Time for New Solenoid

[Eric Christoffersen]

Machine is early B2 and has been doing really great for past 4 months but occasionally makes an awful racket.

I've mentioned it on here before but no one suggested anything. Searching there's mentions that fill solenoid can make this noise.

Was on vacation with machine, everything dandy and next day it won't heat. The steam boiler light isn't coming on. No voltage to pstat (supposed to be ac 30v?). That wire comes from control board so looks like I'll need a new one of those. In the past the control boards display strangeness but this one looks normal just no voltage out. This is a new control board as of last year, why would it fail just like that? Someone suggested that control board dying quickly will have another cause.

Looking on home-barista someone said when solenoid starts making a racket don't just replace the inductor (my name for the electrical part that wraps the shaft), that the insides are likely toast also. Could it be that my buzzing solenoid in some way cooked my control board?

I ordered new solenoid from wll. Here's pictures of my old one, a b2 original.

And a close up of the inside thingy that looks like it served a useful life:

Something else:

On vacation the machine tripped the gfi. I wasn't able to measure current to the ground so 'fixed' the problem by plugging into a non-gfi outlet. My home kitchen has no gfi so who knows how long its been like this.

Since gfi tripped instantly with cold machine can I conclude that it is the steam element that has failed? I literally replaced that element 4 months ago. Steam and brew elements both show 13.8ohms and I can't see any continuity from boiler to its power spades.

Ideas how to debug this?

[Eric Christoffersen]

Well... Installed new steam element, new solenoid, new gicar. Turn on machine and it fills steam tank quickly and stops. Its quieter than before.

And... still no steam heat light. Not seeing any voltage to the pstat.

I think next step is to take out the giemme board and check it. Never done that before.

[Eric Christoffersen]

And indeed its the giemme control board. The relay got stuck. I'm guessing this was caused by that rattling buzzing solenoid. I can't tell if its stuck open or closed.

Control board is NLA but I've got a friend with a solder station that can replace that relay.

[Eric Christoffersen]

Ok. Happy ending and some good stuff to share.

The relay on the board is a finder 44.62S, which was discontinued more than 10 years ago. Its improved replacement is the Finder 40.62.7.024.4000.

But that modern relay has also been discontinued for a while. They're available from places in UK and poland, to be shipped in 2023 and with exorbitant shipping prices.

I found one "new old stock" from radwell. $5 for the relay, then $15 service fee and $10 shipping.

Plan was to get my local phone repair store to replace the relay, but then what caused the relay to fail?

Luckily I came across "Boyt Enterprises", I emailed Mr Boyt and he explained it was probably a bad capacitor that caused the relay to be nuked.

I took it to Boyt who swapped the burned relay for my new one, he also replaced the capacitor with a new higher temp rated unit that should last 4x as long.

FWIW my capacitor had ZERO capacitance.

Understand... the control board receives AC signal. There's a diode that cuts off the bottom of that signal, then it goes to the capacitor that charges on positive signal, then discharges during the quiet time where the negative signal used to be, thus producing a sort of DC current. Well... when the capacitor has stopped working the downstream receives the signal from the diode, essentially a 60HZ ac signal. The relay gets this ac signal and fip-flops at 60 hz. The pump and steam fill solenoid received that 60 hz signal. Everyone is buzzing like crazy at 60 hz because they are getting turned on and off at 60 hz, instead of receiving a steady dc signal out of the capacitor.

The first thing to fail in my case was the relay on the control board, can see how its burned and the contact is actually welded in place for steam fill. When the relay got welded the control board could no longer switch from steam fill to steam heat, so filled and then just sat there. Worse would be if relay welded itself the other way, then I'd have power to steam element but tank not filled... there might be protection but maybe not.

So we're clear what is being discussed, here is my giemme control board. It lives just below my gicar pid.

Here is the control board with my new relay and Boyt's capacitor installed. He tested the transformer (brick on the left) and it was fine.

Top view:

Again. If your machine is making a horrible buzzing sound. STOP. Don't use it. Get that capacitor replaced or you'll burn out your relay. Capacitors are still easily available and are like 25 cents, and capacitors wear out. You can test your capacitor if your DMM has a capacitor test feature (mine doesn't.).

Boyt also said "Radwell is the worst place in the world to buy relays." He said he sources a better one that supports higher current and it costs him about $2 per.

End of the day:

Reassembled machine just now with repaired control board and... perfect. Steam fill is 'quiet' now and steam heat light came on as soon as fill completed.

[Tony Grant]

I have moved on from my Brewtus, but I’m still lurking on this group, because I love the tinker vibe, and just wanted to chime in to say that this is an absolutely stellar post. Great sleuthing, workarounds, and documentation! You will certainly save many people some time, money and heartache down the line. Bravo!

-tony

On Nov 3, 2022, at 4:01 PM, Eric Christoffersen <zak...@gmail.com> wrote:

Ok. Happy ending and some good stuff to share.

The relay on the board is a finder 44.62S, which was discontinued more than 10 years ago. Its improved replacement is the Finder 40.62.7.024.4000.

But that modern relay has also been discontinued for a while. They're available from places in UK and poland, to be shipped in 2023 and with exorbitant shipping prices.

I found one "new old stock" from radwell. $5 for the relay, then $15 service fee and $10 shipping.

Plan was to get my local phone repair store to replace the relay, but then what caused the relay to fail?

Luckily I came across "Boyt Enterprises", I emailed Mr Boyt and he explained it was probably a bad capacitor that caused the relay to be nuked.

I took it to Boyt who swapped the burned relay for my new one, he also replaced the capacitor with a new higher temp rated unit that should last 4x as long.

FWIW my capacitor had ZERO capacitance.

Understand... the control board receives AC signal. There's a diode that cuts off the bottom of that signal, then it goes to the capacitor that charges on positive signal, then discharges during the quiet time where the negative signal used to be, thus producing a sort of DC current. Well... when the capacitor has stopped working the downstream receives the signal from the diode, essentially a 60HZ ac signal. The relay gets this ac signal and fip-flops at 60 hz. The pump and steam fill solenoid received that 60 hz signal. Everyone is buzzing like crazy at 60 hz because they are getting turned on and off at 60 hz, instead of receiving a steady dc signal out of the capacitor.

The first thing to fail in my case was the relay on the control board, can see how its burned and the contact is actually welded in place for steam fill. When the relay got welded the control board could no longer switch from steam fill to steam heat, so filled and then just sat there. Worse would be if relay welded itself the other way, then I'd have power to steam element but tank not filled... there might be protection but maybe not.

So we're clear what is being discussed, here is my giemme control board. It lives just below my gicar pid.

<giemme3.jpg>

Here is the control board with my new relay and Boyt's capacitor installed. He tested the transformer (brick on the left) and it was fine.

<giemme2.jpg>

Top view:

<giemme_outside.jpg>

Again. If your machine is making a horrible buzzing sound. STOP. Don't use it. Get that capacitor replaced or you'll burn out your relay. Capacitors are still easily available and are like 25 cents, and capacitors wear out. You can test your capacitor if your DMM has a capacitor test feature (mine doesn't.).

Boyt also said "Radwell is the worst place in the world to buy relays." He said he sources a better one that supports higher current and it costs him about $2 per.

End of the day:

Reassembled machine just now with repaired control board and... perfect. Steam fill is 'quiet' now and steam heat light came on as soon as fill completed.

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<giemme2.jpg><giemme3.jpg><giemme_outside.jpg>

[Ken]

Great write up. I am thinking I should check that cap on mine. Is it difficult to separate the board from the plastic case of the giemme control module? Much easier to replace a bulging cap now than to source that relay! Mine is working perfectly but preventative is easier.

[Eric Christoffersen]

The board pulls right out of the plastic enclosure.

My cap wasn't bulging. Use your multimeter's capacitor test function. Its capacitance degrades over time. If its below spec replace it. Probably I will wait until symptoms before I replace it again. The symptom is an loud 60hz buzzing from machine - as if something was very wrong... :)

[Ira]

Hello Eric,

Saturday, November 26, 2022, 11:27:32 AM, you wrote:

The board pulls right out of the plastic enclosure.

My cap wasn't bulging. Use your multimeter's capacitor test function. Its capacitance degrades over time. If its below spec replace it. Probably I will wait until symptoms before I replace it again. The symptom is an loud 60hz buzzing from machine - as if something was very wrong... :)

In my experience I've seen more bad diode bridges than bad capacitors, though I always replace the capacitor with higher temperature ones. Stock is 85C I forget if the replacement part I use is 105C or 125C.

-- Ira

[Ken]

Do you recall the cap value? I would like to check my inventory or order before I tear into my working machine.

Thanks!

Ken

[Ira]

Hello Ken,

Sunday, November 27, 2022, 8:10:36 AM, you wrote:

Do you recall the cap value? I would like to check my inventory or order before I tear into my working machine.

The 2 parts I keep in my inventory are:

Diode bridge: W06GDI-ND  / W06G    600V 1.5A

Capacitor: 4486PHBK-ND  / MAL214650331E3  330uf  35V  125C

As I recall, there is not a lot of room for those parts so case size matters. Sometimes I've had to sand a flat on one side of the bridge to get them to fit, but I wanted the higher rated part. I also put the bridge up 1/2" off the board so the legs will act as heat sinks. Those are Digikey P/Ns

-- Ira

[Ira]

Hello Ken,

Sunday, November 27, 2022, 8:10:36 AM, you wrote:

Do you recall the cap value? I would like to check my inventory or order before I tear into my working machine.

Digging further I realize I also have some bridges from Mouser:  583-RC205 / RC205  2A 600V

-- Ira