Power Supply Fan Spinning Slowly

The frequency is set by spinning generators inside power plants. Power supply system 48 V DC Power supply system Dewatering, Drainage and leakage collection system and their pumping arrangement. Also, this is a good example of the first principle of power – when you have power, always feign powerlessness. Helpful information and resources on Massey Ferguson tractors from SSB Tractor, a leading provider of tractor parts, manuals, implements and toys. The National Power Grid Electric power is produced by many independent power companies, including invest-owned, cooperative, municipal, and federal agencies. Agar aap ke computer ke power supply ke fan se aawaj aati he. A stand alone package of similar or superior power (except for being available inside the word processor) is Personal Bibliographic Software's Pro-Cite. BE PATIENT!. Attach the pulley removal tool to the pulley. The HH is really a FWD most of the time. I can clock it down to 1000/1100rpm but as the original fan seem to spin at 1800rpm i have set it to this speed. "I have to say, this thing is beautiful. When I sailed from Darwin to Bali I went farther north and avoided these. (similar to #19561). In these cases, the fan is spinning as fast as it can, but if the hot air is obstructed from reaching the outside world, a heat build-up occurs and the laptop takes the safety precaution of turning itself off, rather than allowing permanent damage to occur. Thanks in advance guys, please tell me if you want more information to better help any responses. Check the power supply. Don’t click back now – you’re about to witness the greatest catalog ever. With the cover still off, restore the AC power, start the computer and make sure the cpu fan spins - if it doesn't spin, if you're sure the power supply is working okay, don't use the computer until you have replaced it. 2 voltage but some power supplies will fail. Thrust is a useful indication of how much power the engine is putting into the fan, but it gives no indication about the uniformity and penetration capability of the wind stream. The engine’s 76- in. Against power outages, you’ll want an uninterruptible power supply. Servo motors have three wires: power, ground, and signal. Installed it just fine, LED green light comes on the mobo but the fan starts up for a few seconds then stops and the computer doesn't boot. How to Reduce Fan Noise in Windows 10 Computer. now there is a sort of fan (3 pin) connector as one of the cords coming out of the power supply, but I had that plugged in initially and the back fan still would not spin. 7kW Heating Capacity 50,000 BTU/h Refrigerant Type R-410A Heating Power Input 2. Computer power supply fan keeps speeding up and slowing down? I recently fixed an old computer and it was working fine for a month or so. If you are comfortable with taking the cooler apart to get at the fan, you can peel back the little sticker and put a drop of oil in the bearing. My monitoring software shows that my fans aren't spinning and I can't manually control them. They used paper / oil capacitor with separate aluminium foil as electrodes. The power wire is typically red, and should be connected to the 5V pin on the Arduino or Genuino board. - posted in Internal Hardware: Dell XPS 8910 Desktop computer Intel i7-6700 CPU 16GB DDR4 1TB HDD Nvidia GeForce GTX 750Ti 2GB. Most UPS devices only last a few minutes, but that should be enough time for you to issue a proper shutdown. The ground wire is typically black or brown and should be connected to a ground pin on the board. 1 to 2 or 3 to 4) and slowly raise the voltage until the motor is difficult to turn. From memory, that PSU has the 0RPM fan mode where the fan doesn't actually start to spin until the PSU itself reaches a specific load. My PSU fan is spinning too fast, it sounds like a jet engine. " The safest power supply is a Plug Pack (wall-wort, wall wart, wall cube, power brick, plug-in adapter, adapter block, domestic mains adapter, power adapter, or AC adapter). The analysis also shows the power supply itself is of shockingly low quality. I know for a fact that this particular PSU does not have some type of passive-fan feature where the fan stops during low-power usage, but the thing is PC still powers up fine and I've had no BSOD or freezes either. Now, I don’t think there’s any trick involved, there. It's making a little clicking noise inside the unit where you plug the power cord in. This is an online forum where professionals who work with Caterpillar equipment and engines can exchange information, find answers, and get expert advice from their peers. pdf), Text File (. When the fan was operating normally, the power supply temp reading would be normal - less than 40C. The hard drives don't start up, and the screen is black. Free delivery and return on eligible orders. Replace the system board. The maximum output voltage can be changed within the setting range. Its a wind-force card so it has 3 fans. Question: Why does the light on the ceiling fan not work? Answer: If the light on your ceiling fan won't work, it may just be a loose wire or a bad bulb. In this mode: Your console takes 45 seconds to start up. When the capacitor is called to action, it is supposed to release its energy and give the fan a sort of electrical kick in the pants. If your CPU fan does not spin, the issue could be anywhere from the fan, the motherboard, to the power supply unit. The one spinning a hand fan certainly doesn't. If you do see that your breaker has been tripped, it's best to call a trained professional to inspect your breaker box. The larger the duty cycle, the faster the fan spins. It's a 1000W G2 EVGA PSU. 90% of its propulsive power. Its a besta power supply at 500W. It'll be quiet and last a long time. Unplug the power supply, wait 30 seconds or so, and plug it back in, and the supply will be as good as new. It is pulsing on and off along with the clicking. Before inspection, shut off the power to the fan. Hello I just finished building my new PC about 2 weeks ago. not the +5V pin on your Arduino). - The bearing-mounted power handle enables drivers to steer softly when driving slowly and parking cars. Against power outages, you’ll want an uninterruptible power supply. The installation of electric vehicles For our nearly 500,000 alumni throughout the local newspaper select auto insurance quotes My first every claim that is another list of personal injury claim Mauris lorem, porttitor quis ipsum quis, vestibulum vulputate mi Hide caption 34 of bosque farms was arrested for possessing heroin and a 20yo daughter. The problem follows the psu. Power Supply: Rosewill Fortress 750w // EVGA NEX650G but will there be any issues besides the fan spinning slowly? B. 5v supply that you would never use, and that slowly damages the power supply over time. It can extract references from a text file prepared by Word Perfect and generate the appropriate reference list. Antec SmartPower 2. The only thing that has to be done, is to connect a resistor in series with the power supply of the fan. Listen for the sound of the fan spinning when the power is on What would happen if a PC that contains a power supply that does not. PWM is performed by the Arduino. Hence the reason for the power on. Not a big hardware person. Question: Why does the light on the ceiling fan not work? Answer: If the light on your ceiling fan won't work, it may just be a loose wire or a bad bulb. The danger is where stock is inserted, held and withdrawn, as with hydraulically or pneumatically powered shears. Powering a 12v fan via 5v USB. Which caused the blade to rattle and eventually stop. Well, that's enough of that. Is the "power good" signal coming up?. Sounds like the DC input on your laptop died and it switched over to running on battery. If you connect a 2Kw convector (not fan) heater in series with the saw it will limit the starting current and the saw will run up to peed slowly, if it's too slow use a bigger heater (3Kw). That is NOT your power supply fan. In this guide, we’ll show you where to find the Seaside Kingdom’s power moons. My car (A3 x reg) in the last few weeks has begun to make a squealing noise for a few seconds when it starts. ) as this will allow us to verify the device's functionality without needing it to be connected to any other components from your system. adsauthor "Yokoyama, Takaaki; Yokoyama, T. Check the circuit breaker or fuse that controls the power to the ceiling fan. Live is permanently connected. If the fan is not spinning like a mad man, it is defective(or the board is not giving it a high enough duty cycle). Now the outdoor fan will start briefly but the compressor does not. The graphics card fan is operational. This process is very slow, but necessary in order to correctly remove the power steering pulley. Every transformer varnish has a recommended drying temperature. Back at school, the team finds the spinning wheel back in the classroom, back to normal and in working condition. Be carefull not to break the fan. So solution: use a big fan, spinning relatively slowly. Its the loudest part in my computer. That is the fan connected to the "chasis power" fan header next to your CPU fan header. If you are comfortable with taking the cooler apart to get at the fan, you can peel back the little sticker and put a drop of oil in the bearing. PC Power and Cooling specializes in heavy-duty and quiet supplies; Astec has several heavy-duty models as well. NO NO NO! if the mac is overheating, there's a 99. Okay, coming again to this contribution from you on how to fix an electric fan, it is really well-done, and as I said, that you took the time and trouble to put it in the web for everyone to read and benefit from it, that is the proof that man is good, and one of man's goodness is the desire to share useful knowledge, and information of facts. I know that might be a big expense, and fans are cheap, but it's not worth the risk. The power wire is typically red, and should be connected to the 5V pin on the Arduino or Genuino board. ) So I was questioning could a defective fan burn out a power supply? That seems unlikely to me. Therefore, when flying for the first time, it should push remote control's right/left variable-speed joystick slowly, avoiding from collisions caused by rising aircraft rapidly. If the power supply fan does not spin or the LED does not illuminate (see Testing power supply ), replace the power supply. I see that your PCI ("Expansion slots") + PS ("Power supply") fans are spinning very fast. If the fan is not operating or is spinning very slowly, check all wiring connections and voltages to ensure that the replacement unit is receiving power. Remove the power supply and the fan of the ps. It's making a little clicking noise inside the unit where you plug the power cord in. Their program is interrupted by a news bulletin about the Power Rangers' recent win. If this happens, try testing your screen using the troubleshooting guides below. One of the first things you want to do when your air conditioning fan isn't spinning is to check the breaker to make sure it didn't get tripped. This, BIOS probably fail to monitor the CPU fan and consider it to be unworkable. From: Konstantin on 10/22/2003 I have replaced my PC's cpu fan with a Zalman cooler (model CNPS700-cU)(to reduce noise). Video Card Whine -- Fan or Power? not the power supply. " The safest power supply is a Plug Pack (wall-wort, wall wart, wall cube, power brick, plug-in adapter, adapter block, domestic mains adapter, power adapter, or AC adapter). If the fan on your unit starts to spin then your problem may vary well be with something else like the CMOS or the Power button on your case. - posted in Internal Hardware: Hi there!A few months ago my pc was conducting a windows registry update in which it failed. The power supply fan in my new XPS 8920 is not spinning up. I tried PWM fans (4 pins). Unfortunately, my power supply fan gave neither, so I picked one based on the wind output (felt by hand). First things first, make sure that you've got power getting to the fan itself. This process is very slow, but necessary in order to correctly remove the power steering pulley. Find Ecofan UltrAir Heat Powered Stove Fan, 810CAKBX in the Heating Replacement Parts category at Tractor Supply Co. When a power supply unit goes very bad, it might begin to expel smoke or emit a burning smell. They are not used for fan speed control. If they are correctly secured, unscrew them in order to remove the cover and check for any loose parts. Diagnosing a computer that won't boot can be very difficult. Every device in a PC requires a certain amount of wattage to function. Cases will vary, but normally you will see indicator lights come on and hear the fan spin with nothing appearing on the screen. In the online business world, some forward-looking companies have enlisted the participation of the “crowd. Video Card Whine -- Fan or Power? not the power supply. HP Omen - idle temps and fan noise The extra component causes the power supply to work harder and generate more heat. Running a tool's motor on 3-phase power means the output gets 3 "pushes" per revolution instead of just one. So can someone tell me if its safe to slow it down or will the power supply overheat. Is this a bad thing or does it just come on when it needs too?. ? it says my power supply's fan is only spinning at 672rpm. i have a new extreme power plus 550w psu and the fan doesnt spin. Makes Noise: If the pump motor makes a humming sound when trying to start, you likely have a bad start capacitor. When choosing parameters for the minimum and maximum fan speed, try to set them by hand (disable all the VARIATE FANs checkboxes) and listen to the noise. This isn't a problem by itself, but since vSphere color-codes servers according to their alerts, this means that my host goes red a lot, but I have to switch over to the alert screen to find out if it's just a slow fan or something more serious. A bit late to this, but to see what it was doing on my old system, The fan faced up and the power supply was on the bottom of the case so I just took off the side panel of the case and played some games to make it happen. I did notice that the fan for the hard drive is spinning slowly. Did the circuit breakers in the circuit breaker box (or electrical panel) trip to the OFF position? Check the SSU light switch on the gray box located at the furnace to make sure it is in the ON position. A hair dryer blowing in onto the tower's fan will cause it to run in reverse negatively discharging the built up or leftover engergy. A decent one costs around $150 and up plus they typically require a 12v power supply capable of a decent number of amps. I got one of these with my Cooler Master fan. Page 1 of 2 - How-To Quiet Noisy Case/PSU Fans - posted in Tips and Tricks: Do your case and/or PSU fans suddenly become noisy when you turn on your PC, then eventually quiet down, in most cases. Power Supplies. I would suggest turning. PC fans spin for half a second only, replaced motherboard and psu also. The big 140mm works fine. The PC seems to be running cool and doesn't exhibit any problems. UPDATE: Managed to connect two more fans to the PSU, they now spin at full speed, case is cool enough, but I'll probably buy a fan controller as advised, thanks for the help! Hi, I've been having some problems with my case fans spinning slowly. However, even with the hard disk powered down, the box drew almost 12W in sleep mode. Sun Fire V480 LEDs. If the blades aren’t turning or are turning very slowly, the fan has failed or is too clogged with dust to operate correctly. Following the replacement of the power supply, my computer now boots to the Windows 7 desktop in less than 1 minute. The capacitor(s) is located outside the motor housing, inside a hump-like metal cover. These power supplies often use larger-diameter fans that spin more slowly, so they run more quietly but move the same amount of air as the smaller fans. fix computer fan problem with noisy, jam, slow speed, and dirty in home clean fan and repair Computer Cpu FAN Repair in Home -Hindi Part-2 link https://youtu. If no power is reaching the time clock or switch, the tiny motor is dead, or the switch or breaker is bad, or the wires from the breaker to the time clock are broken or loose. Power of this aircraft is adequate. The processor fan is spinning. It has a 255 watt "80 I just purchased a Dell Optiplex 980 Minitower from an authorized refurbisher. The TFX power supply I was modding had some glue on the fan plug, making it hard to remove. Read honest and unbiased product reviews from our users. Warhead only competed in Season 5. This blue LED lights when it is safe to remove the power supply from the system. I purchased 3 of the same model 52011 Hunter ceiling fans last year and they have been installed for 15 months. Be sure to connect the grounds of the Arduino and external power supply together. In order to test your EVGA power supply, the first thing you will want to try is known as the jumper test (aka the PSU paper-clip test, jump starting, etc. not the +5V pin on your Arduino). 4-pin PWM fans and speed modification. Its the loudest part in my computer. EDIT: just checked, fan kicks in at 40% PSU load. Select System > Settings > Power & startup. Do not combine PWR01 and PWR02 PSUs in the same switch. Under maximum. Which caused the blade to rattle and eventually stop. Power Supply fan never spinning. The Rieter Manual of Spinning Vol. Page 5 ABG Heat Pump: Specifications HP50A/HP50HA - Specifications 14. ‎09-02-2017 11:15 AM Also, above top of motherboard (CPU and heat sink near top) is a little circuit board connected to the motherboard. Fan on motherboard spins for a few seconds then stops, no boot. Im using the h115i pro for my 8700k and ive noticed that the fans that came with the cooler (im using them as intake fans) are not spinning. There was (it seemed to me) fairly little > dust accumulation in the case and fans as I blew them off. I've built two nearly identical systems. replace the power supply because the fan will only slow down if the power supply has an eco mode but never shut down. The fan on the power supply is indeed spinning and this does not appear to be a problem of power supply, since the same power supply is working in another 410. A spinning wheel is a device for spinning thread or yarn from fibres. April 21, 2002 - by Mike Chin It's no news that power supply units are one of the major noise sources in a typical PC. The capacitor may have gone bad and therefore the fan won't start. This is weird, but all of a suddenly my MacBook Pro is running really hot and the fan keeps turning on. Everything is running. The case fan too. EVGA SuperNOVA 550 G3, 80 Plus Gold 550W, Fully Modular, Eco Mode with New HDB Fan, 7 Year Warranty, Includes Power ON Self Tester, Compact 150mm Size, Power Supply 220-G3-0550-Y1. Seasonic X-Series SS-460FL: 460 Watts of Fanless Power in the case a single large fan, spinning slowly, would all the system needs. All of the fans seem to go, except for one. The case fan too. The power supply fan comes full on when I turn on the box and never slows down. A capacitor stores power in a roll of electrically charged sheets of material. And screw the bolt up with washer to fix the both ring (a) and (b) securely. you should have at least one or two case fans even if there the general cheap $5 ones. Usually, it is contained within some form of housing or case. Graphics Card Fan spinning very fast but no display I got some case fans yesterday and installed them today, during the install i decided to clean my computer using compressed air can, used it before and no problems. Is there any way I can fix it? it. But in the case of the Ultra Low Power Energy Harvester design by [bobricius], the attached microcontroller doesn’t need to worry about managing power at all — as long as it can finish its job. getting one soon. Smaller fans have to spin faster and therefore die faster, and are much noisier. It has two fans in it. Also check for mung on the video card fan and heatsink if it has that, and the power supply's openings / fan. Once you have recorded the results you can move the fan to the next section and repeat the test for all 8 sections. Hello I just finished building my new PC about 2 weeks ago. We recommend that you immediately replace the Power supply. The motor power supply should be compatible with the DC motor. Burning Electric Smell, Power Supply Fan Not Spinning Hello, So my brother asked me to come over and investigate a smell coming from his computer, so I walked into the room where his PC is and immediately knew it was likely the power supply, as this has happened to me in the past. And I been trying to set it yo my liking. I recently upgraded my PC with a new GPU and more RAM. I have a OCZ 600W GameXStream Power Supply. This is accomplished very simply by altering the current flowing through the part of the circuit feeding the motor. HP 54502A repair once again - Page 1 -> The fan is slightly moving periodically but will not start spinning-> thers is a sounds like a power supply fault. Your main power connector on the motherboard could be defective, thus the main board is not able to detect the fan is working in the power supply. Check for any objects that might stop the fan. If you are using a laptop computer in your lap or on a cloth for an extended period of time, your computer may be overheating, causing the fan consistently run. You cannot use a resistance to slowly start a motor since the resistance reduces the torque of the motor then it cannot start slowly. it brakes). CPU and other fans - 5964538. First things first, make sure that you've got power getting to the fan itself. Less air is pushed through the hair dryer. It simply isn't drawing enough of a load to necessitate the usage of the fan during operation. Every transformer varnish has a recommended drying temperature. That is NOT your power supply fan. The larger the duty cycle, the faster the fan spins. Against power outages, you’ll want an uninterruptible power supply. Technology Soyo Raptor SY-PS400 switching power supply. (also using a PC fan spinning very slowly). Comparing to its resistance when cold, and considering the thermal coefficient of the resistance of copper, it's easy to calculate the internal temperature!. In power-saving mode, the fan stops spinning, and basically works pretty well. In typical operation, a fan often does not operate at all unless the thermal sensor of the motherboard detects heat temperature past a specific threshold value, and then the computer turns on fan until c. Makes Noise: If the pump motor makes a humming sound when trying to start, you likely have a bad start capacitor. Find Washing Machine Parts at RepairClinic. **Edit: I see that Ducane air handlers offer options including both electronic blower speed controls as well as constant torque (ECM) motors. It is possible to damage a motor this way, so don’t go too far. ‎09-02-2017 11:15 AM Also, above top of motherboard (CPU and heat sink near top) is a little circuit board connected to the motherboard. ? Does it mean i need the power supply is already defective and need to be replaced? btw it only boots up but does not load to windows and message appears " cpu overtemperature error, press 1 to resume. A differential-hybrid charge sensitive preamplifier (CSP) was designed by taking a monolithic dual N-Channel Junction Field-effect Transistor (JFET) and a high-speed, low-noise, operational amplifier as the core parts. I have a OCZ 600W GameXStream Power Supply. 16 thoughts on " Hacking Fan Speed on Dell PowerEdge Servers " kevin March 15, 2014 at 08:32. will occur, it is good practice to include guards with each and every fan. If the blade spins freely, turn the fan on and listen as the blade accelerates to full speed. The connection must be made for the exhaust fan to work. See the stock footage by Evolve from their Car Parts In Garage collection. Fixing Issues with System Resources. Even if you get the fan spinning this solution is only temporary. After testing the burst and idle speed apply a current to the heater and slowly increase the temperature of the. The cooling capacity is decided by the flow rate in CFM which is c ubic f eet of air moved per m inute (can be approximated by RPM) of the fan. If you suspect a bad capacitor, you can easily and cheaply replace it yourself. Optimization of spinning conditions plays a key role in the development of high performance asymmetric hollow fiber membranes. If you still have no lights, try connecting the power supply in a different outlet. This is a known issue with eMachines PC's. The Silverstone SX600 is said by some to be quieter but testing says otherwise. I can clock it down to 1000/1100rpm but as the original fan seem to spin at 1800rpm i have set it to this speed. Antec SmartPower 2. My ASUS rig has a few of these fans running using 5V for the fan speed setting. getting one soon. Free delivery and return on eligible orders. i dont have a graphics card hooked up yet. 5v supply that you would never use, and that slowly damages the power supply over time. If you have a 12V power supply you can connect a 24V fan and it will turn slowly and quietly. I had this exact problem yesterday where the CPU fan came on like a jet engine and the PC didn't start and the monmitor was blank. Do not pull or excessively bend the power cord. Same sensor is used, but at 95C, the fan must be at least slowly spinning. I have an old ocz mod X stream 700 that could run quieter than this thing can. But as soon as the computer is all loaded, they stop. If it’s a faulty PSU you may be able to service it. My PSU fan is spinning too fast, it sounds like a jet engine. Several LED status indicators on both the front and back panels provide general system status, alert you to system problems, and help you to determine the location of system faults. Advance Spinning Techniques Coarse Code: YM-4013 By Sohail AD 12-NTU-0024 National Textile University 2. Alternator Frequently Asked Questions. Failing power supplies are common and can cause your symptoms. everything but the cpu fan and main power, does. The fan in the picture linked is a 12 V, 1. The Startup tone sounds. 5v supply that you would never use, and that slowly damages the power supply over time. But when I turned it back on, I noticed my REAR CASE Liquid cooling fan wasn't spinning which probably made/makes one of the other fans spin faster to try and cool it down more, making the humming noise. There is a one switch on the north wall that gives all power to the fan and light. But that's not all. Was convinced it was the mobo so we bought a new one. 0 Exam Question-Answer dust from the power supply. will occur, it is good practice to include guards with each and every fan. April 21, 2002 - by Mike Chin It's no news that power supply units are one of the major noise sources in a typical PC. Just makes me a bit nervous. It also spins the power supply fan at max rpm it sounds like. Power Supply: HiPro I have just noticed that the fan on the power supply is not running, but do not know how long this has been the case. Motor characteristics are frequently given as two points on this graph: The stall torque,, represents the point on the graph at which the torque is a maximum, but the shaft is not rotating. Screen does not power up but fan and hard drive spinning. Unbalanced loads can be the result of a defective motor or unbalanced power supply. To ensure the loads can be satisfied. To get it right, I occassionally removed the power supply, and measured the resistance of the primary winding. Listen for the sound of the fan spinning when the power is on What would happen if a PC that contains a power supply that does not. So if your power supply fan is really starting / stopping or changing speeds that suggests the fan may be failing and the entire PSU will have to be replaced. The fan would fall short, even though it is a 950 CFM fan and could produce 1. The cpu fan, system fan, and PSU fan don't turn off. If that fails to do the trick, then replace the power supply, or the power supply fans. Some plug packs have a switchable output voltage: 3v, 6v, 7. (Other of the same type don't do this) Also when I use another psu in that case the case fan runs normal. Choose from original manufacturer parts or high-quality universal replacements. Everything seems to be running but you can’t see anything on the screen, not even a flashing cursor. My ENERMAX EG365P-VE has two fans (as you know) But I the bodem one spinns very slowly. Whenever I plug in my xbox to the power supply only the fan turns on but the power switch doesn't respond. Power Supply Unit Make, Model & Wattage The fan of the video card is not spinning. fan is about 11 in. Every time I start pc, it shuts down suddenly after several time and next time I restart it, a message appears saying "cpu was shutdown due to a thermal event - overheating. 2) Do you see any bulged capacitors as shown in the below hyperlink "Capacitors". Computer Freezes Large Spinning Icon YouTube might be running slowly because world wide web is very slow. The Zalman fan has been replaced by a three-speed Antec fan with a 4-pin power connector. Make sure the fan power cable is connected firmly to the motherboard. Page 1 of 2 - How-To Quiet Noisy Case/PSU Fans - posted in Tips and Tricks: Do your case and/or PSU fans suddenly become noisy when you turn on your PC, then eventually quiet down, in most cases. ∗4 The maximum output voltage does not exceed the power supply voltage. I chose to go with a non-pwm fan. The fan blade on my pc popped out of its ball bearing. However, even with the hard disk powered down, the box drew almost 12W in sleep mode. it will speed up for a few seconds, and then slow back down for a few seconds, then speed up for a few seconds, and slow back down for a few seconds. I have done some research and testing and the unit is getting 240v, the relays appear to be. Be careful not to let the air spin your current fans to fast when you do this. This, BIOS probably fail to monitor the CPU fan and consider it to be unworkable.