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Found 11 results

  1. North Hedge Ned

    Macintosh Portables Dead

    Hello, I know that there is much discussion around the Mac Portables and their woes with powering up. So much information, in fact, that I have become lost in it all and have no idea where to start. So, if I may, some simple questions, and some directional guidance required. I have several of these beasties and they all do not seem to start up. Some don't boot at all, some boot then power off, some boot, show a mouse, and the drive tries to spin up then shuts off. One I had boot and went straight to sad Mac. It even ran off the replacement battery that I had in it (6v 5maAh lead-acid, new, fully charged), in this sad Mac state. However when I disconnected power and tried again, it would not boot. I always had the cutoff switch engaged when trying to boot from the main battery. With adapter connected (a real Portable Adapter) I am getting the 7.1 v reading at the main terminals inside the computer with the cutoff engaged. With my battery connected, I get the same. When I activate the cutoff (as in have the switch open) and my battery connected, I am reading the 6.3v of the connected battery at the terminals. Questions: 1. Must the 9V battery be installed for the unit to function properly? 2. If I were to pul the board, is there a concise step by step with photos of how and what to test with my multi-meter? Would this resource also tell me what to replace and how? I do not have the means to remove old solder. Looking for guidance and a resource to dive into. I ultimately wish to sell these things, and suspect that the cost to fix is more than recovered by the sale of a functional unit vs a dead one. Thank you all in advance! Paul
  2. redruM69

    Mac Portable troubles

    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 seconds to preserve the contents of memory. Good Night." And then it sleeps. Waking it back up just gives the same message, and it cycles again. Booting a System 6.0.8 floppy works fine, as I assume it does not monitor the battery. The battery is charging correctly, showing ~6.2v alone, and ~7.3v if the AC adapter is connected. I have also tried a bench supply @ 6.5v to eliminate the battery being part of the equation. I haven't torn it down again just yet. I dug around and saw some older posts mentioning diagnosing the hybrid chip for a somewhat different, but related issue. Is the hybrid where I should start? Any additional tips?
  3. Hi all, Picked up a Mac Portable 5120 (non-backlit) last week; before powering it up, I removed the logic board, removed the caps from it - all of them, except the tantalum cap on the hybrid board - cleaned the board, replaced the caps, and got a new black 6v 4.5ah brick battery. Putting it all back together, it won't boot off of the battery alone - the screen flickers, and it either hangs on a flickering mouse-pointer screen, or flips over to the chimes of death. With the original Macintosh Portable power adapter and new battery connected, it will boot 90% of the time. When it falls, it simply does nothing. Based on previous threads here, I'm suspecting the hybrid board. I did find one bad trace on there, which I have bridged, but no change. Wondering if anyone here has any ideas to help narrow down the next vector of attack. I want to test continuity on all of the hybrid board traces, but I lose some of them beneath ICs.
  4. I am unable to power up my iMac G3. I opened up the case and pressed the CUDA button and it powers up. However every time I switch the mains to off I have to redo it again. Is something faulty? I had the PRAM battery removed by the way.
  5. Since this is absolutely the place to contemplate this question, I've been thinking about how to make my Wallstreet mobile again. I had a thought: What if you took the innards out of an existing dead battery pack and installed a cheap USB power bank in the case and used it in the slot? Could you run the machine with just the power leads connected, or would it complain if it didn't see anything connected to the charging pins? Would the machine be able to tell the level of charge just from the power output? Basically, does anyone have a schematic for the charging system I can review before I spend any money? I look forward to hearing your thoughts. EDIT: By the way, has anybody used these guys? http://laptoprescue.com/Powerbook-Battery/
  6. Hi all, excited to be a new member. My friend and I have been debugging a recapped 5126 lately and are looking for some advice. Once again this machine was recapped some time ago The machine is in OK shape overall with a well-behaved 40MB hard drive. Unfortunately, leakage from the three caps under J13 (left-hand kb/trackpad port) took a toll on the circuit board. We've recently bridged two pins of J13 that were attached to broken traces over to their cousins on the other side of the board. Also, I just now finished wiring the interrupt switch directly to the Misc GLU to work around a rotten via just above RP201. The board has a flaky SWIM. There is a replacement on standby. However, we suspect the power regulation may also be off, and this may have caused the SWIM to break in the first place. So we'd like to fix the power first before we exchange that chip. The problem is similar to the behaviour discussed in this thread from 2015. Plugged into the wall and with the battery installed, the system runs well enough, although some screen flicker occurs when the drive spins up. Unplugged, the battery meter shows the power plunging very quickly. It takes about 15 seconds or so before the computer gives up the ghost and shuts down altogether. The thread just linked suggests to me that bad continuity in the region south of J13 can cause problems like these, and given all of the continuity problems seen so far in that area, I wouldn't be surprised if more continuity issues were at fault, so it seems useful to check for that first. The thread suggested measuring continuity between C26 and pins 14/15 of the op-amp U1M, but those seem to be fine. What else might be worth probing? For what it's worth, we're using the original charger and a replacement 6v sealed lead-acid battery of the usual kind. Thanks for any help! --Tom
  7. Dear members I just purchased a Quadra 950 and it arrived safe and sound. The seller claimed that the power supply only clicked. My 4 year old daughter turned the key while just after I pressed a power button on the front facing panel and there was a chime, a loud healthy fan and a power light. Now, I have no monitor to check and there is no HD. Is this enough to confirm the machine works or should I ideally try something further. There also appears to be a 601 PDS card and a very large card that I suspect is a video card and gobs of RAM. Any advice would be appreciated. Many thanks! —Alex
  8. zuctronic

    Macintosh Portable Power Issues

    So I recently acquired a Mac Portable. As soon as it arrived I took it apart, re-capped the motherboard and hooked it up to a replacement battery. Everything was going well, actually no issue at all last night. I was able to mount some Appletalk volumes and play some games, it seemed pretty stable. This morning I decided to break open the original apple battery and toss my new cell in there. While testing this configuration, I accidentally hooked up the battery with reversed polarity... I know, this was dumb. Now I'm having issues again. Here are the symptoms: 1. Will not power on at all without wall charger plugged in. 2. Randomly crashes when doing anything. 3. It will go to sleep, but when it wakes up it either crashes with a crash chime or it just reboots. 4. System 6 "battery" meter shows battery slightly above middle charge all the time now (I doubt its accuracy!) 5. When I try to change the date, the system crashes / reboots. Any ideas? Could it be just a fuse? Is there an easy way to troubleshoot this without a meter? Thanks in advance! I hope I can get this back to life again...
  9. Hi. I bought a G4 Cube from the bay a while ago, and it currently has some issues maybe you guys can help me with. The Cube is pretty much a stock one, and all it does is: It powers on and shows the apple boot logo / plays the bong and even starts to load the OS. All ok up to here right? Thing is, as soon as I plug or unplug something on the (only working) USB port, it restarts. The other USB port is damaged (!!!!). If I turn it on with something already plugged in, it works, but it seems that the USB port hasn't got enough power to deal with a HUB, a keyboard and a mouse, so I can't really install a new OS onto it. Should I remove the damaged usb port? I heard somethign about a power board going rogue as well? Help!
  10. I just bought a Studio Display (M4551), with no power adapter and unfortunately this kind of adapters could not be found in my area. I've seen few items on eBay, but they were too expansive and including shipping to my destination it would have been more than 3 times more than the cost of the display itself. So I was thinking of finding some alternative or using iBook power adapter which has the same output, but I can't find information on the polarity (positive/negative) of the display's power cord. Polarity isn't mentioned on the original power adapter. Does anybody have this kind of adapter to check the polarity? Thanks in advance!
  11. Hi everyone! When I was younger the main computer in my family was a tray loading Bondi iMac running 8.6. It was used for hours each day for at least ten years (that's a conservative guess, it was very probably longer). A couple years ago it started having a minor issue. The power button needed to be pressed two or three times to get it to boot. Other than that everything was working great. One morning I got up and heard from a sad family member that the iMac wouldn't start up at all. No chime, no lights... nothing. It's currently sitting in my cold, lonely closet, and after reading what some of the people on here can do/have done I'd like to take it out and try to revive it. Given the computer's history my suspicion (what I thought when it died too) is that the power button broke. I don't have access to a keyboard with a power button so I can't test that for sure. My question is, how does one replace an iMac power button? And, if that doesn't work, would the next logical idea be looking at the power supply itself? Is there something I don't know that I should know? Thanks!