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Mac IIsi PSU inductor value

captjon320

Active member
Hello all,

I accidentally removed the L221 inductor from a Mac IIsi PSU when I was removing caps and don’t know what value it was.

If anyone can point me in the correct direction, it would be much appreciated.

I have circled it on the photo for reference.
 

Attachments

  • 15DF3094-EC8F-47A5-8C3A-FE8B349C6E73.jpeg
    15DF3094-EC8F-47A5-8C3A-FE8B349C6E73.jpeg
    736.6 KB · Views: 30

robin-fo

Well-known member
It's 4.7µH according to the BOMARC schematics. If you want to be rally sure, I can open my IIsi's PSU for you to find out more.
 

captjon320

Active member
It's 4.7µH according to the BOMARC schematics. If you want to be rally sure, I can open my IIsi's PSU for you to find out more.
Nice,

Thank you very much. Didn’t realize that I accidentally removed it 4 months ago when I was on a cap removing day!


Would this be an acceptable part?

There is no reason to open yours up, I’m sure the schematic is correct. Where can I find that resource?
 
Last edited:

robin-fo

Well-known member
You can find the schematics for the IIsi and other early 68k Macs here. I cannot confirm that your part will work fine, but it looks right to me. You also need to check for the correct lead spacing.
 

chue

Active member
I happen to have mine open, as I'm recapping it as well. Here's a photo of the marking on the inductor. I don't know what it means, but it says "4R7".
 

Attachments

  • iisi power supply inductor L221 4R7 CROPPED.jpg
    iisi power supply inductor L221 4R7 CROPPED.jpg
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captjon320

Active member
Okay, I can verify that this part from Digikey is a correct replacement part for the inductor above.


RLB0913-4R7K-ND
 
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