The IIcx, IIci and Quadra 700 have a common PSU. They therefore have faults in common. 'Soft power' (active power control) on from the keyboard switch requires the presence of a 5V TRKL ('trickle') supply in the PSU. Soft power off needs that the TRKL voltage fall to <1V when Shut Down is invoked from the Menu or the keyboard. Auto-start/restart rests with the adjustable rear switch. In how many ways can all of this go wrong? You are just now discovering the answer to that question.

TRKL is probably the commonest villain, especially with Astec PSUs. Do a search in these forums for 'Astec' and 'IIci', and 'Delta' and 'IIci' to get the gen. Sheeting home the blame to the PSU, however, relies on the assurance that the MLB is good, so make sure of that first.

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