Ferrix97
Well-known member
Hello!
I recently acquired a Macintosh Portable M5120, when I power it from a brand new (and charged) lead battery, it runs fine until it tries reading from the floppy drive or it spins up the hard disk, at this point the machine goes crazy: sometimes it will freeze, sometimes it will go in a reboot loop or in a sad mac loop and other times it simply turns off.
If I plug it to my bench power supply (set at 7.5V 2A) the machine will boot from the hard drive or from the floppy drive without any problems. when running and charging the battery it draws about 1.6A, it I remove the battery, the current drops to less than 1A.
When the machine completed the boot process (and the battery is connected), I can disconnect the power supply, but after 15 seconds it will report a low battery and then shut down. If I plug the power supply back, the battery level quickly rises until it reports that the battery is fully charged (and the charging icon disappears).
The board has been fully recapped and washed. I also added a 1Meg resistor between pins 16 and 18 of the Hybrid IC.
should I replace the mosfets?, the IRF9Z30 is quite hard to find nowadays.
If I cannot fix the issue, I might end up using a modified version of the Portable PowerBook Power Supply, detailed here, with added protection and current limiting.
EDIT: The current prototype of the the Portable PowerBook Power Supply power the portable perfectly!, I can fit the batteries and the electronics in the battery bay and then route a wire from the modem port that plugs into the power connector on the back. Tomorrow I'll try hooking it directly to the battery contacts or to the power connector on the logic board. I can 3D print a cap to prevent plugging an AC Adapter when the Portable Power Supply is installed
I recently acquired a Macintosh Portable M5120, when I power it from a brand new (and charged) lead battery, it runs fine until it tries reading from the floppy drive or it spins up the hard disk, at this point the machine goes crazy: sometimes it will freeze, sometimes it will go in a reboot loop or in a sad mac loop and other times it simply turns off.
If I plug it to my bench power supply (set at 7.5V 2A) the machine will boot from the hard drive or from the floppy drive without any problems. when running and charging the battery it draws about 1.6A, it I remove the battery, the current drops to less than 1A.
When the machine completed the boot process (and the battery is connected), I can disconnect the power supply, but after 15 seconds it will report a low battery and then shut down. If I plug the power supply back, the battery level quickly rises until it reports that the battery is fully charged (and the charging icon disappears).
The board has been fully recapped and washed. I also added a 1Meg resistor between pins 16 and 18 of the Hybrid IC.
should I replace the mosfets?, the IRF9Z30 is quite hard to find nowadays.
If I cannot fix the issue, I might end up using a modified version of the Portable PowerBook Power Supply, detailed here, with added protection and current limiting.
EDIT: The current prototype of the the Portable PowerBook Power Supply power the portable perfectly!, I can fit the batteries and the electronics in the battery bay and then route a wire from the modem port that plugs into the power connector on the back. Tomorrow I'll try hooking it directly to the battery contacts or to the power connector on the logic board. I can 3D print a cap to prevent plugging an AC Adapter when the Portable Power Supply is installed
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