I thought I had an interesting fault when Mr Williams said his set would drop its colour during the advertisements but only on Channel 7. I could see all sorts of spin-offs to this. For years I had heard of boxes that would mute the sound for you during commercials – though I have never actually seen one. But if this set could turn its colour off, surely I could use the colour killer circuit to kill or even murder the sound during the ads!

Anyway, as luck would have it, Mr Williams didn’t quite mention that there were other problems with the picture on Channel 7. Most were due to a fine herringbone patterning on the screen from co-channel RF interference. Mr Williams lived in a block of units in a poor reception area and he had a Grundig Xedance 82 Flat and had a Panasonic NV-FJ620 VCR connected to it. The VCR was connected to the aerial and then onto the TV. The RF output channel had been set to UHF channel 37.

On the very crowded UHF band on the North Shore of Sydney, this is not a good choice. There are several channels available and I reset this one to channel 69 and hoped for the best. It fixed up the patterning but only long-term use will confirm my remedy.

Serviceman of the overflow

Thank God, I am not a plumber or a white goods technician – though it would be nice to get their remuneration. The very thought of sewage or rotten food stuck in pipes is all too much for me.

It does, therefore, do one’s soul good to be in their shoes even for just one job and it makes you appreciate your profession so much more.

Items Covered This Month Grundig Xedance 82 Flat AEG Favorite 675i dishwasher Sharp LC15AHIE LCD TV Telefunken SDX290H Philips 36PW9527/79R EM5A P/M

Mrs Serviceman is a formidable person and when she asked me to fix our dishwasher you just knew there was going to be no negotiation in the matter. This was a direct missive from on high.

The offending machine was an AEG Favorite 675i dishwasher that was intermittently dead. Basically the machine would start working perfectly, then after a while you could hear a small clunk and then the whirring sound of a motor. It was at this point that it would stop its washing cycle and the touchpad keyboard would jam up. In fact, you could not do anything for another 15 minutes or so when suddenly the motor would stop and the touchpad would start to work normally again. This cycle would be repeated every few days but the frequency was increasing.

I removed the covers and got down on my hands and knees and saw there was a tray underneath. In the centre of this tray there was a vertical shaft with a piece of foam on it. I worked out that this piece of foam would float on any water that was in the tray and as it rose, the foam would move up the shaft until it hit a microswitch at the top. This would then turn on a control solenoid and a pump motor which would empty the tray. This "flood control" was what was happening to this machine.

Not quite knowing what to expect, I concluded that this tray was for a safety overflow. But where was the water coming from? It certainly wasn’t pouring in but I did notice from the discoloured melamine on the righthand side that there was a water leak nearby.