed you'll be able to see the steam thermoblock, just behind on the right of the pump. MAKE SURE the machine is off and unplugged as you don't want to be fiddling around live electricity.
Reach in and lightly touch the steam thermoblock, it should be pretty hot if it's working properly. If it's not hot at all then there's a problem there.
You can check the thermoblock element with a multimeter set on ohms, you should see around 40-50 ohms if I remember correctly. If you get a reading like this, it can be assumed the thermoblock is ok. (You'll need to remove the top cover for this test).
Also check the thermal fuse attached to the thermoblock, its the small white button looking thing with 2 wires coming out of it. It should be closed circuit. With a multimeter set on ohms, it should read the same or very close to the same as what is read when you touch both multimeter probes together, basically a closed circuit. If you get an open circuit reading, the thermal fuse has blown and will need to be replaced. If it blows again soon after replacement, it can be assumed there's something defective in the steam thermoblock and it will need to be replaced.
You can also check the steam thermoblock thermistor to make sure it isn't open circuit or in some other way defective and not sending the right values to the board. The thermistor Is the small orange button thing with 2 white wires coming out of it. Remove the bracket holding the thermistor in place and remove the thermistor. Trace the wiring and unplug it from the control board. Then with you multimeter set on ohms, connect the probes to the plug that you removed from the board. At room temperature it's about 90 ohms I think.
Then get a radiant heat source and heat up the thermistor. If it's working, the value on the multimeter will start to drop. Once the heat source is removed, the resistance will stabilise and gradully start to increase again. The thermistor is ok if these tests show this.
The control board is the problem if all these tests are positive. If the steam thermoblock is working when you first test it then it can be assumed that the control board is at fault anyway.
+1 for all that.
Originally Posted by noidle22
One minor addition, I ran into one erratic 6910 where the main thermostat was intermittent - took a bit of tracing. It would work (mostly) then fail just often enough to be a pain (according to the friend that owned it). According to a local repairer, that is not too rare.
Thank you guys, what great info.
I will wait to see how it performs with the new thermal cutout.
And I will keep this thread bookmarked.
My second hand EM6910 is doing this. Does this mean the control board is on the way out?
Originally Posted by TampIt
I'm guessing the original owner probably sold it because issues were beginning. When we first got it, it had the flashing light problem when it started up and the group head thermoblock worked but the steam one didn't. That happened on about the 5th cup we made. Then it was ok. But gradually it has gotten worse and worse to the point now where sometimes neither work, the light just doesn't stop flashing. The next day though, after a couple of on/offs it may work fine, both thermoblocks or just the grouphead, then the next day it craps itself again.
So what does it cost to get the control board replaced? Any chance my electrician brother could work it out (he's not a repair man)? We bought the machine for only $93 and hoping not to pay too much to fix it (it also needs a need group head collar which I'll attempt to fix myself). Money is tight here at the moment so if it's going to cost a lot we may have to kiss the espresso goodbye and drink plunger or, gulp, instant.
Thanks for any forthcoming advice. Cheers.
Originally Posted by ErinMor
Before you pull the machine apart, most secondhand 6910's I have encountered have been filthy beyond all sanity. A thorough clean (say using white vinegar as per manual) may fix it for you. Bad news: it will take a lot of water to flush it out afterwards. I find I can still taste / smell the stuff after 4 litres. Until the water from the group is drinkable, keep flushing!
The thermostat is a cheap ($5?) part at the top front right hand corner. Major surgery to get at, so a bill of about $75 from (SB warranty repairers in Hilton, West Oz) was about right if you are not into pulling stuff apart. Of course, it could be the control board, however apart from flooding / drowning they tend to be OK.
The service manual link is http://coffeesnobs.com.au/brewing-eq...tml#post493973.
Good luck, hopefully you can enjoy a few more cuppas from it.
Thank you, TampIt.
When I said 'control board' I meant the... like... motherboard part. Sorry, excuse my ignorance. I'm pretty clueless.
I'll do the white vinegar thing tonight.... if it is functioning for me tonight, that is!
Thanks for the info - just to be clear I think your measurements might be out. For instance the thermistor rating is ~100k ohms right? not just 90?
Originally Posted by noidle22
Given this can you confirm exactly what you meant for the steam thermoblock - I've just replaced the thermistor thinking I had located a failed one, but in fact the original was working the same as the new replacement (87k), now I'm wondering if the thermoblock itself is the problem...
I apologise, I wrote that reply many years ago when I knew very little about the Sunbeam machines. I don't know why i wrote so much when it could have been simplified.
Originally Posted by rh2600
To correct my errors, the "white button thing" is the thermostat which only activates if the thermal fuse for some reason doesn't blow. Sometimes they can be faulty and intermittently go open circuit.
Yes, the thermistor is around 90-100k at room temperature.
The thermal fuse is in the white tube mounted to the side of the thermoblock with blue wires coming out of either end. This is the most common failure.
If the thermal fuse, thermostat and thermoblock element are ok, it may be the thermoblock control relay on the PCB not switching on. This will necessitate a PCB replacement as the relay can't be readily sourced. I've searched for them but haven't been able to find a supplier.
Another thing to check, your machine is an EM6910 and not an EM7000 right? The EM7000 commonly shorts the steam thermoblock relay which can also blow the thermoblock fuse.
I wrote a reply outlining the repair here: http://coffeesnobs.com.au/brewing-eq...ing-water.html