Sunbeam EM4800C repair

Kelsey

Thanks AM - I might just take you up on that. I'm heading down to Brisbane Friday to check out a couple of machines that might be in the budget, so I'll know what I'm doing early next week.

Kelsey

Thanks AM will do - and great info about the oil, I didn't know that.

UNM

FINALLY. I made some time this afternoon to work on the two old 4800C machines. to recap: Both got as freebies through CS Pay It Forward One with duff pump, other with dodgy p/f seal (new, but still not sealing right). replaced faulty pump and all was well with that EXCEPT steaming - pump didn't pulse and so steam ran out rather quickly. I figured I could fix the pump issue easily enough with a second machine to troubleshoot, but my initial suspicion of dodgy control board was proven false when I swapped the boards and fault stayed in the original machine. Issue shelved for some time due to silly season. Well after double checking the control board again today, I realised how completely stupid I had been. Ulka pumps require correct polarity. Normally, with an AC input for extractions the pumps run fine, but as the controller provides a pulsed DC output for steam, the pump will not work if wired the wrong way round. Dumb mistake on my part and I should have spotted it sooner. Now on to the other - simple matter of measuring with the micrometer to check if difference in collar or p/f clearances between the various parts.

UNM

Anger Management wrote:

All depends on the wiring.. Some do and some don't have a power diode in the loop. If you have a wire that goes through a little rectangle block and that is mounted into a little pocket (can also be free) on the pump housing and the other end to the pump. Then this is the diode :-) Not all systems use this and in some cases it is to force the pump to perform differently..

All four thermoblock systems I have opened up had a little pocket on the pump solenoid with a thermal cutout (Uchiya up72http://til.com.hk/Thermal%20Protector/up72.htm rather than a diode. The rectifier diode is built in to the pump. Pump even has a handy diode symbol printed between the two power connectors. I'd post pictures if I could While researching this, I found an interesting troubleshooting page, for a breville 800, but has some content useful for other machines, check http://siber-sonic.com/appliance/breville.html

UNM

AC/DC: Still not convinced. If it was AC, why would polarity be an issue? EDIT: if I get a chance, I'll work out what the controller circuit does and post an update, but don't hold your breath.

UNM

It is of course possible that we are both right in our own internal understanding of what is happening, but not explaining well enough for each other (and probably others) to grasp what we mean. If only I could post a few pictures... Maybe soon

UNM

Just for completeness: The other 4800 that I got from tango had a problem with the p/f not sealing unless the handle was pushed way across to the right. Couldn't see anything wrong with the group head seal or installation of the collar, but cleaned everything anyway and measured with digital calipers. I reckoned that the new collar on this unit was slightly deeper than the original (around 0.5mm give or take). Filed the lugs down a tad and it now locks perfectly, all tested and no leaks. Now to pass them on through 'Pay It Forward' on another forum as originally promised. Just need to get my account reactivated, or have someone else list them on my behalf.

Kelsey

I can do it if your account reactivation is unsuccessful.

Koffee_Kosmo

Pass it on/Pay It Forward is available on Crema KK

UNM

Koffee Kosmo wrote:

Pass it on/Pay It Forward is available on Crema KK

True, but I got them from that other place and said to the original owners I'd fix them up and pass them on in the same place. Only seems fair to follow through on the commitment. Other items are more likely to be listed here first.

UNM

Thanks for the offer to list them kelsey, but rather than cause any potential problems for you, I listed them myself.

Davelikescoffee

Hi all i'm new here just trying to see why the coffee machine i purchased for my girlfriend has starting making loud noises and not pumping properly. It hadn't been descaled in about a year so i thought this would be the problem. I tried to undo the screw to get the brew filter out but it was stuck and i rounded it. I thought i would take the machine apart and maybe i could get at it from another side, i was wrong. Inside i found a heap of crap that you can see in the picture. I presume this is a result of the old drip tray that rusted through due to it being the wrong type of metal. I had another attempt at removing the screw and it snapped, leaving half of it in the machine. Any suggestions.

Davelikescoffee

Thanks for your response anger management i appreciate it. I think i have managed to re-size the pics hopefully you can see them ok now. I really want to avoid having to buy another machine as we only just bought a new drip tray last week which cost $65 and i'm a struggling student(4th year electrical engineering). The scale in the pictures is underneath the tray section so it would have been caused by the dodgy old tray, so fingers crossed it looks worse than what would be inside the thermoblock. Further information that may help is that steam arm seems to work fine, its just the brewing that seems stuffed(not as much water is flowing and noisier like the pump isn't getting enough water). The only descaling was using some vinegar/water mix, i have never changed nor do i know what the group seal is. The machine does not get a lot of use maybe 3 or 4 cups of coffee a week.

derrilex

I reckon you would be better served by a manual coffee making device like a aeropress. For 4 cups a week its hardly worth turning it on. I would have thought being a student 3 or 4 per hour would be more like it :rofl:

UNM

whereabouts are you? Could be a duff pump - works ok without pressure, but unable to push against back pressure when brewing. can't quite see from the pics. Is the broken screw the one in the centre of the brew head? There are ways to remove screws, but you will need to have clear access so you can get to it. drilling the centre of the screw and using a hex key tapped info the drill hole sometimes works - also, as am says do it hot. I wouldn't waste time on the screw unless you know that everything else is fixed, because machine may not be worth fixing.

Davelikescoffee

derrilex wrote:

I reckon you would be better served by a manual coffee making device like a aeropress. For 4 cups a week its hardly worth turning it on. I would have thought being a student 3 or 4 per hour would be more like it :rofl:

Yeh during exam time it does get a bit more of a workout, but during normal semester i'm at uni everyday so the library serves a decent brew.

Davelikescoffee

UNM wrote:

whereabouts are you? Could be a duff pump - works ok without pressure, but unable to push against back pressure when brewing. can't quite see from the pics. Is the broken screw the one in the centre of the brew head? There are ways to remove screws, but you will need to have clear access so you can get to it. drilling the centre of the screw and using a hex key tapped info the drill hole sometimes works - also, as am says do it hot. I wouldn't waste time on the screw unless you know that everything else is fixed, because machine may not be worth fixing.

I'm in Perth, and yep its the screw in the middle of the brew head. Would it be worth me taking a video of it in operation, for you to look at?

Davelikescoffee

Anger Management wrote:

My gut says clogged ceramic switch plates and MAYBE partly clogged thermoblock. It uses the same path, just switches in the different thermostats for Brew Vs Steam. That being said any crap in the ceramic switch plates can cause a high back pressure... Thus pump will struggle / stall. Also steam will travel through the thermoblock, even when partly clogged; but water will not ... Thus pump will struggle / stall. As it is in bits... I would check the switch plates but take care !!!!!!! AND maybe as a first option; I would run a couple of descale runs but in steam mode and DO IT OUT SIDE... Especially if using a quality descaler... The descale may move clear the thermoblock if that is the problem and on the second hit; changing the switch over etc may move any crap if its in the switch plates... As the screw is broken deep in... It will be a pain.. Removal of head etc and drill it out / re tap and a new SS C/sunk screw. Lot of effort.... If you have the tools; worth a go. If having to PAY for it to be done... Go the upgrade path...

I put it all back together, yesterday and ran one lot of vinegar/water mix. After putting probably a litres of fluid through it i got a few speckles of contaminent but nothing to write home about. Will have another go on the weekend, are the tablets much different to cleaning vinegar(both are recommended in the sunbeam manual)

Mach1

G’day I have an EM4800 and given that I live in Oakleigh I wondered if you’d be willing to give me a hand working out how to unblock it (the pump is working but no water coming through) if we are not too far apart? I noticed you live in the SE so I hope you don’t mind me contacting you. I haven’t posted on thos before and couldn’t work out how to PM you. Best regards Mark

askthecoffeeguy

If the pump is working properly it could be a blocked water line you could try taking the brew head apart and seeing if there is a dissolved washer in there But really speaking that sounds like a job for a repairman all coffee equipment should be regularly checked and serviced at least once every two years as preventative maintenance can be a lot cheaper then the cost of repair

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