Single Serve Coffee Forums

imecoli wrote:...Once again it started to act up again and I found this forum. I ordered a new pump and solenoid and put the umbrella Kcup over the pump. I just got done replacing the parts and it works fine once again. I decided to take the pump apart and post pics of the damage from water.

https://plus.google.com/photos/111064512197697768107/albums/5846908962198931057

^^^ Thanks, and welcome to you, too.

Hi,
Well I spent hours looking for a schematic for the b70. No luck at all until I found your post. I made the mistake (big mistake) of disconnecting three things from the board thinking that it would be easy to reconnect them from memory. (not) So after putting the connectors in there proper places I quickly powered on the b70 and got the bright blue screen again,,, Yea.


Am now starting the reassembly process. (replaced the air pump, transformer, and solenoid valve) I think I will try replacing the valve with the automotive check valve that others have done. It looks like a great solution to the "Achilles heel" problem.

Thanks again for the schematic, I have it in my file now.
Dan

Well my keurig B70 is finally reassembled and operational. I can tell you from personal experience that the machine acts really strange when you get the connectors for the solenoids backwards. Water comes out everywhere and the resettable fuse on the board also does it's thing.

Glad to hear you got yours working again, 44darkwing44! I agree, working without a schematic is grueling.

A while back I posted about my experiences while repairing my B66. My wife shared with a friend of hers that I was able to repair it, so this friend sent me a B70 to see if I could do anything with it. That’s OK, glad to help a friend. This B70 had the classic forward solenoid valve leakage, and the coil was completely open. Fortunately though, we caught it in time, because the leakage was not so bad that any real moisture leaked onto the air pump. Since I had gotten back into this again, and was going through this thread looking for disassembly instructions anyway, I thought it might be a nice idea to make a list of all the problems and causes I saw people discuss in this forum thread. It might be nice to gather them all into one place. I also did some experimenting with the unit, and came up with some more theories about how it operates. It is too much to list in one post, so I compiled all of this into two documents that are located here:

https://www.dropbox.com/s/k2pxxhdawc3g1xj/Keurig%20Problems%20and%20Causes.pdf?m
https://www.dropbox.com/s/18oru4uoyy72r18/Keurig%20Experiments.pdf?m

By all means, if anybody has any corrections or additions, I am glad to accept them. I didn’t start this thread, and the only reason I have been able to fix two units so far is because the way was paved by Switch998, who did start this thread originally, EmmJayEff, who got it to make sense, and countless other people who have contributed. Refer to EmmJayEff’s theory of operation and flow diagram to aid in understanding these.

At what point do you realize you are no longer troubleshooting, you are just playing?

Ha! Thanks very much.

First I want to thank the great folks on this forum thread who have 'worked over' their Keurig B70 (s) & shared their experience!
My son has a Keurig B70 that completly quit passing water, could hear some heating going on but no flow out - asked me if I would take a look at it (I am an electro-mech tech, about 30 yrs in semiconductor wafer fab equip maint & tend to tinker for 'fun'), which I was happy to do.
Found this forum/thread & was impressed with the quality & detail of posts & obvious capability of posters. Read 16 pages (at least twice), followed links & grabbed & printed the disassembly instructions, also the drilling for 'paper clip' top release instructions.
Finally got a circular 'tuit' & proceeded, so now I have a couple comments & additions (payback for help?).
Main 'fix' was a descale, at first got variable amounts of hot water out, continued, (also did a redundant unplug / reset) but continued vinegar soaks got it to give a consistent dispense ( did not experiment with different serving sizes).
But - having read about the problems with solenoid valves I decided to go ahead & open it up to check the innards, and there lies the tale...

I carefully measured per instructions & drilled 4 small holes and tried reaching in (confession - I had little faith in this working based on the mentioned amount of force required to unclip & my uncertianty re: exactly how the top hold on clips worked) but was unsuccessful. So went for the screwdriver method (removed bottom cover & base).
First Mod - Didn't like the bottom cover being riveted to the ground wires, drilled out rivet & replaced with machine screw & lockwasher & nut.

Even when I could see what I was doing & what was needed the paper clip straightened out without releasing the clip.
Note that the attachment clip system has a 'staple like' piece cast with the outer cover & the top clip hook (part of the top cover) faces inward, passing through the 'staple' & is quite stiff. I took the advice to bevel the hooks to about a 45 dergee angle - much better for future service.
Much Struggle & 2 breaks (1 top clip end & 1 'staple') later I got the top off. [Gotta be a better way]

For reference this unit has S/N 78.0000.0538410 on a sticker behind the drip basin & my son says it was bought somewhere around a year ago, perhaps from Costco, don't know what descale history may have been.

On This Unit - One of the measurements for the small holes is in error. Viewed from the back the right clip is 3 7/8 inches from the first hole, Not 4 1/8 inches from centerline - other than that & weakness of paper clip, great info.

I took the 'liberty' (especially with 2 now non functional clips) of enlarging the 2 previously drilled holes on the back & adding 2 sheet metal screws intention being to catch the hooks - but I may have missed, didn't double check as getting to where needed to end project.

Happily once inside I found a heat sink around the transformer & the later type (gray) & non leaky) solenoid valves - the innards were in good shape, reassembled & told my son

Told my son what I had done to it & that he now has a workable coffee maker again.

Had a hard time with registration, first (few) try(s) it wouldn't accept names from GMCR website!
I may or may not be back but I did want to leave compliments & a Thank You!

^^^ Welcome, and a thanks right back at ya!

I'm sorry if I missed this issue somewhere. My Keurig always loses its prime. I don't actually have to do anything to the bottom valve on the reservoir, just remove the reservoir and replace it. Then it usually primes. I wondered why there is an extra line to the water pump, looks like it just lets air into the pump, which doesn't help the prime any. I filled that line with water and clamped it off. Should be no air in the line, but it still loses prime. Doesn't make any sense. I was wondering if it might be some sensor or firmware issue. I ran the pump by itself and it works fine. Is the prime an air pump prime or a water pump prime? The air pump seems to working fine as well, although its a bit slow on large cups. It seems like something is keeping the pump from pumping even though there is water pooled up in the base under the reservoir. Very confusing.

Thanks for any feedback

I hadn’t checked this forum for a little while. Glad to see there are new visitors!

Atembedded – Check out the post at http://www.singleservecoffeeforums.com/dissassembly-repair-guide-keurig-b70-platinum-t8124-150.html#p92769, or just go to the end of page 10 and read Black Rose’s post, then on to the first few posts on page 11. EmmJayEff discusses the issue there. The bottom line is that you might consider that instead of having priming problem, the check valve that is in the line between the water pump and the hot water tank might be getting stuck closed and preventing water from filling the hot water tank inside. I also remember my B66 behaving that way, and I had to keep removing the outside reservoir and reseat it to get it to fill the inside tank again. What I remember doing to fix it was to clean out this check valve. I already had the unit apart, so I removed the water pump and disconnected it from the tube that leads to this check valve. I then took a long cleaning Q-tip and inserted it into this line and used it to clean the tiny bit of buildup out of the check valve (I think it came out vaguely green). If you have the bottom off of the unit you should be able to do this without disassembling the rest of the whole unit, since that would be a lot more involved than just removing the bottom. Of course, before doing any of this you should de-scale the unit with white vinegar, if you haven’t done that already. That process might remove the buildup in the check valve without going to the trouble of taking it apart.

Another thing I might mention is that I discovered that the plastic screen that is inside the external reservoir inlet seal is actually removable and cleanable, should there happen to be debris in it. I discovered this when I accidentally knocked it out of position. You can grab it by the + (cross shape in the middle) using a needlenose pliers and gently rock it out of position, then remove it and clean it. When reinserting it, it does need to be lined up exactly the way it was before, so make a note of how it was pointing.

As for the extra tube at the pump inlet that lets air in - since it is connected to the input side of the water pump, there should be suction present there, so I believe it’s purpose is to simply vacuum water out of the places where it shouldn’t be – like the aft solenoid valve and the air pump!

DM in AZ - For whatever reason, when I took my B66 and B70 apart, I didn’t want to drill into them to disassemble them. I used a very long, thin, regular bladed screwdriver to get to at least one of the top cover latches that were accessible through the bottom. However, I could push as hard as I could on the latch, but couldn’t disengage it. So instead I placed the corner of the machine that had that latch firmly on the workbench to brace it, lined up the screwdriver as before, and tapped the screwdriver handle moderately hard. With that, the latch actually released fairly easily (I had to pull on the cover at the same time to get it to separate though). After getting that first one loose, I was able to create enough gap in the cover that I could get the same screwdriver in through the gap, to access the rest of the latches and release them by tapping the screwdriver handle the same way. So for me, hammering did the trick – easier than pushing. Once inside, I also beveled the hooks to about a 45 degree angle like you did, because I didn’t want to go through all that again.

Thanks for the reply. Befor I saw the reply, I decided to change the fore and aft solenoid valves since I had a couple of tearouts I got from American Science and Surplus sciplus.com p/n 40672 3.25 ea. I bought them for something else but they are the same size and have same connections, even the same tubing left from the tearout! I wonder where they came from Anyway the unit seems to be doing fine now, no priming problems. I was going to put a water trap on both inlet lines but decided to try them out first. May do that later. Thanks to all who contributed to this great thread!

atembedded wrote:Anyway the unit seems to be doing fine now, no priming problems.

Glad to hear it. Welcome!

Mmmm... If the forward solenoid was stuck open during the tank filling stage, it might shunt the water from the water pump output back to the water pump input. This would make it hard to fill the hot water tank. In theory...

DM in AZ - Some of us would still like to find out where to get the improved versions of the valves. Sounds like you had one in the machine you took apart... You probably have the unit back together by now but if not, if you could tell us the brand name and part number on those valves, it could help some of us.

GetSet wrote:I hadn’t checked this forum for a little while. Glad to see there are new visitors!
DM in AZ - For whatever reason, when I took my B66 and B70 apart, I didn’t want to drill into them to disassemble them. I used a very long, thin, regular bladed screwdriver to get to at least one of the top cover latches that were accessible through the bottom. However, I could push as hard as I could on the latch, but couldn’t disengage it. So instead I placed the corner of the machine that had that latch firmly on the workbench to brace it, lined up the screwdriver as before, and tapped the screwdriver handle moderately hard. With that, the latch actually released fairly easily (I had to pull on the cover at the same time to get it to separate though). After getting that first one loose, I was able to create enough gap in the cover that I could get the same screwdriver in through the gap, to access the rest of the latches and release them by tapping the screwdriver handle the same way. So for me, hammering did the trick – easier than pushing. Once inside, I also beveled the hooks to about a 45 degree angle like you did, because I didn’t want to go through all that again.

I'm not sure how a plain ole' B60 related to a B66 and I've never dealt with a B70, myself, but I thought I'd chime in on the long slotted screwdriver technique for releasing the J hooks.

In the case of the B60, a long wide slotted screwdriver worked quite well for me. It was so long and thick that it was difficult to manoeuvre in the access channels but I was able to get the top of my B60 released in less than 5 minutes. I used a flashlight to help me see the J hooks. The length of the screwdriver made this rather difficult, however, because its handle was so large I couldn't get my eye lined up properly to see the hook. Using a very thick screwdriver blade did help, I think, because I was able to place it against the inner part of at least one of the hooks and simply twist it to release the hook.

In my case, with my B60, I didn't have to utilize the gap between the shroud and the top. I was able to reach all the hooks from the bottom.

I hope these notes help anyone else that may be trying to open their B60 without drilling holes.

- Tim

Like so many others, I learned the hard way that descaling the machine is the secret to getting it to work right. Mine was working fine from the repairs I made, but promptly started having priming problems again. I had some acid that was used for a stainless steel water distiller to descale it and decided to use that for the Keurig. It worked great. Now it seems like I have to do it every couple of weeks. Must be something in my water. The descaler is Lumen Cleaner & Descaler, single (6603) from http://www.purewaterinc.com.

Finally gave up on the Keurig. Just too much trouble. Found perfect alternative Hamilton Beach "Scoop" $59. Works perfectly (and pretty quickly) every time, no k-cup, pressurized water (you have to fill for each cup), but once you mark your measuring pitcher you get the same cup every time. Made a plexiglass scoop with my desired ground coffee amount. Overall I'd say the Keurig is simply a poor design and is only good for its parts.