when i measure the resistance R7R17 when the power supply is not plugged it give me 9.8k when i plug the power supply it give me about 6k is that normal???
question about R7R17 resistance
- Thread starter nolimit5005
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You could kill your 360 (or any other equipment), and you might kill the multimeter too.
A multimeter measures resistance by using a certain voltage and amperage, when the circuit is powered the voltage/current of the circuit may interfere with your multimeter, thus your measurement may/will be off.
Also, your multimeter has a certain internal resistance, when you measure a resistor you put that resistance in parallel with the resistor you measure, causing the overall resistance to drop, resulting in more current going through the circuit.
I'm pretty sure the internal resistance of a multimeter is quite high (probably several Mega Ohm), so the overall resistance wont drop a lot, but in some cases it may drop the resistance enough to blow a component (If the resistor is used as a current limiter/voltage divider for example). EDIT: Forgot to mention that if the internal resistance of the multimeter is 20M Ohm and you're measuring a 20M Ohm resistor the overall resistance will drop ~10M Ohm, which is a lot.
I never looked in to it, but you just shouldn't measure resistance when something is under power.
A multimeter measures resistance by using a certain voltage and amperage, when the circuit is powered the voltage/current of the circuit may interfere with your multimeter, thus your measurement may/will be off.
Also, your multimeter has a certain internal resistance, when you measure a resistor you put that resistance in parallel with the resistor you measure, causing the overall resistance to drop, resulting in more current going through the circuit.
I'm pretty sure the internal resistance of a multimeter is quite high (probably several Mega Ohm), so the overall resistance wont drop a lot, but in some cases it may drop the resistance enough to blow a component (If the resistor is used as a current limiter/voltage divider for example). EDIT: Forgot to mention that if the internal resistance of the multimeter is 20M Ohm and you're measuring a 20M Ohm resistor the overall resistance will drop ~10M Ohm, which is a lot.
I never looked in to it, but you just shouldn't measure resistance when something is under power.
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thanks for help man and plz another three questions
1)The resistance R7R17 give me 9.8k on the 200k range of the multimeter while it give me 7.3k on the 20k range of the multimeter i don't now why
2)the pll_baypass is about 70mv is that normal?
3)when measure the pll_baypass resistance without R7R17 it give me very high resistance i think more than 100k is that normal too?
1)The resistance R7R17 give me 9.8k on the 200k range of the multimeter while it give me 7.3k on the 20k range of the multimeter i don't now why
2)the pll_baypass is about 70mv is that normal?
3)when measure the pll_baypass resistance without R7R17 it give me very high resistance i think more than 100k is that normal too?
1) You should always use the range that is closest (yet higher) to what you're measuring. But depending on the multimeter it may select a different range automatically.
The tolerance may be higher in the 200K range when you measure below a certain resistance, probably 20K in your case (I'm guessing your MM has a 200, 2K, 20K, 200K and 2M range).
Best way to rule out any other possibilities is to measure a couple resistors that are not in a circuit, that way you'll know if it's your MM.
Lets say you measure a 10K resistor with a 5% tolerance, it should measure between ~9500 and 10.500 Ohm (9450 and 10.600 or so is fine as well, your MM has a tolerance too, depending on the range and the quality of your MM the tolerance varies, not to mention contact of the probes, quality of the probe leads...).
Sorry, can't really help you with the other questions as I still need to RGH my first 360 (Have a JTAG'ed 360 myself, and only work on consoles for friends, neighbors and the like).
PS: Edited my previous post, forgot to mention something.
The tolerance may be higher in the 200K range when you measure below a certain resistance, probably 20K in your case (I'm guessing your MM has a 200, 2K, 20K, 200K and 2M range).
Best way to rule out any other possibilities is to measure a couple resistors that are not in a circuit, that way you'll know if it's your MM.
Lets say you measure a 10K resistor with a 5% tolerance, it should measure between ~9500 and 10.500 Ohm (9450 and 10.600 or so is fine as well, your MM has a tolerance too, depending on the range and the quality of your MM the tolerance varies, not to mention contact of the probes, quality of the probe leads...).
Sorry, can't really help you with the other questions as I still need to RGH my first 360 (Have a JTAG'ed 360 myself, and only work on consoles for friends, neighbors and the like).
PS: Edited my previous post, forgot to mention something.
plz can anyone answer the two other questions
2)the pll_baypass is about 70mv is that normal?
3)when measure the pll_baypass resistance without R7R17 it give me very high resistance i think more than 100k is that normal too?
2)the pll_baypass is about 70mv is that normal?
3)when measure the pll_baypass resistance without R7R17 it give me very high resistance i think more than 100k is that normal too?