PB G3 Wallstreet - holy fan noise, Batman!

[trigf]

Just received the latest addition to my collection, a 14 inch Wallstreet model. It appears to be in fantastic condition, except for one little detail: The fan never stops. 

It's on full blast all the time, and I can't figure out why. From the moment the laptop is turned on, a 14 inch wind tunnel is created!

Doesn't seem to be much in these forums or on the internet regarding this, so I'm wondering what your guys' take is?

 

[Unknown_K]

That is not normal. A wallstreet with a dead PRAM battery will fire up the fan full on at boot but quiet down after the bong.

 

[TheWhiteFalcon]

Try a PRAM/SMU reset.

 

[Elfen]

Lets hope resetting the PRAM works. If not the temp sensor is shorted out or removed and the jumper shorted out. Check the heat sink on the CPU, make sure that it is on hand tight and no tighter. No heat transfer goo is needed, though you should check it out by removing and wiping it down with acetone. It should be just bare metal, but sometimes dust can gather around the CPU and need to be cleaned up.

 

[MacJunky]

A few years ago I pulled my PDQ out and the fan had started running constantly. I unplugged it. Perhaps because I live in Canada or not, I have never heard the fan come on under any load and I had actually tried using it on soft surfaces at some point in the past. The fan in my Lombard also ran constantly. IDK what was up though it had other issues to begin with.

Do I remember there actually being thermal compound in the WS/PDQ, Lombard, and TL iMac? Between the CPU die and heatspreader I mean..(the black disk on the CPU)

Or was that a little metal shim with an equally thin thermal pad on one side? I forget. these G3s are pretty tame anyway.

 

[Elfen]

Do I remember there actually being thermal compound in the WS/PDQ, Lombard, and TL iMac? Between the CPU die and heatspreader I mean..(the black disk on the CPU)

Or was that a little metal shim with an equally thin thermal pad on one side? I forget. these G3s are pretty tame anyway.

I have three Wallstreets. There is no heat compound goo or metal shim between the cpu and the heat sink on any of them, but the heat sink where it met the cpu die was shiny, and on one of them, a lot of dust gathered about the CPU under the heat sink.

 

[MacJunky]

Just so we are on the same page, you are talking about removing the black disc, right? Black disk being the heat spreader held against the CPU die by a square plastic piece around the whole CPU package. Then the big metal plate under the keyboard is the heatsink.

On the underside of the black disc I forget what Apple used most commonly, and I would check mine but I am quite certain I squirted some thermal compound under the heatspreaders of my daughtercards after cleaning them out however many years ago. Normally I would want to refer to the disk as an IHS(integrated heat spreader, like what I removed from my i7 4770k! ) but it is not exactly integrated, just more slapped on IMO.

Oh, and my mentioning the TL iMac was incorrect, I forgot about it's rectangular heatsink that butts up directly against the die and is held down by a clip to whatever that daughtercard cage thingy is.

 

[Elfen]

Just so we are on the same page, you are talking about removing the black disc, right? Black disk being the heat spreader held against the CPU die by a square plastic piece around the whole CPU package. Then the big metal plate under the keyboard is the heatsink.

On the underside of the black disc I forget what Apple used most commonly, and I would check mine but I am quite certain I squirted some thermal compound under the heatspreaders of my daughtercards after cleaning them out however many years ago. Normally I would want to refer to the disk as an IHS(integrated heat spreader, like what I removed from my i7 4770k! ) but it is not exactly integrated, just more slapped on IMO.

Oh, and my mentioning the TL iMac was incorrect, I forgot about it's rectangular heatsink that butts up directly against the die and is held down by a clip to whatever that daughtercard cage thingy is.

Yes, its that "disc". I always considered the disc on top of the CPU as the heat sink and on my 3 Wallstreets there is no heat/thermal compound goo or anything else on it or the CPU. Where that disc is pressed against the CPU it is polished to promote the heat transfer to its maximum level. (That is why I consider it as the heat sink.)

The metal plate that is part of the em-shield under the keyboard that you refer to as the heat sink, I see that there is some kind of thermal/insulating tape there. I see now that it it part of the heat dissipating mechanism; similar to old CB Radios where the final amplifying transistors are on a heat sink and then the heat sinks up against the radio chassis. In those cases, the radio chassis is not considered as the heat sink but as electronic ground. It draws away the heat from the finals was a secondary function being exploited. This design is also in the LC and IIcx/ci Power Supplies, where there are power transistors/regulators in the middle of the board tied to a heat sink and then that heat sink tied the PSU's case. The PSU casing is not the heat sink but it being taken advantaged of as such for this process.

In both cases there is some kind of heat/thermal compound goo on the heat sink and the chassis/psu casing. So I also believe this piece on the Wallstreet is doing the same thing - doing one job of EM shielding while at the same time being taken advantage of for drawing away heat. In the past in testing, I have ran the Wallstreet (a 233MHz) for three hours as a test without the shielding but with just the heat sink disc without ill effect on the system.

 

[MacJunky]

http://en.wikipedia.org/wiki/Heat_spreader

"A heat spreader is a heat exchanger that moves heat between a heat source, and a secondary heat exchanger whose surface area and geometry are more favorable than the source."

http://www.thermacore.com/products/heat-spreaders.aspx

"Heat spreaders let you move heat from within enclosures, where space may be at a premium, to areas with a larger cross-sectional area, surface area and/or volume and a lower heat flux."

If you want to get nitpicky, "heat spreaders" you find on RAM are not fitting of that designation unless they are used in this fashion:

http://www.creationbs.com/store/index.php/watercooling/cpu-blocks/ek-ram-monarch-x4-nickel-csq.html

Anyway, I know both of my WS/PDQ CPUs (and Lombard CPU) had something between the black disk and CPU. I just forget what it was originally. The PDQ is under a pile of stuff atm and I do not remember where I put the old daughtercard.

If you look closely at the WS/PDQ & Lombard heatsinks they actually have a heatpipe extending away from the centre where they contact the CPU's spreader.

Heatpipes go between centre and left in these pics.