| Click here to select a new forum. |
| Programmer's Switch on Mac Portable not working |
Posted by: NJRoadfan on 2013-08-31 18:34:04
Any item why?
I installed MacsBug 6.5.3 to test it out. The debugger installs on boot, but pressing the Programmer's Switch does nothing.
|
Posted by: nvdeynde on 2013-09-01 01:39:44
These switches often go bad. Replace it: anyone from another Mac Portable or Compact Mac will do as they are identical.
I don't know if new switches like these are still for sale.
|
Posted by: RickNel on 2013-09-03 16:45:35
I'd first be checking whether the physical contact-switch is the problem. They typically contain a tiny spring-metal dome that can get deformed or broken in some circumstances, or the action can be blocked by a speck of dirt of some kind. First check the on-off operation with the continuity tester on your multimeter, and if it fails look for a mechanical reason. If it needs to be replaced, the actual switch mechanism is quite generic, but it is also possible to wire in a non-standard contact switch if you have to.
IIRC there is also an isolation capacitor near that switch, which I would look at next if the switch appears to operate correctly.
Deeper than that... :-/
Rick
|
Posted by: NJRoadfan on 2013-09-03 17:00:46
The isolation capacitor was replaced along with the rest of the caps. The reset switch works fine so I found it odd that the programmer's switch didn't. I'll have to check it again to see if its closing.
|
Posted by: NJRoadfan on 2013-09-04 21:10:56
I can confirm the switch contacts are working. Continuity test confirms its closing when pressed.
|
Posted by: nvdeynde on 2013-09-05 04:44:17
Are the 2x small SMD capacitors near the switches soldered well: test them and check for lifted traces as well. Otherwise check the circuit from the switch to the next component for broken traces.
Anyway it's not really a big deal that the programmer switch doesn't work as you don't need them when the logic board has been recapped.
I never had to press the reset/interrupt switches again after recapping my Mac portables while before it was always a pain and guess after how many times it would start...
|
Posted by: NJRoadfan on 2013-09-05 05:15:24
The reset switch works fine. Testing the programmer's switch isolation cap, I get continuity from the negative terminal to one of the switch terminals. The positive terminal gets continuity to a pin on the "MISC GLU" chip as expected. When power is completely removed from the machine, I have to power cycle it for a good minute to reset the PMU and clear the instant sad mac despite being recapped.
|
Posted by: nvdeynde on 2013-09-05 08:27:12
When power is completely removed from the machine, I have to power cycle it for a good minute to reset the PMU and clear the instant sad mac despite being recapped How do you power cycle it ? If you have a working battery this shouldn't be necessary as when you remove all power, the capacitors drain quickly and then the PMU is automatically reset in a matter of seconds. You have a rebuild battery I assume ?
What sad mac code do you get ?
I use my Mac Portables regularly but never leave the main battery installed. However they always power on immediately after inserting the battery and pressing the keyboard.
I have seen Mac Portables from fellow collectors that used the Mac Portable without rebuild battery on a heavy DC PSU and got the logic board damaged this way ( PMU errors, unstable, often not willing to power on,... ).
We also never know what previous owners did with the computers before we got them...
|
Posted by: NJRoadfan on 2013-09-05 12:04:26
I'm using a rebuilt battery and the stock 1.5A power supply. Errors are usually 0000 13xx or 0000 17xx, neither of which actually come up as valid codes. Once the PMU finally resets, I don't have any problems until power is removed again by taking out the battery.
|
| 1 |