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Brett B.

Legit "barn find" Apple IIe

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Small update: I recapped the motherboard and soldered new pins onto a bunch of chips.  I checked out the PSU - looks fine, no damage internally, just some corrosion on the case.  Fired it up and got very few signs of life - a brief flicker on the monitor when I flip the switch and a glowing power light.  I pulled almost all of the chips again and cleaned up the pins - no change.  I get no beep, no video, and the disk drive doesn't spin.  Not sure if it matters but the keyboard is not connected.

 

I found some documentation about what to replace in these situations in order of what symptoms are present but I don't really want to start throwing parts at it and hope that it works.  What would you guys do at this point?  

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 Nothing shorted in the PSU connector area ? a glowing power light is a sign not enough power is coming to the board or too much strain is loading the PSU, what are the voltages under load ?

 


 

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20 hours ago, Brett B. said:

Fired it up and got very few signs of life - a brief flicker on the monitor when I flip the switch and a glowing power light

I recall a similar event happening to me when i picked up my two Apple //e's (Both with 1 Disk ][ Drive, 1 Monitor II, 1 80Col Card, 1 Box of Apple ][ floppy's (came with computer when new), and all of the original manuals (along with Disk][, Monitor II, and (I think) 80Col). There were also two expansion cards, one is a "PRinterface" (Made by Practical Peripherals w/ manual) and the other being a"Printech II" (Made by SMT Systems Manufacturing Technology w/ manual. And lastly a C. Itoh Dot Matrix printer (w/ Manual).

 

Sorry about the tangent, anyway when I flipped the switch the power supply made a high pitch "charging" sound and lit up both lights. The monitor did flash as well like you said.

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16 hours ago, bibilit said:

 Nothing shorted in the PSU connector area ? a glowing power light is a sign not enough power is coming to the board or too much strain is loading the PSU, what are the voltages under load ?

I was under the impression that the power LED should come on and stay on when the machine is powered up?  FWIW I tried connecting the power supply from my ][ - which is known good - and got the same result.  I have not tried connecting the //e's PSU to the ][, but it doesn't seem necessary.  I think it's a safe guess that there's something wrong with the //e motherboard or I'm doing something wrong.

 

10 hours ago, Paralel said:

All traces and vias look ok? It's easy to have a rotted via and not notice it

Man... I don't know, to my untrained eye, the entire board looks OK.  My concern is that I've got an IC socket or several of them that are corroded to the point of not making contact with the chips in them.  That in combination with legs rusted off and soldered back on... I don't know.  Kinda feel like I am just shooting in the dark with so many possibilities.

 

The one solder joint that bothered me was one of the four caps near the power supply connector.  I thought I had accidentally flowed solder over to a pad very close to it but on closer inspection it appears that it's supposed to be that way - it's on the same trace as one of the resistors in that area, or at least it appears to be. 

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Yesterday i was playing with a dead IIe i had at home (not sound, no Power LED), the PSU was dead so managed to hack an ATX PSU to try a boot, but first checked all the capacitors near the connector.

 

One was shorted, so replaced it with a new one (10µf 20v IIRC) switched the PSU, and the capacitor next to the new one bursted litteraly, i replaced this one also and now have a solid power LED (the board has other issues, but is a good start)

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On 1/20/2019 at 11:52 PM, Brett B. said:

I was under the impression that the power LED should come on and stay on when the machine is powered up?  FWIW I tried connecting the power supply from my ][ - which is known good - and got the same result.  I have not tried connecting the //e's PSU to the ][, but it doesn't seem necessary.  I think it's a safe guess that there's something wrong with the //e motherboard or I'm doing something wrong.

 

Man... I don't know, to my untrained eye, the entire board looks OK.  My concern is that I've got an IC socket or several of them that are corroded to the point of not making contact with the chips in them.  That in combination with legs rusted off and soldered back on... I don't know.  Kinda feel like I am just shooting in the dark with so many possibilities.

 

The one solder joint that bothered me was one of the four caps near the power supply connector.  I thought I had accidentally flowed solder over to a pad very close to it but on closer inspection it appears that it's supposed to be that way - it's on the same trace as one of the resistors in that area, or at least it appears to be. 

How is the project going?

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Unfortunately I have made zero progress with it.  I poked around and checked continuity and voltage at several points on the motherboard, and haven't found anything obviously broken but that's about as far as I've come.  I think I am at the point where I need someone who really knows what they're looking at - I'd love to see it come to life.

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