Moles connector problem, they do not last at the currents they were being used at in this application. Replace both the PCB header and the one on the cable.?
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On Nov 26, 2018, at 12:31 AM, Raymond Boute <
Raymond.Boute@...> wrote:
My HP3586A suddenly lost its 5 V, with neither red nor green 5 V led on the A80 board.
I traced the?problem to overheating pins in the connector between the transformer and the A99 motherboard (burn marks around the pins).
Wiggling the connector reestablished 5 V, but the overheating is nearly immediate and severe . It does not occur in standby, nor do the connector pins on the A80 board show any overheating when the unit is on.? One would expect the current limiter to cut in if there were a short on the bus.?The rectifier diodes also get very hot. Evidently?troubleshooting cannot last more than a few seconds at a time lest the connector is destroyed.
Questions: (a) is this a known issue, (b) what is the normal current drawn from the 5 V supply, (c) might the rectifier diodes be switching improperly (e.g., causing shorts at switchover), (c) would replacing them by Schottky diodes be indicated?
