Repeat performance 11/11/17, however the cause was not a blocked vent pipe. The DW flooded and the pump ran, but no water emptied. Removed the drain hose, but there was almost no flow. There is a NRV on the pump, so it wasn't possible to blow to clear the blockage, but careful sucking cleared it out.
After strip down, it turned out 2 cardamom pods had got past the filters and were blocking the pump inlet, and there was plenty of other gunk. The pods would not have caused the over flow, but is shows that large bits got past the mesh filter and blocked the outlet pipe, or possibly the impeller.
The bits get easily past the mesh filter when it's removed for cleaning. The filter mates with the base, so large parts on the pre-filter simply stay on the base, and never get cleaned out. When the filter is dropped back in, they can drop straight in to the pump. Cardamom pods swell nicely and block the small pipes.
23/1/23
DW started to fill then stopped. Lights still lit. Power cycle resulted in a crack, and no lights. I could smell the magic smoke. The circuit is easily removed. 4 screws (leave the central 2 in).
A LNK365PN from 2011 had a small crack and had 15R D to S. I only have LNK306 and they cannot provide the 1A the 365 can. A quick check and the ATMEGA 8L runs off 5V, and the pot div on FB pin has 2k/4k3 which works out to 5V with 1.65V on FB. The app note shows only isolated circuits, but this was wired with 320VDC onto pin D, then a choke wired D to S. The other weird thing was the -ve side of the input cap was wired to +5. I didnt track it as I didnt have the spare and the DW was full of stuff to wash. I took a 1A USB psu (repaired last month, not terribly good 4.6V and won't start if load > 0.8A) and wired that in instead.
I feel the choke configuration may have saved the electronics.
No comments:
Post a Comment