Hi, can someone point me in the direction for a schematic diagram for this single fan psu? Physically is looks perfect, no burnt, dark smelly components but it took a surge and now doesn't power up at all. Not sure if it is worth my time but I'm retired so!!!!
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Re: Logisys PS480D Power Supply is Dead
First of all you should check power cable of smps. if it is ok then you can check smps for ok or fault.Short green and black wire in main output connector(for motherboard).If fan dont moves then check primery rectifire(4 diodes),switching transistor and protestion transistor(on first heatsink),check fuse,ntc,capacitorin primary section. Hope this be of initial help/idea. Pls post back as requested, how things turned up or should you need additional information.
Good luck and kind regards.
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You mention '..info on BIOS..'
Is your BIOS (or anything) displaying on the screen?
If screen is also dead, then your PSU 5V (red) section is suspect.
As the fans are fanning then 12V DC (yellow) is still OK.
To check your PSU, unplug & disconnect all power connector cables (note where they go, esp the M/Board supply).
Some PSU's have a green 'signal good' wire which to test must be grounded with a paper-clip etc to black.
This tells the Power Supply Unit to start up.
Black is common negative, Yellow 12V positive, Red 5V positive.
I hope your test results are not too negative. ;)
Hope this helps.
The 300W Power Supply Unit is still somewhat under-powered 550W is required so that the computer is powered by a PSU working under minimum load strain and well within its power output capacity. 300W is the original Specification, See here:
Sometimes, positioning the base unit directly on a carpet with a thick shaggy pile, or enclosing in it, during use in a poorly ventilated under desk cubby hole, next to a radiator, or in place receiving direct sunlight, polarised by glass in the nearby windows or some similar place can have a underestimated impact on the base unit's ability to cool itself when in use. Cooling is essential for the CPU, Motherboard Chipset, Graphics Card or onboard Graphics Chip, Hard Drive and RAM Memory. All need to be as cool as possible to work at optimum efficiency and the performance of each suffers drastically when exposed to over hot conditions, particularly the CPU which, from stone cold, can reach the temperature of boiling water within seconds of the computer being powered up and will underperform, overheat and shut down at the merest incidence of over hot conditions. So review all the salient cooling issues, then consider adding a separate, dedicated, fan cooled graphics card, its GPU Fan adding to the efficient cross circulation of cooling air to more of the interior and, also, its own built-in GRAM freeing up the 16Mb, 32Mb, 128Mb or 256Mb of System RAM that the on-board graphics chip borrowed from the RAM Modules. RAM that has to work less hard, works at a cooler temperature and thus more efficiently. The CPU works more efficiently as it no longer has to compensate as much for the loss of System RAM previously commandeered by the on board graphics, so it also generates less heat in doing so. Consider removing the (usually) green coloured, plastic Heat Conduit over the CPU and changing the CPU Heat Sink for a more effective, higher quality one, the leaving the conduit to one side. Cooling is about the rapid movement of vast volumes of air. The conduit works against itself by unnecessarily confining the hottest component in the case - the CPU. See an example here:
Consider also Inexpensive but beneficial, cooling Motherboard Chip and RAM Heat Sinks for the RAM Modules. Inexpensive, underside fan powered Hard Drive Coolers that screw to the underside of Hard Drives. See examples here:
The 550W PSU is necessitated by the extra cooling devices you contemplate installing
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Unpower the unit and then take off the access side panel. While looking into the unit, put the power back on (plug it in, but DO NOT press the Power button yet). - LED's should light, but no fans should turn. Still looking at the fans - especially the CPU fan, press the Power button and if they twitch then your unit power supply has died.
If they spin for a few seconds then die, look at the capacitors by the memory - if they bulge and are 'wet' then the motherbioard has died - ask Dell for replacement! (This is common, but Dell will only recognise it at the point of walking into the court, then only if you sign a secrecy agreement/gagging order!).
The Logisys PS480D is a 480W ATX Power Supply for Intel P4 and AMD. You will find complete instructions posted here: http://www.fonerbooks.com/r_power.htm
This steps you through what you need to do.
Easiest thing to do would be to meter out your power connectors, and locate the various voltages that way. Use a multimeter that can read up to 20v DC, and go round the connectors. On most PSU's the black is negative, and the various colours represent the other voltages.
the caps dry out. look for bulging caps. you won't find a schematic for the ps boards. infocus had someone else make them. the problem seems more like a overheating issue. as for the other one with the "just the fans", check the colorwheel.
Getting a schematic is rather doubtful. You might be able to get a general idea of the circuit from somewhere on the 'net.
Was the power supply dead?
ATX style power supplies have both a standby and main section. The standby supplies a low current +5 volts to a small portion of the motherboard.
If the component failure is in this section, this standby voltage will be missing or incorrect, and the computer will be dead- won't power on at all.
I've seen a number of catastrophic failures in this standby circuit, and repair isn't suggested or economically feasible, especially as some parts often poof beyond identification.
When the pwr button is pushed, the main section comes on, and supplies +5 (Red wires), +12 (Yellow wires), +3.3 (Orange wires), -5, -12. Look here for this info http://pinouts.ru/Power/atx_v2_pinout.shtml
Voltages are precisely regulated, and any substantial deviation (more than a few 10ths of a volt) indicate a problem, especially on the +5 & +3.3 lines.
mtn texas , If you PSU cooling fan is not working it could be just the fan. However based on the other facts you have a failing power supply.. Its not dead completely yet but it will be. If you want to contact me direct my email is firstname.lastname@example.org... I am a certified Tech and run my own computer repiar business.