RIP My Sweet Dreamcast

[noiseredux]

wait I'm confused... I thought you said he shouldn't adjust the pot, but now you're recommending he adjust it from an 11 to a 3?

I recommended the ego-inducing pot be adjusted from an 11 to a 3, yes. The ego pot isn't a trim pot, so it's salright.

oh sorry. I didn't read your whole post.

[17DaysOlderThanNES]

wait I'm confused... I thought you said he shouldn't adjust the pot, but now you're recommending he adjust it from an 11 to a 3?

I recommended the ego-inducing pot be adjusted from an 11 to a 3, yes. The ego pot isn't a trim pot, so it's salright.

oh sorry. I didn't read your whole post.

except I'm known for not reading the whole thread, not not reading the whole post.

[noiseredux]

thank you, thank you. I feel like we had that well rehearsed.

[CRTGAMER]

It's not a screw...at all. Potentiometers are a variable resistor. Most vary from max to min resistance every revolution.

Finally found a website that backs up my previous statement about leaving the pots the f alone: http://sound.westhost.com/pots.htm

Trimpots
Then of course, there are trimpots (aka trimmers) - pots designed for "set and forget" applications. They are used for "trimming" the value of a resistor, and are commonly used for calibrating instruments, setting the bias current on power amplifiers, and a host of other areas where a circuit cannot be relied upon to give an exact gain, output voltage, or current. Naturally, a normal panel pot can be used, but these are very much bigger, and any calibration or setup control should not be made available for everyone to fiddle with as they please.

"set and forget" is the key word to take from this. Adjusting the potentiometer is like ripping out a resistor and replacing it with another one of a different value. I would argue that just about every case of a pot adjustment being successful was just blind luck and pure coincidence since they probably cleaned and "unjammed" the whole assembly just to take it apart enough to get to the potentiometer to mess with it.

Agree, Idea situation is to leave pots alone. But since the potentiometer is mechanical in the sense of pot contact on that rheostat, over time its resistance values can change. After all previous cleaning, door switch verify, and pin contact checks are tried, what do you have to lose?

17DaysOlderThanNES is correct, you can't "unscrew" a potentiometer. Some even have stops at each end that can be damaged if you keep turning in a given direction. But as components get out of alignment, rather then tossing, a desperation measure is kicking up that laser a little. There is risk of shortening life of an already dead unit, so can't hurt.

[Hobie-wan]

If you have another working DC and a multimeter, try checking the resistance value of the pot on the working one, then try ot adjust the other one to about the same value. Maybe that will get you close enough into tweaking range a you'll have a chance to get it going again if it hasn't already burned something else out.