Dimension 8400 Processor & Motherboard

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Dimension 8400 Processor & Motherboard

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New to this forum - any help would be appreciated.

 

1.  Is there a different processor I can use in this system?  I currently have the original C3826, 80547, Penium 4 Prescott DT, 3.2GHz and I know these (Prescott) tended to run very hot.  I'm looking for a substitute that would work in the original motherboard and run cooler.  Perhaps even one that did not require that very large cooling fin-heat sink.  Was there a Dell upgrade processor?  Did they ever change the heat sink/fan assembly to one where the fan sits right on top of the chip?

2.  Is the motherboard still available?  I think it is a Foxconn 925XE7AA ---------, but am not sure.

3.  Did the heat sink thermal grease ever require replacing?  Could that be the cause of my excessive fan speed?  I have read the the Dell Service Manual that when replacing the processor, the original heat sink should be "discarded" and returned to Dell.  My only thought here is that perhaps they sent out a replacement heat sink (the same kind) that was clean from any embedded grease/thermal paste and the old one would have had the grease compound in areas where it would have had to be "factory cleaned" before reuse.

I know the 8400 is old, by today's standards, but it fits my needs - its just that heat problem that is causing me concern.  And, my fan had taken on the "jet engine" symptoms that seem to have no one solution - I have seen processor, power supply, mother board, etc. solutions and now I'm getting worried.  I'm also still running WindowsXP Pro and the max ram is not a problem.

 

Thanks very much.

 

 

Verified Answer
  • Roxie2401

    Did you buy your 8400 with the audio card [SoundBlaster Audigy] option?

    Yep, that's how the motherboard is installed, for more info, go HERE

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
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  • Breakdown24

    Bev,

    What is the link for the alternative cooler that you were describing above? I can't seem to find the link anywhere on the page or forum.

    Breakdown24

     

    If you mean the Zalman CNPS7700-CU heatsink, this is an EOL product, but is still available from Amazon,

     http://www.amazon.com/Zalman-CNPS7700-CU-120mm-Ball-Cooling/dp/B0006VHVK0

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

All Replies
  • I'd stay with that CPU as I think it is th max speed anyway.

    Work on improving your cooling. Start by cleaning the bottom of the heatsink and top of CPU. This can be done easily with rubbin alcohol. Next apply new thermal paste. Arctic Silver is the best by far and I use the Ceramique one.

    If that does not improve the cooling do some research on compatible heatsink/fan combos preferably one that runs quiet.

  • Roxie2401

    Yes, you can still buy Dell OEM 8400 motherboards.

    You can upgrade to any Socket LGA775, 5xx, 6x0 or 6x2 processor, with 90nm architecture, but not the 6x1 processors.
    8400 systems do not support dual core [Pentium D] or Core 2 Duo processors.

    The 670 3.8Ghz is the largest.

    I have a 660 3.6GHz processor in my 8400.

    My 8400 had the noise problem, but instead of using a replacement Dell heatsink, I carried out the following: Installed a Zalman 'CNPS7700-Cu' 918gram [2+lbs] copper heatsink, with a 120mm fan, while the installation was not quite as easy, as described HERE, it is still doable and works well.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Hi - thanks for the prompt response.  I'm curious - is it possible for the heatsink to move slightly (by opening the case and blowing the dust out, or adding more memory, etc.)?  If that happens, then, if I understand correctly, remove the existing heatsink, clean both the sink and the top of the processor chip, add the Arctic Silver, and reseat the heatsink???

  • Bev,

     

    Thanks.

     

    First, how do you correctly identify the motherboard?  I have my original Dell shipping inventory, but they didn't list the motherboard.  I was guessing it was a Foxconn - but you seem to think Dell would know my correct MOBO?

    Second, what exact processor did you mean when you said you had the "660 3.6GHz?"  Is it Intel?  Where are they available?  What do I have now?  I know its 3.2, but what does the "660" mean?

     

    By the way, my fan issue was the "Steady Amber light and fan speed like a jet engine and no POST.  It has settled down for now, but I have no idea why this happened.  Scared the heck out of me.

  • Roxie2401

    No, the heatsink can only move, if it's not properly connected to the motherboard.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Roxie2401

    Bev,

    Thanks.

    First, how do you correctly identify the motherboard?  I have my original Dell shipping inventory, but they didn't list the motherboard.  I was guessing it was a Foxconn - but you seem to think Dell would know my correct MOBO?

    Second, what exact processor did you mean when you said you had the "660 3.6GHz?"  Is it Intel?  Where are they available?  What do I have now?  I know its 3.2, but what does the "660" mean?

     By the way, my fan issue was the "Steady Amber light and fan speed like a jet engine and no POST.  It has settled down for now, but I have no idea why this happened.  Scared the heck out of me.

    Roxie2401

    Yes, it's an Intel, that's the only brand of processor the 8400 supports.  I purchased mine on eBay, it was a 'pull' [used].

    You can use a small free utility called CPU.Z, that can be download from HERE.

    It will identify the motherboard as a Dell and give the model number.  The motherboard is a Dell, made by Foxconn for Dell, to their proprietary specifications.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Bev,

    The utiltiy is great!  Thanks.  So, if my processor is a 540 and yours is a 660, what changes will I see?  Is it faster?  Does it get just as hot as the one I have now?  Can I use the same heatsink if I don't do the modification you did?  And, when I look on eBay, what do I ask for?  Intel, Pentium 4, 660?  Is it a Prescott, too?

     

    Unrelated, but did you upgrade your graphics card?  Mine is still the X300 ATI that came with the box.

     

     

     

     

  • Bev,

     

    One final (I hope) question - do you have a good utility suggestion for testing memory?  I keep wondering if some of my excessive processor occupancy may have been due to a bad ram area?  Could be way off base, but was wondering if there is a way to test the memory.

     

    Have a great evening and thanks for all the help.  Glad to know someone else is still using the 8400.

  • Roxie2401

    Bev,

    The utiltiy is great!  Thanks.  So, if my processor is a 540 and yours is a 660, what changes will I see?  Is it faster?  Does it get just as hot as the one I have now?  Can I use the same heatsink if I don't do the modification you did?  And, when I look on eBay, what do I ask for?  Intel, Pentium 4, 660?  Is it a Prescott, too?

     Unrelated, but did you upgrade your graphics card?  Mine is still the X300 ATI that came with the box.

     

     

    Roxie2401

    THIS should give you all the information needed to buy the correct processor, 660 is the Intel processor number.

    Yes, you can use the same heatsink, but some the Dell 8400 heatsinks were defective.

    Yep, the X300 was the basic graphics card Dell installed, mine is a PCIe Radeon X800GTO, but there are better cards on the market now.

    Bev.

     

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Roxie2401

    Bev,

     One final (I hope) question - do you have a good utility suggestion for testing memory?  I keep wondering if some of my excessive processor occupancy may have been due to a bad ram area?  Could be way off base, but was wondering if there is a way to test the memory.

    Have a great evening and thanks for all the help.  Glad to know someone else is still using the 8400.

     

    Roxie2401

    Define memory test?

    If just mean, testing the RAM, then THIS this is a good comprehensive memory diagnostic.

    Bev.

    Ps. The 8400 is one of several systems I have, the latest is Inspiron 530 Mini Tower with a Core 2 Duo processor.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Bev,

     

    Yes, it was the memtest that I was looking for.  Thanks.

     

    Just to follow-up - what did you mean when you said "some of the Dell 8400 heatsinks were defective?"  If I take mine out, blow the dust out, clean the bottom & the top of the cpu, reapply thermal grease (Artic Silver), should I be ok?  What was defective?

     

    In looking at the fan modification you did, would an original Intel heatsink/fan combo work?  I found this one on e-bay.  Its not for the 540 but how would it compare to the existing "tower" heatsink and fan? (Sorry, I don't know how to insert a link.)

    http://cgi.ebay.com/INTEL-PENTIUM-4-641-650-651-660-HEATSINK-SKT-LGA775-NEW_W0QQitemZ350153104378QQcmdZViewItemQQptZLH_DefaultDomain_0?_trksid=p3286.m20.l1116

     

    Thanks

     

  • Roxie2401

    You cannot use a standard ATX heatsink, The 8400 have proprietary heatsinks/fans and motherboard heatsink retention brackets. 

    The only upgrade I've found that works is the one, I posted the link too.

    It would seem that some the early model 8400 six pipe heatsinks had problems, causing the system case fan, to sound like a 747 taking off.

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Bev,

    That makes sense.

    Do you mind telling me what memory you have in your 8400?  The CUPZ program tells me I have PC2-4200 with a clock frequency of 266 - the Dell listing that came with the box says I have 533M.

    When I check various sources for replacement memory, the memory calculator indicates I should get PC2-5300 that runs at 333MHz.  For example, Crucial is showing DDR2-667 for the Dell 8400 and that's what I was heading toward - getting four 1gb strips all identical.  (CT907824).

    Am I ok on the clock speed?  Is 667 ok or do I want the 533?  (Even the Dell site is now showing 667.)  What does the DRAM frequency mean?

    By the way, after taking the box over to Geek Squad and plugging it in, finding it booted just fine and returning it home, the 747 jet sound no longer occurs.  Now I wonder if bouncing around reseated the heatsink more firmly.  Its a quiet now as it was when it was new, in 2004.

     

  • Roxie2401

    667 should be fine. 

    Bev.

     

    If my answer was helpful, please use the 'Did this answer the question' and click: Yes
    Forum Member since 2001
    I am not employed by Dell

  • Bev,

    Thanks for all the help.

     

    I feel like I've come full circle.  At times, when I turn the 8400 on, I get the steady amber light and the CPU fan takes off like the 747.  The only way to stop it, is to hold the power button  in until it shuts down.  If I totally unplug the box from the AC and let it sit, sometimes it will boot normally - not always.

    I'm trying to rule out hardware and hope its a software issue, but what would software or boot data have to due with the immediate steady amber power light?

    Should I start a new thread on this forum to see if there is a common cause for this?  I've seen "power supply" (but all my drives, CD/DVD, etc. seem to be running fine); CPU (mine seems ok); MOBO/Memory (again, seems ok).  No one common problem/solution.

    In looking at other threads (and apparently you have seen this before) - I don't want to jump to conclusions, but I do see a couple of capacitors that do not have completely flat tops - nothing dramatic and no side bulge, but just slight curve tops.  Could removing power, letting things discharge and giving it some time allow the caps to work normally for a while?  Once I get it running, it boots normally and runs like a new machine for hours-all day.  But if I shut it down and then restart it, I get the steady amber light, jet fan and have to plead with it to power up normally.

    Oh, I did finally remove the Antivirus and the 100% CPU dropped to 10%.  Any recommendations on antivirus software?  I'm beginning to really hate the one I have now.

    Is all this pointing to a new MOBO?  If so, do you have a suggestion for a compatible (BIOS, chipset, etc.)replacement?  And, IF its the MOBO, will I have to reload the OS or should the HDD data and WindowsXP come up normally?

     

    UPDATE:  I just moved the tower to look at the back panel and it rebooted.  There must be something going on that I don't understand.  Something loose inside?   Also, was searching your recommendation at ascendtech for a replacement MOBO (if it comes to that) and I don't see that they have them anymore.

    And, I just rocked the case from side to side (gently) and it rebooted.  I did unplug everything from the MOBO except the power and started it up and got lots of diagnostic beeps - memory failure, if I counted right - no memory sticks installed.  Then, put it all back together and it booted then hung.

    Any point in reloaded Windows?  The new memory sticks should be here in a day or two.  Maybe I should just stop messing until I can confirm the new memory hangs, too.  I did try the Windows "repair" from the install CD and it hung right in the middle of copying new files.  If not MOBO, then processor or memory???  But why the Amber light at power-up?   Grrrr, I'm so frustrated.  Maybe its time for a new machine.

     

     

    Thanks