Thread

LC III amusement

68kMLA Troubleshooting 14 posts Apr 7, 2015 to Apr 8, 2015

#1 Tue, 7 Apr 2015 - 23:34 68kMLA

So I can kind of envision some Apple Exec calling the Factory floor and saying.... uh guys, you know those 10,000 boards we were all set to send out? well... yeah... just a bit of a problem with those. They... uh... need to be fixed by Monday. Welp, I'm off to the bar! Thanks for taking care of that! see ya boys!

DSC04291_zpsbwopvacl.jpg.0b02494ccc610cf8cece743aba02c003.jpg

#2 Tue, 7 Apr 2015 - 23:52 68kMLA

So you bought that thing, huh?

#3 Tue, 7 Apr 2015 - 23:54 68kMLA

I got this a little while ago. It was some spares machine LCIII. Nothin' too special

(I wish it was!)

#4 Wed, 8 Apr 2015 - 00:15 68kMLA

i bet it was like a head scratch, what the F kinda moment... i'v seen many LC-III's with that mod.

#5 Wed, 8 Apr 2015 - 00:21 68kMLA

I'm kind of curious what exactly was broken, and who exactly fixed it? Did they have a bunch of dudes just sitting there soldering these little green wires on thousands of these boards?

#6 Wed, 8 Apr 2015 - 00:22 68kMLA

i think it was Singapore, and i think it was a PCB error.

when the LC-III first came out it was a completely different thing.

nothing else was previously like it... however some models soon after the LC-III had similarities

#7 Wed, 8 Apr 2015 - 00:25 68kMLA

I thought it's an overclock mod to 33Mhz? Why move a resistor when you can do it the complicated way?

I think this was before the "move the resistor" easy overclock was known. Of course I could be wrong here... Can anyone confirm? If someone installs 7.1 onto the hdd, if the about dialog box says "Macintosh", then it's overclocked to 33Mhz. If it says "Macintosh LC III" then it's not overclocked.

uniserver said:
i bet it was like a head scratch, what the F kinda moment... i'v seen many LC-III's with that mod.

#8 Wed, 8 Apr 2015 - 01:33 68kMLA

the board in the picture is 25mhz

the mod is an Apple Factory mod.

#9 Wed, 8 Apr 2015 - 01:35 68kMLA

Well I saw one poor bastard on eBay like that, did not know it was as frequent as it was. Looks horrible for a factory mod! Must have been all the interns put to work!!!!

#10 Wed, 8 Apr 2015 - 03:10 68kMLA

Ive seen alot of weird patch wires with PCBs over the years. Gross oversight by the engineers or some sort of schematic/PCB error.

Luckily these days, that dont happen often at all. Considering with most CAD packages, the PCB is linked to the Schematic. As long as your Schematic is OK, you cant really fuck up the PCB unless you overlap traces, but the DRC will alert you.

#11 Wed, 8 Apr 2015 - 13:01 68kMLA

unity said:
Well I saw one poor bastard on eBay like that, did not know it was as frequent as it was. Looks horrible for a factory mod! Must have been all the interns put to work!!!!

haha, yeah, I can picture them breaking out a bunch of 30packs of Natty Ice just to git er done. I had no idea what I was getting with this LCIII... mobo wasn't pictured at all. Fortunately it all works awesome, now.

tk- what's that little chip that is all bound up with wires in the bottom right corner? any idea on that?

#12 Wed, 8 Apr 2015 - 20:04 68kMLA

well that is interesting how the one long wire connects to the EGRET.

Coprocessors
Separate pages are in progress discussing technical features of each of the co-processors used on various Macs. These typically handle ADB, clock, and PRAM, plus power management features on portables and power on/off on some desktops.

68HC05-based Egret (LC, LC II, LC III, Classic II, IIsi, IIvx/IIvi),

341S0850 Egret (v1.01, earlier) PRAM, RTC, ADB; IIsi and LC

LCIII.jpg.510f8e7ab1f4eb6c81645c662a1ebf3c.jpg

u22, pin 11 looks like a ground from the schematic.

Screen Shot 2015-04-08 at 3.03.41 PM.png

so maybe it is a timing/clock issue? as to what that chip is there i guess one way to find out is to desolder it and see what is written on it.

#13 Wed, 8 Apr 2015 - 20:09 68kMLA

ooo hot air station time!

Your board also seems to have a bit of... an alternative way of hooking up the battery.... what happened there??

#14 Wed, 8 Apr 2015 - 20:32 68kMLA

yup just a board to show where the caps are for www.maccaps.com could change the picture but kinda busy lately.