Hi Tom,
If both SMPS boards are removed and you get a near 0 ohm resistance from VDD to GND, that¡¯s your problem. ?Now the trick is to find where it¡¯s shorted. ?Unfortunately it is most likely in the cpu. ?You can verify that by measuring resistance from VDD to ground at all the places that VDD exists on the board. ?The lowest resistance is your culprit. ?Many ohm meters aren¡¯t precise enough to do this. ?I use a milli-ohm meter to do this diagnosis.
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73
Jeff Moore
W1NC
