68kMLA Classic Interface
This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.
| Click here to select a new forum. | |
| Powerbook G3 Pismo seemingly dead? | |
| Posted by: EvieSigma on 2024-02-02 15:48:14 I recently got a Pismo (with a 500MHz PPC7410 upgrade!) but it's...seemingly completely dead? Plugging in my 45W yo-yo adapter does absolutely nothing, neither does the key combination for a PRAM reset. Is something fried? Do I need a different power adapter? | |
| Posted by: mg.man on 2024-02-02 15:51:25 Disconnect the PRAM battery and try to power it up? 
PowerBook G3 Pismo TroubleshootingThe Pismo looks like the Wallstreet and Lombard, but has a Firewire 400 port. Troubleshooting is fairly straightforward.
www.ifixit.com
| |
| Posted by: EvieSigma on 2024-02-02 19:37:00 I did try that...it didn't work, same symptoms as before. | |
| Posted by: greystash on 2024-02-02 21:10:02 The 500Mhz CPU is nice! They're quite hard to find now. I'm pretty sure the power cards fail on the Pismo often. I had the same issue, no power or signs of life but after replacing the power card from another Pismo (working) it booted normally. It would be worth re-capping the machine as this is probably where the problem is coming from. Trying another power adapter is a good place to start, otherwise either a new power card or re-capping might bring it back to life. | |
Posted by: joshc on 2024-02-02 22:23:42It would be worth re-capping the machine as this is probably where the problem is coming from.Is it? I’m not aware of these using electrolytic capacitors. | |
| Posted by: MacUp72 on 2024-02-02 23:41:21 I had a Pismo with a standard G3 400 Mhz daugtherboard with booting problems, I carefully removed the board and inspected it..two little pins were ever so slightly crooked, I carefully bent it back..it never booted again..temper temper I hate those connector boards, the latest 500 mhz models had better ones  | |
Posted by: mg.man on 2024-02-03 02:40:48I did try that...it didn't workBummer. I have had to replace the "power in" (DC jack) board on one of mine. Not sure if this is the exact one, but similar to this :  | |
| Posted by: EvieSigma on 2024-02-03 09:42:14 The only one of those I found on eBay is $40 shipped so I hope I don't need one...I can try swapping the other power board from my working Lombard into the Pismo, though. | |
Posted by: mg.man on 2024-02-03 10:05:18I can try swapping the other power board from my working Lombard into the PismoNot sure they are interchangeable? Perhaps someone following this thread will know? 🤔 | |
Posted by: greystash on 2024-02-03 15:01:12Is it? I’m not aware of these using electrolytic capacitors.There's at least one on the logic board near the PCMCIA slot, and three on the underside of the power card 😕 | |
| Posted by: EvieSigma on 2024-05-18 12:19:12 It took me a couple months but I tried swapping the DC-in board and the Pismo is still dead. I guess the next step would be that power card? | |
| Posted by: Byrd on 2024-05-18 23:29:04 Common fix for many here with dead Pismos over the years has been to pop up the keyboard and disconnect the PRAM battery. Failing that, reseat the CPU daughter card, RAM, contact clean all connectors | |
| Posted by: beachycove on 2024-05-19 08:19:23 Yo-yo power adapters in my experience are very prone to failure. The wires break at the flex points, especially at the adapter end, in where the sun don’t shine and the thing is nigh impossible to repair. I’d try another adapter or test the thing before resorting to further, possibly unnecessary surgery on the Pismo. It ought to run from any adapter with the same jack, i.e., one from the Duo series, the 3400, the Wallstreet and obviously the Pismo itself. I’d maybe remove battery and optical if working with a older adapter, as it would presumably be marginal. The rest might be okay — though I find that the caps are starting to go in Wallstreet adapters these days. | |
Posted by: EvieSigma on 2024-05-20 15:04:44Yo-yo power adapters in my experience are very prone to failure. The wires break at the flex points, especially at the adapter end, in where the sun don’t shine and the thing is nigh impossible to repair.The yo-yo works fine booting my Lombard and my Wallstreet so it's gotta be the Pismo that's the problem. | |
| Posted by: mari3311 on 2024-05-24 02:42:02 For sales purposes, I had a professional replace 9 Pismo PC750 400MHz CPU daughter cards with PPC7410 500MHz chips. Five of them were PC750s that were originally working normally, but the other four did not start even if the PRAM battery was removed, as mg.man said. My Pismo, which works fine except for the CPU daughter card, doesn't work even after I remove the PRAM battery. At first, I thought that the CPU chip was bad, and that it would start up if I replaced it with a PPC7410 500MHz chip. I thought so, but the 4 faulty cards that were returned to me were still faulty. * So, I bought a normal PC750 400MHz CPU daughter card at an auction and tried replacing the ROM chip. (I used the same type of low temperature solder as ChipQuik for removal)  Pismo (PPC7410 500MHz) started successfully. (Of course I changed the chip resistance settings on the card) When I ported the ROM removed from the first card to the second "faulty PPC7410 500MHz card," it started working as well. (wonder!) After repeated porting in this way, out of the four defective CPU daughter cards, only one did not start up until the end. As a result, I ended up with a total of 8 Pismo (PPC7410 500MHz) daughter cards. * If the results are not good even after following the advice of others, you may want to try replacing the ROM chip. The method to replace this ROM was inspired by this 68KMLA forum's post about Color Classic repair. | |
| Posted by: EvieSigma on 2024-05-27 12:20:07 Yeah, tried replacing the power card, and now with both a new power card and a new DC in board it's still faulty, so I gotta wonder if something is wrong on the CPU card. | |
| Posted by: thirdbanana on 2024-09-06 11:00:48 Are those ROM chips proprietary? | |
| Posted by: imactheknife on 2024-09-07 06:32:48 You also have to make sure the cpu card is actually “in”. I thought my pismo was dead. Someone suggested pressing harder on cpu card where sockets meet. So i did, but was scared to break it. It worked. The cards have to mesh properly and be connected firmly or no signs of life too | |
Posted by: mari3311 on 2024-09-07 09:42:31Are those ROM chips proprietary?The ROM chip I used for the port was a ROM chip from an original CPU daughter card. | |
| 1 |