Case #1922 The Diamond Experience

Case #1922

Unit: Diamond TT550 585198

This was trial by fire. A lot of first things happened with this case. New machine, new supplier, new problem.

Let me give you the setting on this one. Customer bought this new dishwasher six month prior to this problem. The machine is an imported Italian dishwasher made by Colged. Good machine but a bit too fancy for the North American market. The customer's kitchen is so small that when the dishwasher door is opened there is no room to fart.

I had visited this customer on three earlier occasions for what seemed unrelated problems. First time, the machine did not drain. I found thick food stuff in the drain. The customer was not pre-rising the dishes for sure. Second visit, the rinse pump leaked. The mechanical seal failed on it. The distributor supplied me with a new pump and that was replaced. On my third visit, they had a similar problem to the first time. Because they were also using an old basket from an older machine, pieces of it, a peg blocked the drain.

Now here comes this case. The customer complained the unit would not work anymore, or work very erratically. After a few minutes, I found the electronic board had burnt connections on one of its terminals. I contacted the distributor’s support department and they provided me with a new board and no real explanation for the possible cause. Because the terminal was badly melted I improvised some connections on the new board. A week later they had the same problem. That's when things started to go bad. The distributor decided then to drop this dishwasher line, including warranty, tech support, everything. I tried at the time to plead this case with the factory in Italy directly and managed to get some technical help. They were not impressed with my improvised repair, blamed part of it and the other part they said that this kind of damage is likely cause by water.

Now I have a possible explanation for the problem but no one wants to pay for anything. Of course this dragged on for several months. I finally made an arrangement with the factory. They trained me. I received a lot of technical information. With all of this I offered to the customer to take the machine to my shop, fix it and bring it back. There would be no charge for any of it. Why? The way I saw it, it was an excellent occasion to learn, hands on, how this animal works. The reason for bringing to my shop was very obvious to me. In my shop I was able to literally strip it and study every component. Hopefully find if and where the water was coming from. I honestly thought the drain pump was drawing too much amperage. With all the crap it had to deal with, for me it was obvious.

On the bench, all the panels went. One by one, I check all the components for defect and damage starting with the drain pump. Well, it wasn't the drain pump. I looked everywhere for signs of water spots. I didn't see anything obvious. I only saw some traces from when the rinse-pump leaked.

I decided it's time for testing the machine with a new board. I was nervous because I didn't find the cause of my board failure. This time I changed for the proper connector (CN10) with the proper pins. For this test, the panel where all the components are is opened in order to see if something happens. Something did happen.

We turned on the unit. It did all the proper sequence for filling, temperatures all were okay. Through all of this I and my assistant are looking with a light for any signs of water leak or smoking wires but see none of it. Now it was time for trying the short wash cycle. This huge quantity of water shoots out from under the door, spraying all the electronics. Madly, we rushed to cut the power. Too late. Lost electronic board number 3. Well, you can imagine the mood I was in. Yes, I swore. More than once.

I realized a couple of things afterward. The customer never mentioned the fact the machine was spilling quite a bit of water. This, in sufficient quantities, can get to the electronic board underneath. It's so happened that the unit did not do this every time for them. It would happen on evening shift where the staff would use the dishwasher differently. I mean differently in a bad way. The day shift never had any problems with this unit only the evening.

It's not the first time that a customer does not tell me the whole story before I start. Anyway. I was left figuring out why that was happening. I knew for a fact that when the dishwasher was installed and first started it didn’t do this. It took me about a week before I finally contacted the factory and ask their opinion. The response was very quick and a bit surprising. They said it is the soft-start system that is blocked. "The what?”

During my training we covered the TT550 under-counter dishwasher quickly and focused on the TT750 hood machine. This was done mostly because they happened to have a TT750 but no TT550 handy for demonstration. There is no soft-start on the TT750. The soft-start system is a simple mechanism which allows the wash pump to draw air for a short period of time to dampen the full force of the wash pump. This is done with a small 1/4" tube connected to a small cylinder in the back of the machine. When the tube is blocked with crap, the wash pump deploys its full force and cause water to shoot out from under the door.

I took this system apart and cleaned it. It was indeed blocked. I put everything back. Put a new board. Covered it with a lot of plastic and started the machine. This time everything worked perfectly.

The machine was brought back to the customer. She told me that she would not let just anyone touch it. It's been working fine since.

Happy ending.