Hi, guys.
I am replacing the capacitors on an Apple iigs power supply. The model number is 699-0126.
I found something peculiar.
I am fiddling around with two of these power supplies.
All of the radial electrolytic capacitors on these have the same value except 1!
One has a capacitor with a value of 300μF 200V.
And on the other power supply has in the same location a capacitor with a value of 330μF 200V!
I could only find one place online that has a capacitor that has the value that can be used as a replacement (300μF 220V). This capacitor is very hard to find.
But I can easily get a capacitor with a value of 330μF 200v. I even think I can find one locally.
I would rather not have to deal with some place online that I have never heard of before.
Would it be okay if I were to replace the 300μF 200V capacitor with a 330μF 200V capacitor?
This capacitor is the largest one inside the power supply. I think it's capacitor C4 bit I am not sure.
What do you guys think?
Hello insanitor,
You don't mention the brand of the PSU : Dynacomp or Astec ?
Based on the schema and several pictures, I think it's an Astec one. You are probably talking about C4.
The problem is the value is 100µF/400V everywhere where I look.
A picture would help.
Hello,
both may just view still different supplies ?
one viewing US version ( with 100µF ) at netfrequency of 60 Hz
and the other
viewing the european version ( with 300µF ) at netfrequency of 50 Hz.....
short explentation:
C4 is used to "equalize" the voltage after it has been rectified.
Higher frequency at net means more duty cycles with shorter time of charge and discharge - demands smaller capacity
lower frequency mean less duty cycles and extended time of charging and discharge - that demand larger capacity
back to the question
the 300µF is the minimum value and 330µF is a permitted replacement.
speedyG
You are right. It's Astec Model AA13581.
The pictures you provided match perfectly.
I called the store where I got all the other capacitors and I can buy the 330 Microfarad capacitors locally.
I will do this today so I will report back here. I will check the voltages with a DMM under load (from a running iigs).