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Me too!  Thanks again for your help!

Hmm.. Is it possible the Maxim is a more robust unit?

It makes sense to me.  If the opamp's output is way off, yet everything else checks out, then it must be toast.  I did swap Q207 at the same time, but it tested good once I had it out of circuit. FYI, I replaced the original LT1179CS with a MAXIM unit.  $10 a pair on eBay.  Not sure what the...

Success!  It appears the opamp swap DID work after all! Just for kicks I connected everything up, and performed a power manager reset.  It booted fine, and reported the battery nearly full, and charging.  With the machine booted, Pin 52 now measures 3.94v and climbing. Maybe bad op-amps are a...

Difficult to find time to work on this one.  That's the reason for the long delays in my response. Resistance between PMGR's pin 52 and ground and VCC is about 24meg.

Good timing.  I just now swapped the op-amp and mosfet Q207 out.  I haven't booted it yet, but I still read 1.24v @ the PMU.  So it appears unchanged as you expected.

Swapped the ceramic @ C26 with a lytic.  Same issue.  Next will be an opamp swap. Gotta say this is a real PITA without schematics.

That's what I meant.  Good continuity to pins 14 and 15 of the opamp.

Yes, 1k from the source on Q207 to pin 52 of the PMU. C26 connections are OK, even though the joint isn't flowed very well.  I believe maccaps/uniserver/Charles did the recap on this board. I'm weary of the use of ceramic caps in place of lytics.  I've seen plenty of tants used in place, as...

After a little more poking around, I found the trace leads to the source of Q207, an N-channel mosfet.  The gate is connected to pin 16 of the opamp.  Drain is connected to pin 7 of the opamp. I think I'm going to cross my fingers, and try replacing both the opamp, and the mosfet. Unless you...

R151 tests 1k C107 tests 1.15nf I have continuity back to a via just to the right of C26.  The trace then heads under U2L (vref?), and I cant seem to follow it after this.  It does appear there may be some minor corrosion hiding under there.  I assume its supposed to be connected to a pin on...

I tore it down today.  Something worth mentioning, is this board was particularly clean.  I dont see any signs of cap corrosion anywhere.  No discolored traces, etc Found some pictures of the trace routing between the VREF and opamp.  Traces all test good between them, and the surrounding...

If I'm really quick, I can pull up the battery meter before it goes back to sleep.  The meter shows as completely dead. Where is the PMU that reads the battery level?

I'm currently working on a Mac Portable, backlit. Its been cleaned, recapped, fresh battery installed, w/ SCSI2SD. System 7.1 installs fine, but as soon as it booted the first time after install, I get the message: "No battery reserve power remains. The Macintosh will go to sleep within 10...

Figured I should chime in again.  Here's my simple bracket for mounting the "Michael McMaster" 34-50 pin SCCSI adapter, and SCSI2SD v5b neatly into the original HDD tray of the Macintosh Portable.  Everything is mounted using standard #6 computer case screws...

Hi guys.  I just wanted to touch up a bit on 360alaska's great ideas for 3d printing parts for our machines.  I downloaded the STL for the Mac Portable foot, but I found the file has several errors.  Nothing huge wrong, just tiny gaps n such, which can cause some slicer weirdness.  Also, I found...