Under the Hood (Cont’d)
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A side view of one of the two modular +12V power supply boards and the primary section to the right, behind the fan. The two small blue pots (rear corner) are used to adjust the +12V over current and the +12V current-share settings at the factory. Under no circumstances should the end user change either of these two adjustments!
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Here you can see all the auxiliary circuits on the main PCB that generate the -12V, +3.3V and +5V outputs along with the independent 20W +5VSB section. The small blue pots at the top of the riser board are used to adjust the +3.3V and +5V output voltage regulators.
(click to enlarge)
(click to enlarge)
With the fan removed you can see the primary rectifier sandwiched between two aluminum heatsinks along with the associated primary chokes. This section supplies primary power to both modular power boards, which contain the secondary +12V circuits.
Two different thermistors are mounted on the main heatsinks to monitor internal component temperatures. They send signals to the fan speed and high temperature shutdown control circuits.
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Here is a close-up of the +3.3V and +5V voltage regulator riser board behind the -12V VRM heatsink. The +3.3V section is on the left and the +5V section is on the right (closest to rear wiring harness exit).
Hi and thanks for the great
Hi and thanks for the great write-up! Regarding the adjustments within the power supply, I am wondering what can be done to adjust the +12vdc? Thanks for your thoughts!