My PC won't boot up if the hub is already switched...

My PC won't boot up if the hub is already switched on. It gets as far as the desktop image and freezes up, [the icons never appear]. The only way I can get it to work is by removing the yellow plug from the hub after powering off the PC, and reinserting the yellow plug after the icons have appeared following the next PC boot-up.
I recently swopped over to BT and have been using the BT Hub for nearly two months.
I first mentioned the problem to this forum in September, but have not solved it yet.
Thought it worth enquiring if anybody has heard anything new about this problem.

Ribblelancs
The last, and only time, I saw that problem was with a friend's computer, and by a process of elimination the hub ethernet connection (i.e. the interface to the hub) was found to be faulty. I tried connecting to an alternative socket on the hub, but the result was the same. The only plausible reason is that the pc cannot complete its' boot up until the ethernet connection is established. I replaced the hub with a spare. Have you tried to connect wirelessly?
Have you tried to connect wirelessly?
No. My pc has not got wireless.
I replaced the hub with a spare.
And that solved it? Possibly that’s the solution here too, it’s my first BT Hub and it might be best if I send it back. Not much else it can be.

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Ribblelancs
The last, and only time, I saw that problem was with a friend's computer, and by a process of elimination the hub ethernet connection (i.e. the interface to the hub) was found to be faulty. I tried connecting to an alternative socket on the hub, but the result was the same. The only plausible reason is that the pc cannot complete its' boot up until the ethernet connection is established. I replaced the hub with a spare. Have you tried to connect wirelessly?
Have you tried to connect wirelessly?
No. My pc has not got wireless.
I replaced the hub with a spare.
And that solved it? Possibly that’s the solution here too, it’s my first BT Hub and it might be best if I send it back. Not much else it can be.

I've recently update to Yosemite, ever since my Mac won't boot up from the grey screen

ive recently update to Yosemite, ever since my Mac won't boot up from the grey screen, I've checked on the utilities and disk can not be repaired. I'm gutted is it dead?.........how can I solve this......help please
<Re-Titled By Host>

Did you mean Command + Option + R for internet recovery?
The only key commands I know that involve P is a PRAM reset:
https://support.apple.com/kb/PH11243?viewlocale=en_US&locale=en_US
Or maybe I am missing or misunderstanding something?

My iMac won't boot up past the white screen with a grey apple and spinning icon

My iMac won't boot up past the white screen with a grey apple and spinning icon...please help!

command R did not result in anything different - still the white screen, etc. I do you Time Machine with and external hard drive, but I unplugged that. I have the installation DVD, but it doesn't seem to be reading it either.

EliteBook 8760w won't boot out of the box

As stated, this notebook won't boot out of the box. I get a screen that reads " Phillips windows 7 64bit image"
The below, there a boc to rnter a computer name and to search AD or a abort button.
I've run all the diagnostics and they are fine. I try to tap into f11 and I get a screen flash and then it goes back to starting windows and the usual Phiilps screen. I'm thinking just a bad image and a lemon from the factory.
Does anyone have an answer for me?
Thanks
-Thor

For fastest resolution contact HP Support via Chat or Phone. Choose your country here> Contact HP
******Clicking the Thumbs-Up button is a way to say -Thanks!.******
**Click Accept as Solution on a Reply that solves your issue to help others**

Repairing laptops that won't boot and show the blinking caps

Here's a little tutorial for all of you who have this annoying issue. It mostly applies to the 1 blink code (other codes have much simpler and straightforward solutions).
Ok, so the code says that it's caused because of a not functional CPU. That is most likely not the case. Most people who had the 1 blink code actually had a problem with the integrated video graphics card or northbridge of their laptops, not the CPU (in fact, CPU failures are quite uncommon). The problem is that these chips overheat quite often, they don't have good cooling and dissipation systems (most of the time, it is shared with the CPU which is absolutely insane), and the solder connections are of very bad quality. So with overheating, solder points start fracturing or cracking and they stop making contact, which causes all these issues, including the infamous RRoD and YLoD issues in the Xbox and Playstation consoles with their soldered video chips.
So there are two main ways of dealing with this:
1 - Reflow
This is a short-term but easy solution that simply consists of reheating the damaged component to the point of getting rid of said fractures. It has a high success rate, as many people will tell you. It worked for me always, but again, after some time the issue may come back. Still, this is a very simple solution that doesn't require too much skill or equipment and is satisfying enough for most users. This is what I'm going to show how to do in this tutorial.
2 - Reball
Reflowing doesn't always work, and when it does, it doesn't last long. Instead, reballing is a permanent solution which consists of removing the chip in its entirety and replacing all the solder contacts. Reballing requires specific equipment (a reball station), reballing stencils and leaded solder balls. It is a long procedure, which requires some skill and it only should be performed by experienced people. When a reflow won't work, you are better off sending your laptop to a reballing technician, or buying a new one (which would be a waste, in my opinion).
Ok, so how can we do a reflow? There are many ways to do this:
1) Reheating your laptop: This is a simple as it sounds. Some people call it the "blanket" method, because you can just simply turn on your laptop, wrap it with a blanket or sweater and let it run until it shuts down because of overheating. I absolutely don't recommend doing this, as there are probably many working components (particularly the hard drive holding your data) that won't benefit from the overheating. I recommend disassembling the laptop and taking out all the good parts, like the hard drive, RAM sticks and any extra PCI-e cards installed. After that you can just simply unplug the cooling fan connector from the board then turn the laptop on. This will cause it to overheat faster, so you won't have to waste hours waiting for it to get hot (using the blanket method, it can take a lot of time). Most laptops will shutdown themselves after reaching a certain threshold temperature, if yours doesn't, well, just keep an eye on it so you can turn it off before it catches fire. After it turns off, let it rest and cool for at least an hour, then connect the cooling fan again, turn the laptop on and see if it boots. If it doesn't, well, you can keep trying this until it does (not recommended after 3 tries or so), or try the next methods.
2) The oven method: This a bit tricky, but it may be more successful in some cases. First, strip down your computer until you get to the bare board holding the video chip. Remove the CPU, heatsink & fan, RAM, BIOS battery, wires, speakers, stickers, plastic sticky guards, foam spacers, absolutely everything that can be removed from the motherboard. Then preheat your household oven to approximately 200°C or 385°F. If your oven does not have a digital temperature display, perhaps use an internal oven thermometer to make sure the oven is in the right temperature range. Roll up some kitchen foil into balls, between half an inch and an inch wide, and place them on a baking tray. Place your motherboard, with CPU socket and GPU facing upwards, on top of the foil balls. It is a good idea to wrap additional foil around the more sensitive parts of the motherboard, like areas where there are capacitors and the CPU socket.
Try to wrap the rest of the motherboard in foil to protect it, leaving just the GPU exposed on both the top and bottom of the motherboard. Then place the baking tray with the laptop motherboard on it into the preheated oven.
Make sure your kitchen is well ventilated at this stage, turn on the extractor fan to full power and/or open an outside door and windows. This will help to take away any fumes. Ideally, you should leave the kitchen while any fumes are still present. A couple of times during the procedure, have a quick look through the oven door (without opening it) making sure there are no smoke or flames visible. This is unlikely to occur, but can happen if stickers were left on the motherboard. After 8 minutes, turn the oven off and open the oven door. Do not remove the motherboard from the oven at this stage, it could be very hot and it is a better idea to allow it to cool down gradually. Take care not to inhale any fumes that might be present. After 20 minutes to half an hour, remove the cool motherboard from the oven and begin rebuilding your laptop. If all has gone well, it will boot up and the problem will be fixed. If the problem remains, you could try the procedure again, leaving it in the oven for a couple of minutes longer.
After performing a reflow in an oven, I recommend cleaning the oven thoroughly, then turn it on and allow any fumes that may have built up to be completely removed. This is especially important before cooking food in the oven again.
3) The heat gun method: Probably the best way to do a reflow, it is less destructive than the previous method (as you can focus on a single place, rather than overheating the entire board), but it may be worse than the first. The first step is to test out how well your heat gun will melt the solder. Place a chunk of solder on a coin, hold the heat gun one inch above it and record how long it takes the solder to flow. Once you have the timing right, mask off the motherboard (already removed from the case) so that just the chip in question is accessible. Reflow with the same spacing and timing as you did during the coin test.
Did it work?
If your laptop works now, then you can do a couple of extra things to avoid this problem in the future:
Avoid overheating by underclocking the CPU: You can run your laptop's CPU at a lower clock speed (it will run slower, BUT not as much as you think. Undercloking by a 50% doesn't mean your laptop will perform 50% slower). It not only protects your laptop from damaging over time, it has the added benefits of making it run *much* cooler and quieter and also having longer battery life, which is awesome as well. To do this, simply (in Windows 7 and up) click the battery icon in your notification area, select More power options, then change the selected plan (like Balanced) settings (click on Change plan settings), select Change advanced power settings, scroll down and, under Processor power management, Maximum processor state, type on both 'On Battery' and 'Plugged in' a value less than 50%. Change Minimum processor state to 1% and then System cooling policy to Active.
Avoid playing heavy games and running intensive applications: Such programs very often cause the underpowered integrated graphics card and CPU to overheat, which causes all these issues. Use a desktop machine with dedicated graphics for such programs if you want your laptop to last.
Again, always take out the hard drive before any of these procedures if you don't wanna lose any data, and if you can, any other components that can get damaged in the way. Note that a reflow, particularly the oven or heat gun methods are usually last-ditch resorts because they can permanently damage your computer, in particular if performed incorrectly. DO IT AT YOUR OWN RISK. I can't be held responsible for any accidents or unwanted results that may occur after following this tutorial. If you have doubts, then you're generally better off sending your laptop to professional technicians than trying to repair these kind of issues by yourself. Unless a repair costs more than replacing your laptop, that is.
And before starting any of these procedures, try to research your issue on the Internet as much as you can. Search for your particular model, search in this exact same forum and any other as you'll be able to read about people experiencing this problem. You can search reflow on your favorite search engine and you'll find detailed tutorials and many videos which will show the procedure and help you do a better repair. Once you're very comfortable and knowledgeable with the subject, you can go ahead with the repair.

This is actually good stuff and well written but I hesitate to advise people to use either the "oven trick" or really even the heat gun method as both are notriously short-lived even if they appear effective. Your far better bet is to send the board in to one of the vendors on the internet who are set up to do a proper reball. Even those fixes are good for maybe 12-18 mos. But again, you get a high grade for spelling it out.

How do I back up my MacBook Pro from an external hard drive if my macbook won't boot up from the white start up screen? HELP!

I went to the Genius Bar a week ago, and the guy helping me there was nice enough to help me save some money by telling me I could replace the bad hard drive my MacBook Pro had by myself. I bought everything I needed (hard drive, screws, external hard drive) and my computer won't boot past the white start up screen. It doesn't even show the Apple sign at the start up screen. How do I back up my computer so I can save all my music, school files, etc.? Could really use someone's advice on what to do! Thanks!

Ok, to be sure I understand what's going on. You were able to boot the Macbook from the existing "damaged" internal drive, and it has been backed up to the internal.
If that is correct, your internal drive is working. Just to be sure, try booting with the R key down. Then run Disk Utility to repair the internal drive. That drive may in fact be useable.
You should be aware that you cannot boot the MBP from a Time Machine back up.
Please post back so I am sure I am understanding the situation.

My 27" iMac (2009) won't boot OSX from the internal drive

Here's a fun problem. After installing Sophos anti-virus and starting a (VERY slow) full scan, a day or two later I found my iMac frozen at the screensaver. It was completely unresponsive so I did a hard reboot, at which point it got as far as starting to boot Lion (apple logo on screen, spinning indicator showing) before stalling indefinitely in that state with the indicator spinning.
I restarted and booted from the recovery partition, launched disk utility, and discovered that the SMART status of the drive was "failing". The machine would still boot from the recovery partition and my boot camp partition, but I assumed that the disk failing was why the OSX partition wouldn't boot (the recovery partition worked, as did the windows 7 bootcamp partition). I replaced the factory-installed internal HDD with another of the same make, model, and capacity (Seagate 1TB), and performed a restore from the Time Machine backup on my Drobo.
The result was the same as the original problem - it wouldn't boot, hung with the indicator spinning. Thinking that the Sophos scan was somehow responsible (in-progress when the last TM backup was made) I tried restoring to a backup a few days older, (to the best of my recall from BEFORE I downloaded Sophos) only to have the same result.
Anyone have any ideas? I made a clean install of Lion (using the recovery partition on my old internal HDD, now connected externally via USB) to an external drive while I was waiting for the replacement hard disk to arrive, and it boots fine from that. I haven't tried a clean install to the internal HDD yet, as I'd obviously prefer to recover my installed apps as they were before, that being the point of a Time Machine backup, right?

You have a serious drive issue that likely can't be repaired that way.
Follow the data recovery efforts here, your drive still works and thus data can be recovered, won't be easy
https://discussions.apple.com/docs/DOC-3172
If you have your data off the machine, to a storage drive (or earlier with TM)
then hold command r keys and use Disk Utility to Erase the Lion Partiton with Zero option, and reinstall Lion from Apple's servers.
use the same name (important), different password ok Software Update fully
install your programs from fresh orignal sources and return files into their respective folders
once your stable, read the backup proceedures here etc.
https://discussions.apple.com/docs/DOC-3045
https://discussions.apple.com/community/notebooks/macbook_pro?view=documents
note, don't move your computer while it's operating

MacBook won't boot - stuck showing the Apple logo and the spinning circle.

Hi.
My MacBook suddenly froze when I was using it today. Displaying the spinning beach ball.
It never came out of it, fan running at max speed, so I tried to force restart it (Control-Command-Power), but that didn't work, so I forced the MacBook off (holding the power button pressed.)
When trying to start the MacBook again it couldn't boot. It kept displaying the grey screen, with the Apple logo and the spinning circle below the Apple logo.
I left the MacBook like this for 10-15 minutes, but nothing happened.
Went on to try the following.:
*- Removed the AC-adapter and battery for 5 minutes.*
*- Command-Option-P-R (Resetting PRAM and NVRAM).*
*- Resetting System Management Controller (SMC).*
*- Command-S (singleuser boot)*
And checking the HDD with sbin/fsck -fy
= "The volume ** appears to be OK."
*- Command-V*
Stops on the following line, and fan ramps up to full speed.:
DNSServiceRegister("ssh.tcp."): -65537)
Force reboot didn't work. Had to force it off.
But, nothing helped.
It simply won't boot.
I also tried to boot Ubuntu 7.10, but it hangs after a short while displaying "Kernel panic".
Force reboot didn't work. Had to force it off.
Also tried the option to boot from the first HDD (in the boot menu on the Ubuntu 7.10 disc), but that didn't work either. Only got a black screen, with a blinking cursor top left, and fan ramping up to max.
Again, force reboot didn't work. Had to force it off.
The only thing that has worked so far is exiting the Ubuntu 7.10 CD boot menu, and pressing enter on the prompt that appears.
But, after rebooting, the MacBook still refuses to boot into Mac OS X.
I left the MacBook alone, hoping it would work its way out of the spinning circle, but after 2 h 38 min nothing had happened.
Does anyone know how to fix this?
:. nattugglan

This happened to me last night.
I was updating my iPod and I got a message saying that it needed to do an update. I installed the update and went on ahead putting new songs on my iPod. When it was finished i ejected as I usually do and closed down.
When I went to check me e-mails this morning the Macbook would not boot. It sticks on the grey screen with the Apple and the spinny disc underneath, then it restarts and sticks on the same screen. The last software to be onstalled was Norton 11 on Monday but I have used the Macbook since. I cannot think why it will not boot.
I am loathed to do a reinstall as I have some things on the Macbook that I had not yet backed up.
Any advice?

KT6 Delta won't boot after clearing the BIOS

I have just put together the machine as per my signature and run into a few problems. The XP 2800 mobile is not recognised as such but as a XP1800 when I set the FSB to 133. Am I right in saying this CPU should run at 1.65 volts as it seems to wants to run at 1.75. I changed the V Core to 1.65 and it boots ok but when I tried it at 1.6 it did not want to boot, ie no video output. I no longer get the single BIOS bleep and the monitor stays on standby. This has happened before and I got it running again by clearing the CMOS and reseating the RAM but this time I have done the same and it won't boot. Is there anything else I should be doing please. Many thanks.
Having looked at the Socket A sticky I see that my diagnostic D bracket is showing 1,2 and 3 showing red and four not on at all which would seem to point at the graphics as being the problem.

Hello!
Voltages should be set to "CPU default" or similar. Your processor comes in different versions, try setting to 166 instead of 133. Always when changing processor one should clear CMOS, by powering off, unplugging power cable, and then move JBAT jumper for a short time, a minute or so.

My Mac Pro won't boot after installing the latest update

Im running the latest OSX on my mac and recenty did a small updated that i believe contain a few security thing and bug fixs but when restarting the machine after the update it would not boot again after the apple logo has appeard apple script is displayed on the screen contain what i think is boot script failing to run. I have been able to boot the system in safe mode. does anyone have and solution for this as i realy don't want to reinstall the OS
Thanks

The most common cause for "Won't boot after software Update" is Directory Damage that existed before the Update, but was made worse by adding files during the Update.
The most common cure for that Directory Damage problem is to boot in Safe Mode, which takes five minutes to repair the disk, then comes up demanding your username and password, even if you normally auto-login.
Rarely, third-party add-ons are made obsolete by an update. In this case, booting in Safe Mode (with few Apple extensions and NO third-party extensions loaded) works fine, even if normal mode does not work.
Have you tried normal mode again after your Safe Boot?

My G5 won't boot up. The Gray screen comes on and it thinks about it until the fan revs up like it is about to explode. A friend said to start it up with the OS disk and then go to utilities. Didin't work. Any suggestions? Isn't there a key stroke to help

Oh, so this is where I ask my question. Sorry, first time here. As I was saying in my long intro, the gray screen come up and the thing is spinning at the bottom, but nothing happens. Then the fan starts reving up like it is about to explode and I have to manually shut it off. A friend told me to start it up with the OS disk and then go to utilities. I couldn't find the thing, so I went out and bought another. Needless to say, it didn't work. Is there a key stroke to help jump start the machine? How can I get into this thing? I would prefer not to take it in because there are a lot of things on there I don't want just anyone to have access to.Thanks, in advance, for your help!

The last time you had to hold down cmd opt pr more than twice was a decade ago....
G5? PowerPC? 10.5? or earlier....
https://discussions.apple.com/community/desktop_computers/power_mac?view=discuss ions
Apple has a number of resources like "Power or Startup Quick Assist"
http://support.apple.com/kb/HT1149
Your drive does need to be repaired, and best things to buy are another backup recovery drive, with a small OS X partition; a copy of Disk Warrior is expensive @ $90 but excellent and best.
Never bother with or use the drive or reinstall while there are errors. Don't take a "clean' bill from Apple Disk Utility to mean there are no errors. Only that it didn't find what it looked for.
http://www.macintouch.com/readerreports/harddrives/topic4557.html#d12aug2010
http://www.alsoft.com/DiskWarrior/index.html
A quick search "keyboard shortcuts" takes you here:
http://support.apple.com/kb/HT1343
how to resolve and fix startup issues with fsck and disk utility:
http://support.apple.com/kb/TS1417
http://macperformanceguide.com/Mac-HowToClone-backup.html
http://macperformanceguide.com/Mac-HowToClone.html
How to use DU to backup and restore
http://support.apple.com/kb/HT1553
http://www.alsoft.com/DiskWarrior/index.html
http://www.bombich.com/ccc_features.html
Make sure to have multiple backup sets and of your system so if there is a serious problem, you can just erase and restore to be back runninig.
Sounds like your G5 though needs PMU reset, not PRAM, and the best way for those is to clear nvram instead. might even want to check for dust; tell what System Profile says (later) as to "PowerMacX,Y" or "MacProX,1"
http://www.apple.com/support/powermac or /macpro
http://www.apple.com/support/sitemap/
The Utility menu is on the menu bar of an "OS X Install DVD" and at the point where you get to but stop at "install....' for OS X. you probably do need to install OS X on another drive to work from.
Oh, a real severe issue and damage to the drive directory or filesystem CAN in cases prevent booting from DVD (the system still tries to find and see what boot volumes are present) and can help to pull or disconnect the drive. Putting a drive in a FW case to turn on after startup is very useful.

IMac G3 Won't boot up to the OS

I have an older iMac G3 (400mHz/256 RAM/20gb HD) running Panther that all of a sudden will not boot up to the OS. I tried zapping the PRAM, to no avail. All I get is a grey screen, with a purple folder and a question mark in it. I tried letting it be to see if it would come up, but that didn't work either. I am guessing a system's folder is corrupt? It's weird because it worked fine yesterday and I started it up today to give it a spin before I gave it to a friend to save her from the Window's world. Any thoughts or advice? Thanks in advanced.

Hi Rachyl,
couple of ?s for you.
Do you have an install CD/DVD?
Is OS 9. installed on the machine.
Panther doesn't use a system folder, as such. Even if corrupted, it should still boot to some degree. The Folder with ? simply means the machine can't find a startup disk. Your hard drive may have failed. If you have an install/recovery CD/DVD, boot while holding down the "option" key. This will bring you to the option boot screen. Load the CD/DVD and click on the refresh icon. When the CD/DVD shows up, select it and hit the arrow icon to continue booting. Once the machine is running on the CD/DVD, try to repair the hard drive using Disk Utility.
If OS 9 is installed, it should show up as a boot-able drive in the option boot screen. If so, you can select it and try to boot into OS 9.
Let us know how you make out,
Rick

MacBook Won't Boot Up All The Way

Hi, I have had my macbook for quite a while, and it has had problems before like a non working battery and random brightness changes but ever since I installed the latest security update it will not boot up all the way, first it takes a long time for it to pass the white screen with the Apple logo and loading circle, after that it reaches a blue screen, with no response. Once it made it to my desktop background but none of the icons or dock showed up. Any help?

I have the same problem mentioned in the original message. I downloaded the updates and my computer will no longer boot up. I put in Disk one of the install disc, but that did nothing and now I can't get the disk to eject. I was going to try disk 2, but can't get disk 1 out.

Intel imac won't boot with usb powered hub attached

My intel imac has started to not boot with a powered (have tried a variety of them) attached. Just stops at the white screen. Also, after I attach the hubs (2, both powered) the computer got into spurts when it just kicks everything attached to the hubs off saying that something pulled too much power. At other times it is fine with the same set up. I've tried resetting the PRam but it didn't make any difference.
I see from other postings that this isn't too uncommon, but didn't see any fix.
Thanks

Can you determine if it is just one of the hubs? Resetting the PRAM probably didn't have anything to do with this problem but the SMC controls the power, try this reset:
SMC RESET
http://support.apple.com/kb/HT3964
Shut down the computer.
Unplug the computer's power cord and ALL peripherals.
Wait 15 seconds.
Attach the computers power cable.
Wait another 5 seconds and press the power button to turn on the computer.
The 5 second timing is important to a successful reset.

My PC won't boot up if the hub is already switched...

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