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Elfen

Just crippled an LC III

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Damn, I swear. I was hoping to post up the tale of two recaps of two LC IIIs, but success fails me. One LC III (a LC III @ 25MHz) was dead to begin with. The other LC III (a LC III @ 33MHz) was semi OK, it kept producing random sounds which is attributed to leaky caps. It is the second LC III I crippled.

 

During the recapping, three (1 - 47µf and 2 - 10µf ) caps literally came off the board with no force applied to them and the traces ripped off from the board. It was going so well until I hit these three caps. Then I went to get some wire and found nothing useful so I had to go shopping. I so hate Radio Shack, I got spool of wire and the clerk looked at it as if he never seen wire! Then he said, "This for that Raspberry Pie Robot thing? We don't sell much of those." I just handed him $10 and remained silent. Then I continued on buying other things that I needed - dinner being one of them.

 

Got home, tried to solder tiny bits of wire to the caps and soldered them in place. Put the LC III back together and it bonged! It Bonged with no extra sound! Silence! But then, I got the flashing "?" Disk Icon. I checked my connections and nothing. I'm sure its the cap ( C20 ) by the SCSI connector at the bottom of the board, but now I'm too tired and full of remorse - I crippled my LC III.

 

OK Experts, you think I'm right or wrong? The three caps that came off with traces are: C20, C2 and C18. The area was pretty much surface rotted, but I cleaned it up with a heavy Q-tip and a lot of acetone until it was smooth. All the other caps came of cleanly and soldered in with no problems.

 

As for the first LC, I may have to send it out. This machine was dead since I got it in the late 1990s and it's written all over on the case "NG/NW" for No Good, Not Working. Who ever I sent it too, my SE/30 board will go with it. Even with 3 magnifying glasses I can't find the broken/rotten traces/VIAs on it. Maybe all this surgery crap is playing with my mind and I'm screwing up job that I can do?

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it might sound silly, but are you sure your HDD is ok? I find the quantum's that where supplied with a lot of the LC series have a habit of dieing at the worst times.

 

Also have you checked your PSU voltages? if their out you might find that your hdd doesn't spin up (at least this was the case with my LCII, the psu was out of spec enough to stop the hdd spinning up, but the rest of the system worked fine)

 

Also you should post some pics of your work

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Its still worth at lest testing your PSU voltages, these things always pick the worst time to die. (My LCII was literally working fine one morning, then later in the day it wouldn't keep it's hdd spun up, checked the PSU and the voltages where low, recapped and it all worked again)

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I'll look into it. The 1/2 hour before the recap everything was fine. After the recap, it would not boot up. I think it's that cap by the SCSI port.

 

Anyone knows where I can get an LC/LC II/LC III Schematics?

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Its a 1/2 height Seagate 500Meg'r I had in my 950. The Quantum that was in it died long ago so I put the Seagate in it to do various testing with it for the past year. It boots System 7.5.1.

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I did not test the external SCSI, but it does boot from a floppy.

 

But Good News: I got it working. I removed that cap by the SCSI cable port, cleaned up the broken traces, and built up the trace with more solder before soldering the cap back in. It now boots from the Seagate 500 Meg'r.

 

What got to me is that though it did not boot the first time around, the hard drive sounded like it was going to boot. If the drive is powered up with a SCSI Connection, it spins up and you can hear the heads sweep across twice and then quiets down. But when connected, it would sweep the heads several times like its trying to boot and then dies.

 

In checking the soldered joint when I cleaned it, there is a trace by the cap which also had some solder on it. So I'm thinking that it may have been shorted. That trace, like the cap's trace, goes to the internal SCSI Bus.

 

So, Yeah Me! I got it fixed! It Boots, no extraneous noise from the speaker, and the sound is loud and clear!

Edited by Elfen

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*In baby voice* OOO... LC-3 Went BOOOM! (LOL!)

 

Yes I feel better! A lot better! Now if I had this much luck with the SE/30, I would be doing somersaults!

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