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November 17th, 2025 01:50
Optiplex 9020 SFF fan full speed
Have the above D/T PC, that was flashing 1-2, which I believe was caused by a faulty USB cable/plug, but that issue now seems to be resolved... (Removed/replaced battery, etc., as well as shorting the M/B jumper...)
Problem now, is the CPU fan is running at full speed/VERY noisy.. Diagnostics gives me a 511 error, which is a 'non-responding' CPU fan - but I can guarantee the fan is working!!
Have tried fixes for this (Reset CMOS/replug - electrical lube, etc.) We ARE close to the ocean, so do get a bit of corrosion/salt on things.
If I need to replace the fan, where can I find a "reasonably" affordable version, as it is an older device, and would prefer not to have to spend a bucket...
Thanks.
redxps630
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15.2K Posts
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November 17th, 2025 17:18
in my experience a full throttle cpu fan means cmos has not cleared the pc. if you have already replaced cmos battery a new one and cleared cmos by jumper, try the jumper one more time and be patient with it. I have seen 9020 after initial loud cpu fan finally coming to grip with cmos and shows DELL logo video = successful post. if cpu fan loud forever after repeated cmos clear, then motherboard may need to be replaced.
hornetster
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November 18th, 2025 05:47
@redxps630
Yep, have tried numerous times to clear CMOS - in the BIOS/using the reset pins on the m/b/removing the battery, several times each.... No change.
Not possibly the fan itself? Fan obviously works fine (I can certainly hear it working! ), would appear if anything would be a sensor issue?? But nothing seems to mention that, all seem to say replace m/b is it's running full speed...
Unfortunately, if I have to buy a fan ($50??), if it doesn't work I've wasted my money, when I could buy a refurb for about $250...?
Thanks.
redxps630
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15.2K Posts
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November 18th, 2025 13:20
9020sff mobo replacement should be quite cheap at least on eBay.us
issue is likely not fan. It is motherboard PWM dialed to max pointing to corrupted cmos.
hornetster
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November 22nd, 2025 11:59
@redxps630
I believe cost is about 1/2 of the price of a new refurbished, so probably not worth it...
redxps630
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November 22nd, 2025 19:03
agree sometimes buying individual old part replacement adds up more than one unit
hornetster
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November 25th, 2025 03:45
@gracemiller84
Thanks for the suggestion, but am in Oz, and the best I can find a fan for is about $50, but can get a fully refurb'd 9020 for $200-250, so still not really worth it....
Will try cleaning connectors, etc, again, just in case, though...