Portable Power Adapter

[westcoastech]

Hey guys

How hard do you think it would be to come by a Portable power adapter on its own, I would think pretty rare. Are any other power adapters compatible with the original Portable, are the plug sizes the same, voltage etc?

I have a chance to buy a Portable for $150 but it doesn't have the power adapter and as such it is unknown if it will turn on. It apparently worked when it was stored years ago, the battery is still installed on the inside (although most likely dead, hopefully it didn't leak but doesn't appear to have).

What do you guys think, is that a little expensive for a gamble on a Portable, I know they are rare although I don't really know that much about them, not really into collecting laptops but have wanted the original Portable.

Any help would be great, thanks.

 

[pintodave]

I picked up my Portable's original white power adapter (7.5V 1.5A) on ebay for $45 shipped, earlier this year. They come up fairly often, though not regularly, on eBay. I find Portable stuff at decent prices to be more of a waiting game than anything.

If you have a 5126 (backlit version), the powerbook 2.0a adapter will work. The 5126 actually has the input power rating at 2.0a, not the 1.5a of the 5120 adapter. I have had no ill effects using the lower rated adapter, though. I don't know how long it should take to fully charge the portable's main battery, but I would assume it's between 2-3 hours. I just leave mine plugged in overnight before doing anything with it.

 

[westcoastech]

Do you if the tip size changed for later PowerBooks or if they stayed the same? If I could find one with the same voltage and as much or more amps I would be fine, I tried looking at pics, it kinda looks like a standard plug, not sure if there is a good chance some other random adapter would fit or not (non Apple).

Not sure if this is the backlit version or not, what do you think about the price of $150 for a Portable that's a maybe it works maybe it doesn't?

 

[pintodave]

The powerbook 1xx power adapters/chargers use the same style and sized plug as the portable, so that part isn't a problem. The problem is with getting a power adapter of the correct rating. Due to the way the charging/power circuit is designed, using an AC adapter/charger of ANY amperage higher than the original specs will put the logic board at risk for further damage, even if the caps on the board are replaced.

Don't ever forget --- never power a mac portable with an adapter of any higher rating than the original! This is the #1 rule of thumb when working with the Portable.

As for the price, it depends on what it comes with, for that price. Does it have the bag, main battery, or anything else? $150 for a portable, when comparing to eBay prices, sounds like a great deal. But when it comes to realistic value, it sounds a little steep, being in unknown working condition.

99.99% positive that the board needs new capacitors. I wouldn't mess with powering it or anything else until the board has been cleaned and re-capped to remove any electrolytic capacitor goo. That stuff will eat away at the traces, vias, and surface mount pads. If the board has been with leaking caps for a long time, chances are you have a lot of rot going on and it will take some work to get going again.

If it has been powered by the wrong adapter in the past, several parts of the circuit are probably toast as well.

 

[westcoastech]

Hey man, thanks a lot for talking with me about this its totally appreciated.

It doesn't look like it includes anything else, no bag unfortunately and no adapter. It does have a RAM expansion card and 5 MB total. It does have the original battery but unknown if that works either. The batteries I suppose are hard to come by as well, especially in working condition for such an old unit. Can anything be done about that or do most people usually run it without the battery?

So using a power adapter that is the correct voltage but higher amperage would not be good? I had thought the unit would draw only as much power as it needed as long as the amperage as the same or more and if the voltage was a dead match, that's not completely true?

I suppose these computers had a pretty bad capacitor problem then? I have some of my machines logic boards recapped and some others are currently running ok in original condition. For these old portables you would recommend just going ahead and doing it before anything it was that bad eh?

Ya eBay prices and realistic prices are on two totally different planets, some people are asking $400-500 for Portables right now and some are in unknown condition or in need of service condition, not cheap.

 

[pintodave]

If it were me, and I absolutely love my portable (check out my revival thread), I would go for it.

Unfortunately, the portable cannot be operated without a good battery. Technically, you can connect a 6V adapter to the battery terminals and "simulate" a working battery, to get it going.

Technically speaking, the Portable is never actually being powered from wall power, even with the charger connected. It constantly/always pulls power from the battery, and the charger pretty much just sits by to replenish what is used.

The Portable will use all the amperage from the wall adapter that is can, not just what it needs. It's due to how the power/charging circuit is designed. There are several threads here about it, techknight is the master of Portable repairs and has been kind enough to provide us with the wealth of information he has attained by repairing these boards.

Due to the age of the Portable, it is certain that the caps are bad, and to avoid further damage, it is usually recommended not to use it with bad caps.

Should you decide to go through with the transaction, I recommend contacting the following people for logic board repairs:

uniserver - capacitor replacements (tantalum caps won't leak like the aluminum electrolytic ones do)

techknight - any and all other issues you may come across after the re-cap.

 

[pintodave]

If you are planning to get it, and it is a 5126 model, this power adapter will work, it is 2.0a that the backlit version is rated for:

http://www.ebay.com/itm/ORIGINAL-APPLE-AC-ADAPTER-FOR-POWERBOOK-100-140-160-180-/221135710032?pt=Laptop_Adapters_Chargers&hash=item337cb72750

If it turns out to be a non-backlit version, model 5120, this power adapter is what you will need.

http://www.ebay.com/itm/Vintage-Mac-Parts-NEW-Macintosh-Portable-Power-Adapter-M5136-/351200474376?pt=US_Vintage_Computing_Parts_Accessories&hash=item51c52df508

 

[techknight]

Since you have to pull it apart and recap it anyway, an easier way of going about this is take a Powerbook 1XX charger apart, and replace its leaking caps plus you can adjust the current output. 

 

[pintodave]

Interesting point. I didn't know you could do that. Is that being covered in the leaking ELNA caps thread?

 

[techknight]

the Sony chargers have 2 adjustments. one is Voltage, one is Current. 

You will need some kind of electronic load, or even resistive load to set the current output. 

 

[pintodave]

I will keep this in mind. It may come in handy. Is the Portable's white 1.5a charger the same way, though?

 

[techknight]

I never have taken one apart, but I dont see why it wouldnt be. If anything, it should be an earlier revision of the same design. Usually when an electronics design gets finalized, peeps usually stick with it unless there is a revision or two that needs made. 

Same with windows, or anything. its all built on top of a core that was originally designed 25+ years ago. lol. 

Same thing with electronics. Unless its an entirely new design, i dont see why they would change the design. 

the only time I have seen designs change is to achieve more efficiency, or the discontinuation of parts force change. I see the ladder more than the former. 

 

[pintodave]

That makes a lot of sense. Funny about Windows, it even feels like it's 25 years old sometimes lol

 

[techknight]

I know I am right about windows, I was ghosting some dells yesterday, and I was bored staring at the files. Noticed a few of them with 286 in the name. thats how I figured. 

 

[TheWhiteFalcon]

The NT kernel is about that age, yep. Good for software compatibility though, I've run stuff designed for 3.1 in 8.1 just fine. Of course Darwin isn't a spring chicken either.

Personally, I feel that's a good price for the Portable, even if it has issues.

 

[westcoastech]

Hey guys

Thanks a lot for all the responses, I am currently in talks with him about the shipping and trying to nail down a deal. Hopefully it goes through, will be a fun project.

Good to know about the power adapter as well, since I know at least for most modern computers you can use an adapter that has higher amps as long as the voltage is correct, example using an 85w MagSafe on a 13-inch MacBook.

Hopefully I can find one that isn't too expensive, those eBay listings are a huge difference, $10 for the backlit version and $50 for the non-backlit. Will have to wait until I get the Portable and see which one, $50 is quite a lot so hopefully if it is that model I can find another one. Otherwise as you said techknight I could get the adapter serviced as well and have the amperage changed at the same time.

As for the battery I suppose some just hook one up semi-externally from the laptop just to get it running. What was your solution pintodave for a permanent solution?

 

[techknight]

Well, modern computers the charge circuitry is regulated. the portable, it is not. battery consumes all it can from the charger. So the higher current the charger is, the more the battery will draw. Sometimes this can over-tax the charge controller circuitry. 

Bad bad bad design. thats why it was all revised in the PB100. 

 

[wilykat]

Why not cook up a mod that forces limit on charger so one can use any power supply and not worry about it melting due to overdrawing current?

 

[pintodave]

That sounds like a good question for techknight. For me, I rebuilt my original battery and use the original 1.5a charger with it. Even though the battery won't last long with limited use of the computer, I have been using it for the past six months or so and this time alone I found to be worth the $35 for the battery rebuild, even if just temporary until I forget to charge it one week...