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Dimesion 8400 won't boot
My Dimesion 8400's fan is so loud that it is about as noisy as a *** cleaner. It blows papers off my desk. The computer doesn't boot up, though. I have opened the case and cleaned everything, vacuumed out all the dust, taken out and reinstalled all the parts I can, replaced the battery, and still no luck. Any help would be greatly appreciated.
shesagordie
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October 20th, 2015 14:00
Damascus2
Is the power switch LED, solid green, blinking green, solid amber, blinking amber?
Check the sequence of the diagnostic lights on the back panel of the case, see Here:
ftp.dell.com/.../dimension-8400_Owner%27s%20Manual_en-us.pdf
Are there any 'Beeps', or error messages?
While the case is open, you check the motherboard for any capacitors with bulging tops or are leaking, the tops should be perfectly flat.
Bev.
speedstep
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October 21st, 2015 08:00
Airplane mode indicates bad capacitors on the motherboard and or inside the power supply.
Damascus2
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October 21st, 2015 12:00
No beeps. Capacitors all look good. None of the four diagnostic lights are on. Power switch light is solid and appears to be green, although it might be amber. I am color blind and it's a small light.
shesagordie
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October 21st, 2015 13:00
Note: The only 100% method of testing a PSU, is to install a known working power supply.
Unplug the cord from the power supply, hold the power button in for about 15/20 seconds, open the case, unplug the 24-pin power connector from the motherboard and jump the Green wire to one of the Black wires, reconnect the power cord and power the system on, if power supply, case fans and the hard drive run, then the PSU may be good.
Note: Do not remove any wires from the plug, use a small piece of wire or a paper clip as a jumper.
Power supply checks out and the system still does not work, again remove the power cord, hold the power button in for several seconds to discharge the residue power, reconnect the 24-pin connector to the motherboard.
Remove all the PCI cards, the video card [if applicable], memory, all peripherals, disconnect the data and power cables to all the drives, check that the front panel cable is connected to motherboard, with nothing else connected to the system, reconnect the power cable and power the system on.
If there is no difference in the diagnostic lights, 'Beep' codes and/or the LED indication of the power button, then it would appear that the motherboard has died and/or maybe the processor.
Note: The good news is, processors rarely fail, as the only method I know of checking a processor, is to install it a compatible working PC, or use a known working processor.
Bev.
speedstep
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October 23rd, 2015 12:00
Optiplex GX620 or better Mini Tower units are good crossover replacement systems.
https://www.walmart.com/reviews/product/22985035
Damascus2
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October 23rd, 2015 12:00
I'm not sure what you meant by jump the wire, but I did disconnect everything except the power supply and the diagnostic lights still don't come on and the fan still blasts. I guess it's time for a new computer. Thank you very much for your help and I'm off to the store.
shesagordie
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October 23rd, 2015 13:00
Damascus2
Good luck at the computer store, have fun shopping.
You can read this document about 'jumping the wire' to test a power supply:
http://aphnetworks.com/tutorials/psu_paperclip_trick
Bev.
2-J
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October 24th, 2015 05:00
Perhaps the original poster has already bought a new computer by now, but the issue is probably the one described in the following post:
htt p://binglongx. com/2010/12/12/dell-dimension-8400-boot-problem/ (take out the spaces and copy paste to browser)
Certainly I was affected by this issue with my 8400, and you can see from the comments on that article, many others were also affected.
What happens with some 8400s after a long time is that "Prescott CPU produces so much heat, over the years it comes to the point that a slight push from the distorted green fan shroud, combined with an aged heatsink locking mechnism under heat (that’s why some people argue using a screw-based instead of lock-based heatsink), creates (intermittent) loose connection between CPU and heatsink and/or between CPU and motherboard" and so the PC thinks there is no CPU installed.
I got around this issue for about a year by just physically pressing down on the heatsink / shroud when I turned on my 8400. This made the PC 'realise' there was actually a CPU there. For a more elegant solution, the person who wrote the info in the link above, suggests an arrangement with elastic bands.
Damascus2
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October 24th, 2015 07:00
Thanks for the interesting post. I have indeed bought a new computer and am very satisfied with 10 years of service from the Dimension. It's just time.
jan8
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October 24th, 2015 13:00
Hi
Check that it has been installed facing towards the inside of your computer. If it is blowing things off your desk it may have been inserted facing the wrong way . If it isn't cooling your system properly the system may automatically shut itself down due to overheating
Jan
Damascus2
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October 27th, 2015 10:00
Perhaps you can give me a quick idea. I absolutely must have a full size graphics card ability and the ability to put in a second hard drive. Do the Optiplex towers and many towers offer that?
speedstep
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October 29th, 2015 18:00
None of the Optiplexes have full size video slots. If that is a requirement you should look for precision 380 or better.
Damascus2
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October 29th, 2015 20:00
Bought the Inspiron 3847
shesagordie
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October 29th, 2015 22:00
Damascus2
Congratulations, enjoy the Inspiron 3847.
Remember to make the DVD, or USB recovery media ASAP, as Dell no longer ship the OS reinstallation disc with the computer.
Bev.
Damascus2
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November 17th, 2015 06:00
Thanks for you responses. Unfortunately the 3847 arrived damaged and has been sitting in the repair depot for three weeks while the parts are on back-order. Tech support has been a nightmare, one guy lied to me and said it's fixed and the next said the parts are unavailable. I just want this nightmare to end and to get a refund and leave Dell forever. I can see why they've slipped from #1 to #4 in PC sales. Terrible service, lying reps, and poor products.