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   Appears bricked, is there hope?
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   Author  Topic: Appears bricked, is there hope?  (Read 2664 times)
starhawk
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Appears bricked, is there hope?
« on: Apr 26th, 2011, 12:05am »
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Hi all! I'm starhawk, and I'll be your pesky n00by today.
 
I have a Psion Organizer II (labeled as a model XP), given to me by my father some years ago. Recently I stuck a 9v battery (transistor battery to you old-timers, and I think PP3 in Europe?) in there to see if it would still turn on.
 
No joy.
 
The display remains blank no matter what I do. I'm rather afraid of disassembly, but it's not that hard I'm willing to try. Please note that I'm bloody worthless (or close to it) with a soldering iron.
 
I will also say that this battleworn Organizer II has significant cosmetic damage, but it only has two issues more major than that. Apparently someone took it apart before, because it's got pointy screw ends poking up the keypad label. Also, the spring from the battery clip is long gone; I've replaced it for now with a bit of modern magic, aka polystyrene foam courtesy of a CD-R cakebox cushion.
 
If anybody can give me pointers as to how to go about diagnosing the fault, that would be wonderful. If, on the other hand, someone is willing to offer me theirs (in exchange or otherwise) that would be amazing. Please note that I'm a poor fella so we'd have to talk money a bit first.
Mikesan
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Re: Appears bricked, is there hope?
« Reply #1 on: Apr 28th, 2011, 12:26pm »
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If you have tried everything - the PP3 fits with the smaller, 'male' connector in first/innermost, then take it apart - CAREFULLY.  You might see something obvious.  N.B. those keys will go everywhere, if your'e not careful
starhawk
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Re: Appears bricked, is there hope?
« Reply #2 on: Apr 28th, 2011, 6:51pm »
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How would I take it apart?
Boris
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Re: Appears bricked, is there hope?
« Reply #3 on: Apr 28th, 2011, 11:19pm »
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Disassembly & reassembly instructions can be found in the FAQ.
« Last Edit: Apr 28th, 2011, 11:21pm by Boris »

Triholerahduliäöhh gugguh !! (tyrolean joy jodler)
Rough translation: There's a new build of Psi2Win!!
Email: boris[at]psion2[dot]org
starhawk
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Posts: 73
Re: Appears bricked, is there hope?
« Reply #4 on: Apr 29th, 2011, 12:26am »
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Read the instructions  
 
Never mind, I'm not that brave.
starhawk
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Posts: 73
Re: Appears bricked, is there hope?
« Reply #5 on: Dec 16th, 2012, 5:49pm »
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Dunno if there's anyone still here, but I finally got up the nerve to pull it apart. Not that hard, after all! (Actually, I'm kinda sorry it took me so long...)
 
I've found two concerns so far...
 
(1) Looks like some enterprising dork (probably me) put two screws through to the keyboard label from the main board (with CPU and LCD controller). Damage potential: cosmetic only, and I can live with it.
 
(2) This one is a bit more concerning.
 
On the power regulator board, right near the contrast knob, is a chip with some alien goop on half of it. It doesn't /look/ like capacitor gunk, and I see no bulging or leaking capacitors anyways... so heaven only knows where it came from. Near as I can tell, the part is a National Semiconductor version of an LM324 quad operational amplifier (4 op-amps in one chip). I know jack squat about power supply circuitry, so I've no idea what this particular chip does -- but it must be important since I think this may be why the thing doesn't turn on!
 
The gunk, if it's conductive, is shorting out pins 8 through 12 on the chip. Er, for the less-than-technical: pin numbers on DIP and DIP-like chips go in a sort of "U" shape -- so pin 1 is where the little detent (or dot) is, top left of the chip. Bottom left on a 14pin chip (like this) is pin 7. Pin 8 is bottom right, and Pin 14 is top right. Hope that makes sense.
 
This means that (particularly since the 74xx power pin convention is being ignored here) that one op-amp and the input pin for a 2nd, are all being shorted to ground -- again, if the goop is conductive.
 
Here's a pic (at the other end of the link) -- http://img84.imageshack.us/img84/8035/1003047p.jpg
 
(In that pic, the chip with the gunk is RIGHT UNDER the contrast knob.)
 
I could probably clean that crud off... somehow... (ideas, anyone?) but if the chip's cooked, I'm up Whotsit Creek with no paddle -- I can solder okay, but I know my limits -- and SMT parts (like that chip) are well beyond them!
 
I guess I have two questions, then...
 
(1) does anyone know a good way of cleaning gunk off a chip that harms neither chip nor PCB?
 
(2) does anyone living in the US have a dead OrgII with a known good power board and problems elsewhere, that I could have? (I can solder the ribbon cable without problems -- it's the SMT parts that will get me real quick!)
 
Thanks in advance, everyone!
 
EDIT: it appears I have an LZ64 here, by the way. Isn't it wonderful, knowing how to google chip numbers? <g>
« Last Edit: Dec 16th, 2012, 6:16pm by starhawk »
starhawk
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Posts: 73
Re: Appears bricked, is there hope?
« Reply #6 on: Dec 16th, 2012, 8:14pm »
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Figured out what is likely to be the /actual/ problem -- the black (-) wire on the battery terminal is no longer conducting correctly. Looks like, sometime in its history, a battery went kablooey and the results are that the negative terminal does not conduct. I'm going to replace wire as well as joint, as there is corrosion where the black wire joins the PCB.
 
However, this does look to be an easy fix for sure!
 
BTW, the alien goo has been removed from that chip, via toothpick.
starhawk
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Posts: 73
Re: Appears bricked, is there hope?
« Reply #7 on: Dec 17th, 2012, 3:46am »
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IT'S ALIIIIIIIIIIIIIIIIVE!!!
 
I fixed it!
 
No pix of the solder job -- my skills are the sort one does not want to talk about, particularly when faced with the sort of odd angles one has to deal with here.
 
However, I did make a *slight* mod... the battery clip inside had long since lost its spring, so I tossed that (and the little round bit that the spring goes onto) into the dustbin. It now has a more normal snap connector, and (since the battery door is long lost) a small bit of electrical tape to hold the battery in place. I've plenty of electrical tape, so that works pretty well.
 
I'll get some advice (later and elsewhere) on what kind of diode to stick in there for reverse-polarity protection... I assume that as a cost-cutting measure, the design of the original battery connector WAS the reverse-polarity protection.
 
I would LOVE to get a CommsLink cable, such that I could (at least) get the date and time correct... seeing as this little thing's calendar only goes up to 1999 and it's now 2012... but that's not a big deal necessarily.
 
I'll send an email off, shortly, to thesourcerer's most recent address as listed in his thread. I hope he doesn't mind sending stuff to the US, and I *really* hope it's cheap shipping...
starhawk
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Posts: 73
Re: Appears bricked, is there hope?
« Reply #8 on: Dec 17th, 2012, 4:55pm »
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OK, bit of a quandary... my PSION has the two-line display, so it's clearly not an LZ64.
 
In fact, according to the PEEKW calculator, I've an LA model (32k).
 
Here's the problem. The RAM chip claims it's a 64k chip. Datasheet for the series, here (note that the only difference between chips in the series is the access time spec)
 
http://www.vgamuseum.info/images/stories/doc/yamaha/62256.pdf
 
OK, simple math, even I can do this (with a calculator... or a PSION <g> )
 
32768*2 = 65536 (1 word = 2 Bytes = 16 bits)
 
65536/1024 = 64 (1 kiloByte = 1024 Bytes)
 
There you go. 64kB. So... how the heck does that all work out?
Mikesan
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Re: Appears bricked, is there hope?
« Reply #9 on: Dec 17th, 2012, 7:52pm »
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Hmmm, I think you can safely say it's a 32K - only 24K will be available for your programs.  Use OPL to tell you how much is available if you don't believe it
starhawk
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Posts: 73
Re: Appears bricked, is there hope?
« Reply #10 on: Dec 17th, 2012, 9:28pm »
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OK then I'll take your word for it even though I'm still mondo confused.
 
I've sent an email to thesourcerer, but have not heard back. (I used the etherea.oils address.) Does anyone here know how often he checks email, generally? (I'm a total nerd, so for me it's about every half hour at minimum, more if I'm bored out of my gourd )
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