• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

IIsi PSU recap help!

ktkm

Well-known member
I just finished re-capping an IIsi Sony PSU, and it passed the smoke test. However, the PSU won’t start -- it only clicks. This is my first PSU re-cap that I have performed myself, and I’m a bit lost as to where I should look first. Any help is truly appreciated.

View attachment IMG_5080.MOV
 

ktkm

Well-known member
Problem solved. The problem turned out to be a faulty daughter card. I switched to another daughter card from a broken PSU. I changed the polarity orientation of one capacitor (100 µF 6.3 V) following Maccaps reference. Still, I’m not sure if it made any difference or if the old daughter card had other issues? I’d love to get some insight on this matter. Until then, here are some more references.

View attachment IMG_5084.MOV

IMG_5085.jpg
 

joshc

Well-known member
@ktkm The other daughter card probably didn't work because its still full of cap goo - you would need to use hot air to remove components, properly clean everything with flux/desoldering wick/isopropyl alcohol and then resolder the components back onto the board. The big IC particularly needs to be very clean - any crud on the legs could cause shorts.
 

ktkm

Well-known member
The other daughter card probably didn't work because its still full of cap goo - you would need to use hot air to remove components, properly clean everything with flux/desoldering wick/isopropyl alcohol and then resolder the components back onto the board. The big IC particularly needs to be very clean - any crud on the legs could cause shorts.
Thank you, @joshc -- that will be the project for tomorrow.
 

bibilit

Well-known member
I had a IIsi only clicking also. new caps around, daughter board swapped.
After troubleshooting the psu for a while, found two resistors in very bad shape hidden under a transformer , one of them broken (probably the cap goo)

i replaced both, and another one nearby which was corroded... The IIsi fired up without any issue.
 

Attachments

  • IIsi.jpg
    IIsi.jpg
    214.9 KB · Views: 10
Top