Humbars on a Sony KV2702

Submitted By Member : Ultrascan

I was called to install a second hand satellite system, the customer had purchased from someone in India. At the time there was no sky TV, this is in the early days of INTELSAT and EUTELSAT. This was a 1.5 MTR dish with actuator and controller. It had been out in the weather for some time and it shows. However, I started to set the equipment up and discovered that the LNB was dead. This unit was the size of a tin of beans and told him that if he wanted a replacement they were at the time 200 pounds.

He was not best pleased and expected me to carry some of the cost. As I had not supplied any of the equipment, I felt he was taking the Michael. Well, he finally gave in, and paid for the replacement. It is not he could not afford it. He owns 34 chemists and many houses he rents out. This is where I get married to it. He would be on the phone every few days saying he has lines across the screen, and it is unwatchable.

I called round the next day and could not find anything wrong. Another day goes by, and he is back on the phone. I went round there again to no fault. I even bought the unit home and replaced all the capacitors in the power supply of the satellite receiver. There was no fault, and still he kept phoning. This went on for several months, coming into the winter. One evening I called in and sure enough he was right, there were thick horizontal bars across the screen. Now the room was dark wood and dimly lit. With a 60 watt bulb in a table lamp. I carefully removed the lid of the receiver so as not to disturb the fault. When suddenly the fault became much worse. I asked if someone had just turned something on, his wife said she had just started making dinner and had turned on the oven. I told her to turn it off and the fault started to clear.

It was at this point I measured the mains on the switch. And found it to be 190v, not believing this I thought I had measured it wrong, and asked for the oven to be turned on again, the voltage dropped to 176v.  I went to the van and bought in a variac that had a 20 % winding on and connected the table lamp. Set the voltage to 180v then to prove my point wound it up to 230v the room was very much brighter, and on connecting the satellite rx the humbars completely vanished.

I told him to get in touch with the electric company and tell them that he is not getting full mains. The man arrived as I was leaving, and I told him of the situation, I just said, so you think you know better. Oh well, he found out for himself. Later on a few weeks down the line. The electric company had to install a new transformer as he was on the end of an overhead power system. This involved planning permission and months of paperwork, but I never received any further calls. The Sony power supply did not show any faults with the low power, but as the sat rx was transformer fed, the regulators just were not working with low input.