lenny@icus.UUCP (Lenny Tropiano) (08/21/88)
In article <228@tarkus.UUCP> jcs@tarkus.UUCP (John C. Sucilla) writes: |>In article <5649@ihlpf.ATT.COM> gmark@ihlpf.ATT.COM (Stewart) writes: |>>In article <227@tarkus.UUCP>, jcs@tarkus.UUCP (John C. Sucilla) writes: |>>> (another good reason to install a 110V. constant speed fan). |>> |>>I apologize for bringing this back to the net, but I've lost the |>>old postings regarding fan mods. I stuck with the DC fan, based |>>upon the db listings on the packages. An AC fan is noisier, right? |> |>Nah. |> Well, the 120VAC fan (at least the Radio Shack incantation of it) is noticibly noisier than 12VDC fan that is supplied with the UNIX PC (even when that's running at high speed). It's not *unreasonable* by all means, in fact I've learned to live with it for quite some time now (in my bedroom) :-). |>>What is the reason to use the AC fan? Operation in spite of |>>power supply failures? |> |>Thats a good reason. Another good reason is that the 12v fan is |>junk. Mine failed after 3 months and it seems a lot of others |>have had them fail sometime in the first year. |> Yes, agreed on this one. The 12VDC fans that are in the UNIX PC's are not worth too much (about $4.00 from a discount shop, $12.95 at Radio Shack prices, $100 at AT&T's prices)... I've gone through all different phases with fans. I've tried almost every combination, and the best so far is the current one. 1-120VAC fan running on the right side. I've tried the Radio Shack 12VDC fan on the right (with and without bypassing the thermal thinga-magig on the power supply). While this worked *ok*, I was still worried about the 12VDC fan's reliability. I've tried two 12VDC fans, this worked (or seemed to work) well. This pulled much too much dust through my machine, and probably pulled needed air away from the right side. (Like a few of you out in net-land suspected, this wasn't as good of an idea as I first suspected). Another problem I noticed with the Radio Shack version of the 12VDC fan is that it only pulled 27CFM (cubic-feet-per-minute), and I think the AT&T version pulled 31CFM. The best configuration so far is the 120VAC fan. It's easy to hook up, looks reliable, and pulls about 34CFM. Installation instructions: Shut the machine down (of course), and remove the keyboard. Flip the entire machine from the front backwards, so that the metal bottom is facing you (the part with the serial #). Open the machine (the easy way)... remove the 6 screws that connect the monitor top to the bottom plastic base (Note: This is not the normal way to open the machine if you need motherboard access, this will only give you access to the floppy, power supply, and the fan) Four screws are located on the left and right sides of the monitor facing out at you. Then the two others are near the internal EIA port and the power connect in recessed holes on the bottom. After the screws are removed, flip the machine back in the normal upright position. Carefully pull the top off by holding the monitor, pulling up and towards you. There are two plastic tabs in the front that you need to be careful not to break off. You might hear a *snap* noise, this is nothing to be alarmed about, it is just the tabs being unfastened. Once you have the top off, you can tilt the monitor on the side. Remove the old fan by the red-connector between the fan and the P/S. Slide the old fan out of the slot (save for temporary replacement use). Use electrical tape to cover the old connector to prevent anything shorting against the 12 volt supply. (*ouch*) Place the 120VAC fan in the hole where you removed the old fan. Connect both wires directly to the AC input (where those blue and brown wires are). Solder them in place, polarity not making any difference here [Thanks Gil, :-)] Boot the diagnostic floppy while the machine is open to make sure the fan spins when the power is turned on. Another caution is to make sure nothing rubs against the new fan (ie. the black power cable to the hard drive). If everything checks out (the fan is blowing in the correct direction), put the monitor top back on and tighten all the screws. (*Note: This does void your AT&T warranty and service, so do beware*) (*Double-Note: I don't take and responsibility in this venture or any other hardware tinkering I might suggest*) Good luck with all this... -Lenny -- Paper-net: Lenny Tropiano | @-net: lenny@icus.UUCP ICUS Software Systems | !-net: ...sbcs \ PO Box 1 | boulder \ Islip Terrace, NY 11752 | talcott !icus!lenny Vocal-net: (516) 582-5525 [work] | pacbell / (516) 968-8576 [home] | hombre / Telex-net: 154232428 ICUS | Another-net: attmail!icus!lenny