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Macintosh Portables Dead
Posted by: North Hedge Ned on 2019-05-17 07:38:23 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
Posted by: LaPorta on 2019-05-17 08:24:08 Paul, i am am not certain what you mean by “it even ran off the replacement battery” - All Portables MUST run off their battery. The power adapter is only used to charge it. Second, are you 100% sure it is a battery that is good for a Portable? The thing shutting down with HD spin up sounds like too much of a current draw on the battery. Certain batteries can only deliver so much current at a time, despite voltage rating (witness an “only” 12 volt car battery turn over that huge motor - much current is supplied instantly). I had a 6V for my Portable that didn’t work, and only once I got a proper replacement was it good. Third, did you re-cap the board? Photos would also be helpful.
Posted by: North Hedge Ned on 2019-05-17 10:02:08 Thanks LaPorta, “it even ran off the replacement battery” - by this I mean that the unit continued to be powered when I unplugged the AC adapter. In the unit I was running my 6V battery. I think that this batter is good. 6v 5mAh, same kind in my kid's electric ride'em car. In fact, here is the Amazon link: https://www.amazon.ca/dp/B00NR5NGRE/ref=cm_sw_em_r_mt_dp_U_QIU3Cb4KCR4R3 Third - I have not recapped. I know about it, but I have not found a concise "how to" and what parts to use, and where to get them. Any ideas? Thanks
Posted by: MOS8_030 on 2019-05-17 10:44:37 Yes, the Portable needs a good 9V battery to be installed. I use this lead-acid battery. It will fit inside the portable, and trimmed down a bit can be fitted into the original battery case. Although theoretically the battery you have should work as well. It is likely your Portable will need to be recapped to some extent. If you do a forum search you'll find several threads relating to recapping Portables and there are several members here with specific Portable experience. Perhaps they'll participate in this thread.
Posted by: LaPorta on 2019-05-17 10:53:21 Looked at the specs of your battery, it had the same issue the first I used did: fairly low initial max discharge current. The above battery MOS used, and the one that I used down here: https://www.batteriesplus.com/battery/sla-sealed-lead-acid/6/hawk0809=0012 Are better suited for the Portable. As for the capacitors, I made a list I can get to you from home when I get there.
Posted by: MOS8_030 on 2019-05-17 12:08:36 Looked at the specs of your battery, it had the same issue the first I used did: fairly low initial max discharge current. Ah, good point. Also I see the price has gone up since I purchased mine. (It's 20 years old and long dead.)
Posted by: LaPorta on 2019-05-17 12:47:03 Oh I didn't mean yours: your battery was probably a great replacement, I meant the one that he initially had used at the start of the thread.
Posted by: MOS8_030 on 2019-05-17 15:11:05 Oh I didn't mean yours: your battery was probably a great replacement, I meant the one that he initially had used at the start of the thread. Yes, I understood that. I meant you're probably right about his battery.
Posted by: LaPorta on 2019-05-17 19:28:36 Here are the Portable capacitors, per my hand-written notes at home: Portable Capacitors: C2 - 100µf, 25V - Radial C3 - 220µf, 25V - Radial C4 - 1µf, 50 V - Surface Mount C5 - 1µf, 50V - Surface Mount C6 - 100 µf, 25V - Radial C8 - 470µf, 25V - Axial C9 - 47µf, 16V - Surface Mount C10 - 47µf, 16V - Surface Mount C11 - 47µf, 16V - Surface Mount C14 - 10µf, 16V - Surface Mount C15 - 1µf, 50V - Surface Mount C16 - 470µf, 25V - Axial C17 - 47µf, 16V - Surface Mount C18 - 100µf, 25V - Radial C19 - 100µf, 25V - Radial C20 - 470µf, 25V - Axial C22 - 47µu, 16V - Surface Mount C24 - 1µf, 50V - Surface Mount C25 - 47µf, 16V - Surface Mount C26 - 47µf, 16V - Surface Mount C27 - 47µf, 16V - Surface Mount C28 - 47µf, 16V - Surface Mount C116 - 10µf, 16V - Surface Mount Capacitors behind the LCD: C11 - 220µf, 10V - Radial C23 - 10µf, 16V - Radial
Posted by: Bolle on 2019-05-17 20:49:04 You are going to have to strip out the logicboard and hook up the battery terminals to a bench powersupply (you have to do this the correct way or you are going to kill components on the board) to be able to do any useful troubleshooting. Replacing the caps and cleaning the board really good is obligatory before any further troubleshooting can take place. Look up techknights youtube videos on the Portable. They are a very good starting point. Check for broken traces around the Hybrid and in all places where caps are sitting. It’s common that stuff breaks around there.
Posted by: North Hedge Ned on 2019-05-19 09:16:26 Thank you all for your input - it certainly gives me a lot to test and attempt to solve. Thanks again. Will post my findings and success if you are at all interested. One of the units is a pre-release unit so that may be my first one to work on. It has a serial number, but a big bold sticker inlace of the usual label that states that the unit is a demonstration unit only and final release product will meet the FCC codes. When I get a glimpse of it inside would you be interested in posts along the way? Cheers!
Posted by: LaPorta on 2019-05-19 14:03:21 Two things: 1. Absolutely would love to see your progress! Please keep us updated. 2. I'd first work on one of the others. Why potentially bungle a prototype while learning?
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