I've got a Harrison 4 series console that is equipped with 2 PSU's made up of PowerOne modules. The first is the audio PSU and has 2- 15A +15V/ -15V, a 5V,and 48V. The second supply is for the meters. A few months ago I had the -15V side go out, and I replaced the whole PowerOne module and now sometimes the -15 Voltage doesn't supply. The power connectors on the console channels are supplied via 6 pin molex connectors, that feed a motherboard for each group of 4 channels. I unplugged all of these to search for the culprit, and the -15V will supply fine. I proceeded to plug in these motherboard supply cables (with the psu off) and It will still work, until I get to around 8 or so (random) motherboards connected, and it doesn't supply voltage. I believe it isn't specific to a certain channel, or motherboard group of channels. I also have 2 extra Harrison audio PSU units for this board (1 spare 15A, and 1-9A from a separate parts console that I have) The 2-15A PSU's also contain what looks like an overload protection circuit and the 9A PSU doesn't. This behavior of not supplying the -15V happens on both of the 15A psu's (with the overload protection), but on the 9A psu it will turn on, supply -15V but buzz slightly and gets hot. I have turned on the console with 8 motherboards connected and hot plugged 2 more motherboards ( I know not ideal) and it works well all day with out any apparent issues using a 15A PSU. Something must be shorting out slightly somewhere. Would anyone have any suggestions of what to test here? Should I check current draw?
Thanks for any input.
Thanks for any input.
