Electronics > Repair
Macintosh SE PSU IC identification
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fzabkar:
There is an 8-pin uPC358C dual op-amp in that other circuit which is functioning as a voltage detector for the +5V and -12V rails. I suspect the "177" IC is also some kind of voltage or current sensing circuit.
gkmaia:
I am still stuck with this one.

I've tried a precision opamp op177 and no success. Also tried the conventional single and dual op amps no success...

Would the  IR2175 current sensing IC be an option?

I am gambling... I have absolutely no idea what this little daughter board does.

CJay:

--- Quote from: CJay on November 30, 2020, 02:10:45 pm ---Given Unitrode tended to be *big* in SMPS controller ICs and that's from a PSU, I reckon there's a good chance it's something like one of the UC384x family, a wider pic of the rest of the unit and maybe the back of that board might be useful...

--- End quote ---

gkmaia:

--- Quote from: CJay on January 01, 2021, 09:38:36 am ---
--- Quote from: CJay on November 30, 2020, 02:10:45 pm ---Given Unitrode tended to be *big* in SMPS controller ICs and that's from a PSU, I reckon there's a good chance it's something like one of the UC384x family, a wider pic of the rest of the unit and maybe the back of that board might be useful...

--- End quote ---

--- End quote ---

Spot on!!! Thanks, the PSU works now!
CJay:

--- Quote from: gkmaia on January 10, 2021, 08:38:12 pm ---
--- Quote from: CJay on January 01, 2021, 09:38:36 am ---
--- Quote from: CJay on November 30, 2020, 02:10:45 pm ---Given Unitrode tended to be *big* in SMPS controller ICs and that's from a PSU, I reckon there's a good chance it's something like one of the UC384x family, a wider pic of the rest of the unit and maybe the back of that board might be useful...

--- End quote ---

--- End quote ---

Spot on!!! Thanks, the PSU works now!

--- End quote ---

SO, which chip was it? Only that might be useful for other people in future?
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