Bosh Dishwasher Board Repair

Bosch dishwasher CPU

Cyclone season is here and that means more fried Bosh Boards in Bosch Dishwashers. After an electrical storm here on the Sunshine Coast, I usually get a couple of calls about Bosch Dishwashers no longer working.

A quick inspection reveals the primary side of the power supply on the control board has been fried, occasionally outputs are effected. See photo.

 

Replacement Bosch boards have a retail price of more than $400, even to trade they are over $300. So in many cases my customers are throwing out the dishwasher. Even with insurance, the excess is still over $500.

Many Bosh boards are repairable, however the components are hard to find, some not being available here in Australia. Until now, I have sourced the main components that fry in electrical surges. In cases where the PCB tracks are not damaged it is viable to repair the board.

This is what we are offering. If you find your Bosh dishwasher is not working after an electrical storm you have 3 choices.  1. Call the Tech and be prepared to pay $500 bucks to have him/her fit a new board.  2. Throw out the dishwasher and get a new one $700, only $500 if you have insurance. 3. Remove the old board and send me a photo of the damage. If it looks repairable send it to us. We will repair it and send it back for $100. If we can not fix it we will write a report for you $45.00 stating that its stuffed for insurance purposes.

Removing the board from a Bosch Dishwasher is simple. Unplug the dishwasher, slide it out. Remove the lid (see youtube) and the right hand side panel. You will find at the bottom the board enclosed in a white plastic case. Some models may differ. Photograph where the connections go as you will forget where they go back, yes you will.
Remove the board from the case and send us the photos at info@tech-fix.com.au. We want to see any obvious signs of damage, if the PCB tracks are sizzled, its too hard.

Now i hear you saying but what if its not the control board that fried, it could be just a fuse. Now there is a good idea, but Bosh have no power filters or fuses in between the Control Board and the main inlet, thats why the boards fry. It could be the secondary board thats effected, but its not likely. If a power surge is the cause then its likely the main board is effected. Usually damage is absolutely obvious. I usually find that there is no voltage at the power switch, thats a sure indication the power supply on the board is damaged.

Yes I will look at boards from other brands, but I may have to chase parts which slows the process down. If it takes longer than a week, nagging from the trouble and strife will probably mean you will buy a new one. Unless you do the dishes for the week.

bosh cpu

 

Dishwasher not draining – warning beware of glass in drain pump

Just a quick note here to highlight a common cause of dishwashers not draining. A Bribie Island resident called us out as their Delonghi Diswaher was leaking all over the kitchen. It had made such a mess it had damaged the carpet. Should they get a new one was the question?
I ran the dishwasher up and found it was filling to the correct level but not draining, it would then attempt to fill again and cause a flood. On emptying the sump and flipping it on it’s back, I found this in the drainage pump. A shaft of glass, nicely impinging on the impeller. Apparently the night before the flood somebody broke a glass in the dishwasher and forgot to clean it up.
It had found its way past the filter and into the drain pump.
The moral of the story. Delonghi are great dishwashers but if you break glass in it,  take the time to carefully clean it out. Glass often finds its way to the drain pump.

glass in dishwasher drain pump

 

Cashflow 690 Battery Replacement

The Cashflow 690 coinmech, often known as the Mars 690 or MEI Cashflow has a 3V lithium battery CR-2430. These backup batteries are used to store user settings in the SRAM. They are not rechargeable, so need replacing when flat.

lithium 3v battery in a cashflow 690 coin mech
backup battery in 690 mech

A flat battery, usually less than a volt in my experience, will cause the mech to display “Low Battery” on the lcd. You can also enter the service mode and scroll through to errors and it will state “battery not ok” . Hold the yellow key for 1.5 seconds to access the service menu.
A flat battery is not a major problem in that the mech can still read coins etc, however coins may be inhibited and worse the batteries leak. A leaking lithium battery damages the surrounding components and turns a small problem into a big one. I am finding about 50% of the mars 690 mechs coming to me have leaking batteries. Usually the Vendor pulls the mech and leaves it sitting around on the workshop floor for a year. Its not until a mech is needed that they think about repair.

leaking lithium battery
leaking lithium battery
damage to cashflow 690
damage to components caused by leaking lithium battery

Removing a battery takes some skill as they are soldered to the PCB in three places. Like most things in life there is a right way and a wrong way to do it. We know the right way and avoid damaging any surrounding components or the solder pads. TechFix offer this service for $45, including the battery. Its best to send mechs in groups to keep the freight costs down.

battery removed from 690 mech
battery removed the correct way
new battery installed in Mars 690

 

Is it economical to repair an electronic control board?

Delonghi Control Board

This is a good question considering we live in a throw away economy. To answer this question I need to ask 4 more?

  1. Are replacement boards available?
  2. How much is a replacement board?
  3. How damaged is the original board?
  4. Can TechFix repair it?

In our modern economy, many mass produced electronic products can be purchased very cheaply even if parts are not available. So obviously equipment like printers, led power supplies etc etc are no longer worth repairing. Just buy another one.
However other commercial machines like vending and coffee machines, forklifts, Gym equipment, medical power supplies, air conditioning units, inverters etc etc are often expensive, as are their replacement parts. And in many cases some are obsolete so new parts are no longer in production. This is where our repair service can save you hundreds.

As a rule of thumb, if a replacement electronic board or the equipment itself is more than $200, then repair of the control or power board is a cost effective option.
The next point to consider is how damaged is the board. If it is a Triac on a Delonghi Coffee Machine board then the replacement component is less than $2 with an added 1 hour labour to diagnose, repair and test. So the control board is repaired for less than $70. And often we will remove components like capacitors that fail testing and replace them with better quality ones. We can also re-solder dry joints. So the board is better than new. Refurbishing inverters etc is a very cost effective exercise.


If the PCB board and tracks have been extensively damaged by salt water or lightening etc then a cost effective repair may not be possible. My technicians can assist with determining if a board is beyond repair.
Finally some faults can prove difficult to diagnose and/or we may be unable to obtain replacement components. This again renders a electronoc control board as throw away.
Sometimes we can obtain a schematic or a functioning board. This assists greatly in locating the fault. Some boards we see frequently and we know the fault even before we un-box it. In this case the repair is easy and quick. The good news is we only charge for successful repairs, so if my team fail to repair a board you send us, you are only out of pocket the postage cost.

So in summary, if a replacement electronic circuit board is costly or non existent and the original board is not extensively physically damaged. Its worth sending it to us for an evaluation.