Quote:
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Originally Posted by candido
I have a Tektronix TDS220 oscilloscope that has developed this
intermittent startup fault:
Sometimes when the power is switched on the LCD will only show a random
number of horizontal dark/brihter lines of random widths. The LCD
backlight will not be turned on and the mainborad doesn't appear to be
working as there will be no 1KHz/5V square wave on the compensation
probe output. .....
Tony
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Hi Tony
I would think you have an start up power supply failure rather than reset cycle at power up.
Have you located power supply values?. Normally they use 15v power supply connected to the battery board. Then multiple power values are generated by switching transformer.
I do also have a start-up problem with my TDS3014B, but it start backlight and actually the start screen is Ok. It pulses all front leds for a little bit and then the 1KHz/5V square wave becomes available. Start screen remains without change and there is no any diagnostic message. Troubleshooting chart doesn't cover this situation since it only is useful when diagnostic message apply. It seems to be a software problem rather than electronic problem.
Service from Tek is expensive. May you have to try all at your hand to sove yours...
I will aprreciate if somebody have an idea to solve this...
Regards
John_H