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"Suspicious" power adapters

CompuNurd

CompuNurd

68000
Got these in the mail today, $20ish for the lot. Supposedly dead, so going to reference and replace capacitors to see where that takes me.

I better keep them in a box at night, since they are acting suspicious :p

I just need a way to open them since I don't have a vice.

image.jpg

 
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Just a question, if they are dead, or "suspicious", I am guessing it is capacitors? What else could it be, they're power adapters.

 
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sus·pi·cious
səˈspiSHəs/
adjective
 




  1. having or showing a cautious distrust of someone or something.
    "he was suspicious of her motives"
    synonyms: doubtful, unsure, dubious, wary, chary, skeptical, distrustful, mistrustful,disbelieving, cynical




    "she gave him a suspicious look"






       








    • causing one to have the idea or impression that something or someone is of questionable, dishonest, or dangerous character or condition.
      "they are not treating the fire as suspicious"
      synonyms: disreputable, unsavory, dubious, suspect, dishonest-looking, funny-looking, slippery; More




       






         







    • having the belief or impression that someone is involved in an illegal or dishonest activity.
      "police were called when staff became suspicious"














 
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they could have saved the mystery.

Definition of MYSTERY
 
a :  a religious truth that one can know only by revelation and cannot fully understand
 
b :  any of the 15 events (as the Nativity, the Crucifixion, or the Assumption) serving as a subject for meditation during the saying of the rosary (2) capitalized :  a Christian sacrament; specifically :  eucharist
 
c :  a secret religious rite believed (as in Eleusinian and Mithraic cults) to impart enduring bliss to the initiate (2) :  a cult devoted to such rites
 
2
a :  something not understood or beyond understanding :  enigma
 
b :  a private secret
 
c :  the secret or specialized practices or ritual peculiar to an occupation or a body of people <the mysteries of the tailor's craft>
 
d :  a piece of fiction dealing usually with the solution of a mysterious crime
 
3
:  profound, inexplicable, or secretive quality or character <the mystery of her smile>
Click to expand...


and just said ( works ) ( does not work ) ( sometimes works )

 
CompuNurd said:
Just a question, if they are dead, or "suspicious", I am guessing it is capacitors? What else could it be, they're power adapters.
Click to expand...
If it is just a dead PSU, then it should be dead caps. But in seeing the video I notice that there are 2 regulators and a fuse. The fuse can blow early on but I doubt the regulators would go. When you recap the PSU, test it with a multimeter. It should be within 1 volt and .5 amps of its rated output. I prefer to use an analog meter for this, as if there is flutter in the circuit, you can see the needle shake. The needle should be rock solid still. If there is a flutter, it could be an aging regulator or the outside environment (like your refrigerator turning on and causing a power dip in the house), you need to figure it out.

There are two Pots (Potentiometers, aka. variable resistors) on the PSU Daughter Board. One adjusts voltage, the other adjusts the amps. But, in adjusting one, you also affect the other, so you need to get it in a balance of the two as close or on rated output as possible. Use plastic tools for this. And if possible, use two meters at the same time to measure each output separately.

I know you can do this. Compared to a logic board, it should be easy. Easier than replacing the caps on a LC PSU like you and I did in the past.

Good Luck.

 
Maybe you can regulate them down to 1.5 amps and sell em to portable users, There is a market for such too!! I'd buy one from you. :) Portable users need 1.5 amps. 1500ma MAX.

 
More questions, and my $.02:

My multimeter has a milliamps up to 200mA, so I might have to go get an extra analog one, plus it won't even give me mA reading on a battery. My multimeter is a basic Radio Shack model, and it's digital.

Are the capacitors the same in all units, or is there a different revision with different capacitors?

I found a good way to open them that isn't too hard on the plastic: take a rubber mallet, and hammer the brick all the way around. Don't be too hard on it though, or you will chip the plastic. Just smack it at the seal where Ferrix used a vise, and you can crack it open! Be careful though, I damaged my work surface where I had to hammer the corners, so a concrete floor or block would be great here.

 
You can get a 20a max multimeter at harbor freight for a couple bucks, Mallet works good with portable battery packs as well !

 
One more: what's the line filter capacitor voltage? It just says 47uF, I don't see a voltage. I am guessing it's 250V?

 
PowerBook 100 and portable are only machines worth keeping around all others have plastics that are deteriorating into crumbs. Pb 140 to pb5xx series all will be pile of parts and crumbles of plastic hunks soon. What a crying shame too.

 
uniserver said:
PowerBook 100 and portable are only machines worth keeping around all others have plastics that are deteriorating into crumbs. Pb 140 to pb5xx series all will be pile of parts and crumbles of plastic hunks soon. What a crying shame too.
Click to expand...
My PB180's plastics are just fine, I don't notice any real issues...

 
Someone should start a business making and selling new replacement parts for old machines (like cases and fly back transformers). Someone is already making the floppy drive gears, why can't we start making boards, cases, etc? Could make some money doing that since no one else does it.

Wait....

I'll be right back :)

 
" i don't have any brittle plastic issues with any of my power book 140 - 5xx "

Ohhh don't worry,  its inevitable.  

 
usually the main filter cap is always good, just replace the brown leaky ELNA ones.

the only problem you may find during the process is a corroded circuit board, just spend more time cleaning it and sealing it, if necessary.

As for current limiting, there should be a trimmer on top of the controller board, see my videos, just turn it down, you should make a cable adapter that enables you to measure the current while plugged to a load. let me know if you need more informations!

make sure you don't short the power supply with the multimeter while checking current

on all the brick I repaired, none of them needed adjusting, since the powerbooks will accept a wide range of voltages and the fact that the voltage dips down while under load

https://www.youtube.com/playlist?list=PLvK52TiAHHJpKxeQjfkHBZjSKctZQuidU

uniserver, if you need Mac Portable bricks, just open one of the PowerBook ones and tweak the trimmer inside to adjust the current limit.

Should i do a video about that too? but I don't have a Mac Portable (Yet... still looking for one...)

 
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