What is the difference between AT and ATX power supplies?

AT power scheme is the original power scheme that most of the older computers used. AT-style computer cases had a power button that is directly connected to the system computer power supply. Pushing the power button kills all the power instantly (whether the Operating System is ready for it or not!)


An ATX power supply is typically controlled by an electronic switch. Instead of a hard switch at the main power input, the power button on an ATX system is a sensor input monitored by the computer. ATX systems allow the Operating System to control the final “off” signal to the power supply; this gives the OS time to save all information and complete important tasks before turning off the power supply using a dedicated output signal (PS_ON#). ATX power supplies also support lower power modes. They have an additional “Standby” power output (5VSB) that stays on to power standby devices whenever the system goes into low-power mode.


The ATX specification is the newer and more power efficient design. It is superior to the AT power supply scheme, and is used on almost all modern desktop and laptop computers. ADL Embedded Solutions offers PC/104 power supplies that support the ATX power scheme with 5V, 12V and 5VSB outputs only. Although the full ATX specification has additional voltages (12V, -5V and 3.3V), these extra power inputs are intended for Desktop systems; most embedded systems have no use for these extra voltage inputs and so they are omitted to save power and space.

 For power rating of each connection, please see below.



How to fix the error Download file now SEND RFU UPGRADE

the error “send RFU upgrade makes the printer goes into a loop which would make most people stuck. Here are a few tips for you

HP Laserjet CP3505nThe quick fix (quick for you since you’re reading this article) for a cryptic error message for the HP Color Laserjet CP3505n printer.

Hello friends, Once stuck with this error, the printer goes into a loop which would make most people tear their hair out. In fact, some even buy a replacement and written the thing off for the scrap heap before anyone is even was aware of it. But I digress.

Here is what might help:

  1. Turn the printer on and then plug into the USB port
  2. Add the printer using an HP driver such as the HP Laserjet 4100 PCL 5 (make sure you name the printer “Hewlett-PackardHP LaserJet USB Upgrade”   **note the exact string includes no space between Packard and HP**
  3. Run the firmware upgrade utility and select that printer from the dropdown. It should run the upgrade no problem.

Before I hit on that combo I tried a couple other solution suggestions from partial info on various websites. If the above doesn’t work for you then feel free to try them as well. This includes:

http://www.vanguardsys.com/whmcs/knowledgebase.php?action=displayarticle&id=216 The fix in the first paragraph threw me because it sounded so good but just didn’t work for me despite multiple tries. My solution above is actually a much stripped-down version of the text that follows that first section…follow it if you want/need a step-by-step.

http://www.printerhacks.com/fixing-the-dreaded-rfu-load-errorsend-rfu-upgrade-on-cp3505-using-a-mac/ This appears to be a good solution for MAC judging by the high # of comments praising the writer. If you have a mac then you can try this and it likely will work for you (modifying it for the Vista PC I was on did not work for me at all.)