Dear All
I wonder if anybody can help-
I have an appliance which runs off 240 vac. At its heart is a pcb which incorporates a transformer and associated circuitry to provide a 12vdc control voltage.
The machine has failed completely and i am being quoted the majority of the price of a new machine for a replacement pcb. Before I take this step I am wondering if it might be worth trying to replace selected components on the existing board in an effort to fix the problem. The symptoms are as follows-
The machine (a domestic appliance) failed mid cycle and appears to have gone completely dead- the lcd display and even the led "on" light do not operate. The 240 volt side seems ok but the 12vdc side is displaying particular symptoms which I am hoping might shed some light on which individual component on the board might have failed. When I measure across 12vdc terminals I get a continually repeatedly pulsing dc voltage which rises from 0 to about 2 volts in a (typically) 1/2 second period.
I am hoping that somebody out there might be able to link these symptoms to a particular component or component type within the 240ac to 12vdc conversion circuitry so that I can start by replacing these individual components in an effort to fix the problem.
I would be interested to hear any reservations which anybody might have about my proposed course of action (including advice for precautions) or of any alternative suggestons for fixing the problem e.g. fitting an ancillary 12v supply and disabling the existing on board unit.
I thank you in anticipation.
Gribbler
I wonder if anybody can help-
I have an appliance which runs off 240 vac. At its heart is a pcb which incorporates a transformer and associated circuitry to provide a 12vdc control voltage.
The machine has failed completely and i am being quoted the majority of the price of a new machine for a replacement pcb. Before I take this step I am wondering if it might be worth trying to replace selected components on the existing board in an effort to fix the problem. The symptoms are as follows-
The machine (a domestic appliance) failed mid cycle and appears to have gone completely dead- the lcd display and even the led "on" light do not operate. The 240 volt side seems ok but the 12vdc side is displaying particular symptoms which I am hoping might shed some light on which individual component on the board might have failed. When I measure across 12vdc terminals I get a continually repeatedly pulsing dc voltage which rises from 0 to about 2 volts in a (typically) 1/2 second period.
I am hoping that somebody out there might be able to link these symptoms to a particular component or component type within the 240ac to 12vdc conversion circuitry so that I can start by replacing these individual components in an effort to fix the problem.
I would be interested to hear any reservations which anybody might have about my proposed course of action (including advice for precautions) or of any alternative suggestons for fixing the problem e.g. fitting an ancillary 12v supply and disabling the existing on board unit.
I thank you in anticipation.
Gribbler