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| Portable 5120 (non-backlit) always goes to sleep |
Posted by: mattsoft on 2022-06-14 08:49:09
Hi all - I picked up a Mac Portable and recapped the main board and am having an issue -- a story as old as time itself!
The Portable wakes from sleep just fine and will boot, but as soon as the Finder comes up, I ALWAYS get the "No battery reserve power remains...Good Night." and then it goes back to sleep.
The Portable is plugged in with a real (beige) Portable power adapter which is outputting 7.5V. The 6V lead acid battery is charging just fine and holding a charge well. The 9V battery is brand new and giving me 9V.
So I'm wondering if there is a broken trace in the battery/power sense circuit? I've been looking at the Portable schematics on the "HYBRID / POWER SUPPLY" diagram, and buzzing out the circuit and did find (and fixed) a broken trace from C17(+) to C110 -- the trace appears to run under the hybrid which is why I didn't see it when recapping. But that didn't help.
Is there an area I should focus on given the symptom above? I'm hoping it's not the hybrid itself, but any hints would be appreciated.
Thanks! |
Posted by: techknight on 2022-06-14 18:23:31
bad hybrid. If the ADC and charge indication signal traces to the PMGR are good, its a bad hybrid. |
Posted by: mattsoft on 2022-06-15 12:59:48
Well crap! That would suck. Just for giggles, I soaked the board in soap and water last night, then rinsed with IPA and let dry. Today when I power it on, it boots to Finder and then just locks-up -- no more battery message. I'm going to try soaking it some more and see if it changes. If I had an ultrasonic cleaner, I'd use that, but... any recommendations on a cleaning/soaking liquid? Should I try soaking it in a bath of IPA instead of water? |
Posted by: desertrout on 2022-06-15 13:59:42
Well, if you're feeling adventurous... IPA scrub with a toothbrush, dishwasher (quick cycle, no soap), might need another IPA scrub after that, then bake in oven at lowest setting for 15-20 minutes (like, 170F). You could even try reflowing some of the components on the hybrid as well as the hybrid's legs (at least any scuzzy looking ones near the caps). But if techknight is correct and hybrid is indeed bad you're hooped. (Until his hybrid replacement project with androda is ready for market!) |
Posted by: mattsoft on 2022-06-15 14:29:47
I'm adventurous! I have the board soaking in hot soapy water now. Will scrub it later. I don't want to send it through our dishwasher and potentially leave heavy metals in there. But I'll scrub, scrub, scrub that board and see if anything changes. The hybrid LOOKS so clean (component side), but who knows what lurks underneath. |
Posted by: techknight on 2022-06-15 16:07:13
Well crap! That would suck. Just for giggles, I soaked the board in soap and water last night, then rinsed with IPA and let dry. Today when I power it on, it boots to Finder and then just locks-up -- no more battery message. I'm going to try soaking it some more and see if it changes. If I had an ultrasonic cleaner, I'd use that, but... any recommendations on a cleaning/soaking liquid? Should I try soaking it in a bath of IPA instead of water?
Does it freeze before the desktop or at the desktop? usually thats caused by failure to communicate with the SCC. |
Posted by: mattsoft on 2022-06-15 18:00:01
Does it freeze before the desktop or at the desktop? usually thats caused by failure to communicate with the SCC.
So I'm booting from a FloppyEmu and loading the System 6.0.8 Disk Tools. It gets to the desktop -- the mouse cursor actually moves up until the desktop is loaded, then the cursor freezes wherever it was at when it finishes loading. Strangely, the FloppyEmu read activity continues to blink, but the track/side status does not change. If I hit reset on the side, it cleanly reboots and does the same thing over. But yeah, the desktop appears to be loaded. I need to try to boot from SCSI too and see how that goes. I'll try again tomorrow after the board is dry. Maybe my "aggressive" cleaning will change the symptom again. |
Posted by: LaPorta on 2022-06-15 18:26:55
Try an actual floppy? |
Posted by: mattsoft on 2022-06-15 19:22:57
Try an actual floppy? Guess I could, but the FloppyEmu boots fine on every other Mac using this image. I've also tried a System 7 image and it does the same thing on the Portable. |
Posted by: mattsoft on 2022-06-16 08:12:25
Well, after a thorough cleaning (w/scrubbing), I still have the same problem. Boots to desktop and then freezes. Tried with a System 6.0.5 floppy and real FDD connect and same thing. There's no electrolytic capacitors near the SCC, so assuming that IC works, maybe there's a damaged trace/component from elsewhere near where a leaky cap was that leads to the SCC? So I guess I'll start probing around the SCC and see if something jumps out. |
Posted by: LaPorta on 2022-06-16 08:47:22
Best of luck, man…this is a tough one! |
Posted by: mattsoft on 2022-06-16 12:22:12
Just hooked-up a RaSCSI to the external SCSI bus and booted a 6.0.8 image and had the exact same symptom: system locks-up when desktop is loaded. ERG! So I'm going to rule-out anything with the SWIM for now. |
Posted by: 3lectr1cPPC on 2022-06-16 13:19:48
Have you checked the power rails off the hybrid? |
Posted by: mattsoft on 2022-06-17 08:49:55
Have you checked the power rails off the hybrid?
Just did. They don't look right, I'm not finding +12v or -5v on any pins:
4 1.5v
8 3.9v
11 5v
16 7.5v
17 7.5v
18 5.2v
21 7.5v
25 7.5v
31 -1v
39 5v
41 7.4v
51 1.2v
52 1.2v
61 7.4v
62 4.7v |
Posted by: 3lectr1cPPC on 2022-06-17 08:55:16
Not sure what's supposed to be what on a working hybrid, @techknight will have to confirm that. It's supposed to generate +5, -5 and +12 I believe, might be wrong though. (source: https://68kmla.org/bb/index.php?threads/mac-portable-hybrid-combine-forces.40175/page-2#post-438196)
The good news is that great progress on a modern replacement is being made, and should hopefully be available soon. |
Posted by: mattsoft on 2022-06-17 09:01:22
Yeah, maybe I just set this thing aside until then. Doesn't seem worth troubleshooting until it has a known working hybrid in it. |
Posted by: techknight on 2022-06-25 04:23:18
Yeah, maybe I just set this thing aside until then. Doesn't seem worth troubleshooting until it has a known working hybrid in it. Boot it from System 7. Does it lock up before it gets to the desktop? |
Posted by: techknight on 2022-06-25 04:24:06
Not sure what's supposed to be what on a working hybrid, @techknight will have to confirm that. It's supposed to generate +5, -5 and +12 I believe, might be wrong though. (source: https://68kmla.org/bb/index.php?threads/mac-portable-hybrid-combine-forces.40175/page-2#post-438196)
The good news is that great progress on a modern replacement is being made, and should hopefully be available soon.
Yeah we just fixed the last standing bug with the hybrid last night. afaik, the replacement is fully functional. |
Posted by: mattsoft on 2022-06-25 08:47:44
Boot it from System 7. Does it lock up before it gets to the desktop? No, locks at the desktop. |
Posted by: Johnnya101 on 2022-06-25 11:27:07
Yeah we just fixed the last standing bug with the hybrid last night. afaik, the replacement is fully functional. That is great to hear. Can't wait to see the thread on it. |
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