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Noisy C128D
Hi - Just got my hands on a very nice C128D ! But, as the previous owner said: The worst thing about it, is the b!¤%& fan. I could just replace the fan with at better one (Papst?) and/or do the 12V-> 5V or resistor hack. But having a small controller, that controls the fan via PWM, based on a temperature sensor, I want to try that. ( What in the PC days was called a 'noice killer' ? ) Now for the question: where should I measure the temperature? My first grues would be the power transistor inside the power supply ( BU508A on my board. ) - Or is there a more 'impotent' component, that will get critical hot? Thanks,
Re: Noisy C128D

holger wrote:

> But having a small controller, that controls the fan via PWM, based on a temperature sensor, I want to try that.

Interesting. I would have never thought of doing that.

> ...where should I measure the temperature? My first guess would be the power transistor inside the power supply...

Hmm, the SID chip runs hot. I've always wondered what its running temperature is. What is the running temperature of the power transistor?

Truly,
Robert Bernardo
Fresno Commodore User Group
http://www.dickestel.com/fcug.htm

Re: Noisy C128D
Thanks - Robert I will keep an eye on the SID chip ( I was only checking the CPU's and VIC's + RAM :- ). But I don't expect any trouble, as long at i make sure the metal shield is installed, and actually touches the top of the chips ( with thermal paste ). The power transistor, In free air, without cooling: after ~1 hour it is 68-69C. Sounds 'bad' but the data-sheet says max 150C (@junktion). So not super worring. I have set my 'noice killer' to start the fan at 40C, and do full speed at 55C. That seams to work - the fan sounds like its running at 1/3 speed, so there is at least some air flow though the rest of the machine. /holger
/holger
Re: Noisy C128D

holger wrote:

> I have set my 'noice killer' to start the fan at 40C, and do full speed at 55C.

Yes, 40 degrees C. is a good starting point for the fan.

FCUG celebrating 33 years,
Robert Bernardo
Fresno Commodore User Group
http://www.dickestel.com/fcug.htm

Re: Noisy C128D
Just a quick followup: The setup seams to work fine. The fan comes on after ~5 min, and tops off at around 1/3 speed. Now the sound is only slightly annoying, and is much lower than the internal floppy drive... /holger
/holger
Re: Noisy C128D

Excellent news! (Especially with the noise level being lower than the floppy drive)

FCUG celebrating 33 years,
Robert Bernardo
Fresno Commodore User Group
http://www.dickestel.com/fcug.htm

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