Can anyone shed any light on this problem? If the relay is bad, is there a source for it?
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--- In TekScopes@..., "nielsentelecom@..." <nielsentelecom@...> wrote:
I picked up a Govliquidation Tek 2246 mod A. I am having an issue with channel 2 vertical deflection. It is off when compared to any other channel. When I have it on the calibrator terminal (1KHZ @.5VDC)it will indicate higher than normal about half the time I roll it thru the voltage range. I have done the bump test, and it will pop down to where it should be when it gets a smack on the side. I did remove the cover, and when I poked around the channel 2 vertical attenuator area, I found when I pull/push/tap on the K112 relay, I will get the level that is expected/manipulate the problem. I suspect a bad solder joint. I did get the service manual and read how the attenuator cascades. Below are the affected voltage settings. .1V and and 10 mV are not affected. 5mV and 2mv are tough to get on the scale so I did not test those reliably.
.1V and 10mV not affected.
.2V, .5V, 20mV, and 50mV are all affected.
5mV and 2mv not reliable enough for conclusion.
I did do the self calibration on the voltage section, and now the voltmeter is indicating a much higher than normal reading, where before the self calibration, it was measuring the correct voltage even if the waveform was higher than normal.
Is there any way to get to the backside of the main board where the vertical section is at without removing it? I see in the svc man that It involves gutting the machine for removal. I would prefer to leave the board in place and move around any solder joints and resolder it. Are these relays reliable? Since I was able to tap the relay as it was the most sensitive to the tap, I suspect that relay is either bad or not soldered in properly.
Nick
