Display flashing with fan plugged in

harley7892 · Post by **harley7892** » Sat Aug 13, 2005 6:52 pm

Hi. I have an Mx414 and when I plugged a 3.84w Delta 60mm fan into gpo 7 (hi power), the display started flashing on and off, and the fan rpm was erratic.

I had the same fans plugged into 5 and 6, no problem. Yes I do have the unmodified floppy power cable plugged in.

From other posts it seems that each header should handle 1000mw or 1 amp, so this fan is certainly not too powerful. And of course identical fans work on the other headers. When I plug a different fan into this same header it works fine.

Can someone tell me what the flashing display means?

Tom · Post by **Tom** » Tue Aug 16, 2005 10:09 am

Hi harley7892,

I apologize for not getting back to you sooner.

Are you sure the fan was plugged into gpo7. GPOs 1 to 4 is used for high power devices, such as fans. GPO 5,6, and 7 are used for low power devices, such as LEDs.

Each header can handle 12V and maximum of 1000mA, so that makes the header a maximum of 12W maximum output. The gpo will be able to handle the fan.

Can you change the default display to having the gpo turn on, lets say 100%, and just leave the unit running? I want to check whether it is hardware or a software issue.

harley7892 · Post by **harley7892** » Tue Aug 16, 2005 10:14 am

Hi Tom. I meant to say it was plugged into the hi power gpo number 4 (not 7). I have used several of these units, and this one particular several different fans into the fan headers. gpo 3, directly above this one had an identical fan (less than 4 watts). Specifically I wondered if the unit has some firmware in it that causes the display to flash continuously if it doesn't like the configuration, or the particular fan. The unit works fine with other fans.

Tom · Post by **Tom** » Tue Aug 16, 2005 10:24 am

Some fans do generate more noise than others, so it can cause some funny results. The firmware won't be the problem with the display flashing though. I asked about which board revision has been used because rev 1.1 has increase filtering than rev1.0. Do you have the board revision number?

harley7892 · Post by **harley7892** » Wed Aug 17, 2005 1:11 pm

Hi Tom. Yes, all three boards are Rev 1.1. It must have been just that one fan then. Thanks for the info.

Tom · Post by **Tom** » Wed Aug 17, 2005 1:18 pm

Your welcome.

Let me know if you come across anything else.

Best Regards,