AN ANCIENT WEGA REPAIR

Ive got a customer called Bruce, nothing unusual about that, except Bruce owns an ancient old Wega single group coffee machine that he just won’t throw out. Its a great old machine, but it leaks and its literally falling to pieces. So it turns up here when I have a massive work load and I can’t say no to Bruce. And the thing is really not what I want to be dealing with. But how hard can it be to repair?

Anyway this time the machine had power (power light is on) but wasn’t heating. About 3 years ago I replaced the element and the pressure switch. And both of these tested ok. This little Wega has a programmable touch pad to make one shot and two shot beverages, this touch pad was dead. Also removing the water level probe failed to start the pump, so it looked like the controller.

And sure enough when I finally got the controller out of the box, it was stuck in there and I had to cut it out, I found multiple components failed. This is why I am writing this one up. As these days getting a hold of controllers can be difficult. So below is a quick photo summary of the repair. As a spoiler once I had completed the repair and put the machine back together, it persisted with an annoying new fault. It would suddenly switch off the voltage to the element when it got hot. And would not heat again until it had cooled down. I suspected the pressure switch but after much swearing and wishing I could say in a nice way “Bruce please never bring your machine back”, I found it was fault of my own making. I swapped an EMI filter cap for one I thought was equivalent. So I removed the EMI cap and solved the problem. The thing worked, apart form the hissing from its leaks. No these leaks can’t be repaired, its cracked on the heat exchanger.

The damaged components are obvious
Replacing the 100 ohm power resistor, the transformer and the EMI capacitor
The 3 failed components replaced

How did I know it was those 3 components, well the Transformer was open circuit on the primary side, they always are. The resistor was blackened and the EMI cap had its stuffing blown out. Don’t worry too much about the EMI cap, I didn’t, I just found something similar and it caused an issue, so leave it out if in doubt. Its function is to stop the propagation of signals up the power wire nothing too important to us.

Finally in these old circuit boards its not a bad idea to replace the relays. I will list these transformers when I get them in stock. As they can be hard to find. Note I did not find precisely the same transformer, I over rated the amps.

Tools required other than a multimeter which is absolutely vital, soldering iron and solder sucker. Most of these board repairs are this simple. So don’t pay $300 for a new one, if you really want to get one from us here at Outwest for $200.

I hope this helps.

Stephen

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