Alert! Previous Fan Failure.

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if your fan is rated at 1.2 amps you need a 10 OHM / 15 watt resister across the red/black wire; with the white wire (signal) going to the negative of the header. @ .42 amps you will need a 5 watt 28 OHM resister.
I wouldn't be doing this :suspiciou

Just buy the correct fan.
And by the way, this is one of the causes of many No POST issues on system builds. Where the User has put in the incorrectly rated fan
 
Comments on Custom Fan Modification

say you replace the fan with another type. (ie. not the original) , the fan works, but it will still give the error.. why? resistance. the original fan i had was 1.2 amp 12v blower fan. Yes, i said 1.2 amps SOME of them have 0.42 amps (how the motherboard supported this i do not know, i will see if i can get a model number of that fan) this is a 4600C Dell, which I love BTW except that i cant get any fan speeds or anything under lm_sensors for some reason, looking for help on this myself)

The 1.2 amp 12 volt blower fan that you mentioned is typical in Dell computers that have passive cooling (no fan on the heat sink) complimented by a green shroud to help control air flow. The fan requires higher power consumption to increase the CFM (cubic feet per minute) because its proximity to the heat sink is more distant. This configuration is not common and therefore most replacement fans will not work properly. Moreover, controlling the speed of this type of fan will require a variable pulse width modulator instead of a rheostat, which is ultimately not worth the complication (unless you are repairing a computer on the international space station and do not have a decent part supplier ... then again, I doubt that the ISS has any Dells, and therefore I digress...)

Otherwise it may be a CPU fan for something like an Intel Xeon processor or a case fan for a power hungry server.

if your fan is rated at 1.2 amps you need a 10 OHM / 15 watt resister across the red/black wire; with the white wire (signal) going to the negative of the header. @ .42 amps you will need a 5 watt 28 OHM resister.

Regardless of what is "proper" and the fact that you can "buy the correct part" ... I find your solution to be interesting, experimental, and ultimately impressive. Sometimes there are no spare parts available and it takes a custom modification to get the job done. Your math is not exact, but it is close enough to not fry the board, and therefore ... if it works then it is a solution!
 
I just replaced a CPU fan/heatsink on a 2002 Intel Dell desktop. I used another heatsink assembly taken from a scrap motherboard. The 2 assemblies were similar, but the mounting brackets, attached to the motherboard were different. I was able to remove the burned out fan assembly completely, and the new heatsink assembly fit fine. The "Alert! Previous Fan Failure" stopped
 
Regardless of what is "proper" and the fact that you can "buy the correct part" ... I find your solution to be interesting, experimental, and ultimately impressive. Sometimes there are no spare parts available and it takes a custom modification to get the job done. Your math is not exact, but it is close enough to not fry the board, and therefore ... if it works then it is a solution!

MarkMartin57, thanks for your response, i appreciate it!

what is wrong with the math??? good luck trying to find a 14.4 watt resister lol
the 28 ohm 5 watt; however, you would have to go with 30 ohms. i couldnt find one of those either.

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I would also like to note.. I dont know what FanSpeed or other similar software for windows would say about speeds or anything after this bypass on any other board, this was a fix for the dell 4600C which i have, and ive never had any sensor software give me ANYTHING for the board I have. Since i'm running linux, for some reason even lm_sensors will give me nothing even though it found the chips to read temps and speeds. Before and After the bypass.

that is all.

Good Luck
 
Same Problem

Hi,

I have had the Dell Dimension 4300 for 8 years with hardly any problems.

Recently the above has started to happen.

As I needed a PC urgently I bought a new PC.

I have managed to get the data from the hard drive using a Hard drive enclosure, and transferring data to new PC.

I now want to repair the old machine to use it as a spare secondary machine.

I am happy to experiment as I consider it a write-off (ish).

1) The fan(s) are working as I can see them turning.
2) I have tried clearing all the logs etc - doesnt work.
What happens is as its loading a blue screen of death appears and then it just starts re-loading atnd the same thing happens.

How can I find out if the CPU has fried?

I am happy to replace it, if I could confirm thats the problem.

I could but a 2.8 ghz chip for £80, 1 Gig of RAM for £80 and a hard drive, and all of a sudden I have a half decent machine.

Its only worth it if I know the CPU has the problem.

The other problem I have is that i stupidly deleted all the data from the hard drive I took out after transferring the files I needed.

Your help would be greatly appreciated.

PS: I am not the greatest with PC's.....
 
It might not be economical but if the purpose is to experiment and learn, then it might be worth it to play around with, provided the repair solution is not too expensive. That said, you should have started a new thread as your issue has nothing to do with the original topic.

It would be very helpful if you had another PC similar to the one you have now to test parts on. Your new PC is probably not suitable for most components. Do you happen to have one?
 
This could have benefited by being in a new thread... If the CPU is an Intel socket 478, there are still motherboards available, with updated memory, and on-board video. The motherboard, power supply, hard drive, any memory and CD drives are most likely trash
 
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