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LaPorta

SE FDHD Restoration

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On 7/7/2019 at 8:14 PM, jimjimx said:

I don’t have a SE around to measure right now, but, Is this your part?

 

https://www.digikey.com/product-detail/en/te-connectivity-amp-connectors/640456-2/A1921-ND/109003

These wound up being the right ones with tolerances of measurements of ~0.05 mm or so (I measured the one I have vs. the data sheet. I'll let you know how they work out when they arrive.

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5 hours ago, LaPorta said:

These wound up being the right ones with tolerances of measurements of ~0.05 mm or so (I measured the one I have vs. the data sheet. I'll let you know how they work out when they arrive.

 Well, let us ALL know how it works out..

Both here, and all over the internet, people talk about finding the right parts for old Macs and all kinds of other stuff, but never tell from who, where, how, and / or what is the modern replacement is.

Like I said, I’ve got a SE SuperDrive with a missing glass cap as well, and nobody replied. That was 2 years ago.

l think there was a server failure sins then, I can’t find the post.

I have to dig it out and look at that board again..

So many things to do.... Right now I’m trying to figure out why my Tannoy i5 MP’s keep going into (what seems like) thermal shut down, and takes more than an hour to reset, even when cool...

They did sound great.

(I’m just frustrated, not really yelling...)

 

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Well, to tell you the truth, I wind up trying to save as much of this information that I find out as part list files, or even writing them down in a notebook I have. No, I'm not "old" (I'm 35), I just have seen, like you, that information can disappear on the internet in the blink of an eye if one is not careful. I certainly will let you know what part and if it works out.

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Small Update:

 

Awaiting my new speaker connector and capacitors from Mouser, they should be here tomorrow. In the meantime, I took to removing the rust from the rear screw-in bar at the back of the logic board. If you look at some of the first pictures from my original conquest post (first photo here), you can see that the bar was literally coated with rust and corrosion. As I have attested to before, the product EvapoRust is incredible. I immersed the bar (after removal) in it for 12 hours, and literally all rust dissolves as can be seen in the first photo. This saves you from doing any manual labor removing the rust. In something this heavily rusted, it also leaves pits in the metal where rust literally ate into the bar, but that is unavoidable. The next step is gently scrubbing the surface with 0000 steel wool (second picture), and then buffing with Black coarse compound with a buffing wheel on a Dremel tool (subsequent pictures). I'm not making it a mirror finish (that's not how it was made), so doing this without sanding works fine. You can see that it looks far better than the originals.

 

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IMG_4477.thumb.JPG.9d65a43c86e9505b557a8b000323cb08.JPG

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Ok, much larger update now. I have made many repairs to the logic board. I repaired all the rotten traces that I could find, either jumping them or soldering across from a terminal to a now exposed area of the trace. I then checked those for continuity. I replaced C4, C5, C10, R1, and R6 because they were either open or out of spec. I also replaced the speaker terminal (thanks to those who helped find that). Lastly, I soldered in a new 1/2AA battery holder.

 

After all of that work, regrettably, I am no closer to the machine working. Upon power-up, the fan spins, disk drive motor runs for a second like any compact, HD spins up, and CRT comes up. I then get the vertical line pattern seen in the final picture. There is no startup sound.  I will continue to check traces and verify continuity, but are there any suggestions as to what may cause something like this?

 

 

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Well, I resoldered a few points, replaced R9 which appeared to be faulty, cleaned and reseated all of the ROMS...and now I get no video at all. Sigh...not sure how I made it worse.

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4 minutes ago, LaPorta said:

Well, I resoldered a few points, replaced R9 which appeared to be faulty, cleaned and reseated all of the ROMS...and now I get no video at all. Sigh...not sure how I made it worse.

That's what happened to me when I resoldered the analog board on my Mac Plus.  I went from getting video when I tapped on the side to no video at all.  I went back and resoldered all the spots I had resoldered before plus any spots that looked in any way imperfect.  It's worked since then.

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I re-verified each and every pin on each socket for continuity...all are good. The next thing on my radar is this "8530 SCC" IC....basically, I don't know what the heck it does, but it is the last thing that I can see that may play a vital role that was near the battery that might not work. I have verified all the traces I repaired vs. the companion logic board I have and they check out. The only thing that I could figure otherwise is maybe an IC itself is shot, and that I don't know how to prove or disprove.

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I have a se fdhd mother board I can send you.  Just pay the postage.  It's a new old stock in a sealed static bag.

661-0536 part number.

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oldappleguy, your offer is most gracious. I do have a donor board if I need it, I was just hoping to have this one work out. I'll try a bit more...if not, it may just become one of my scrap practice boards!

 

I wish I had TechEdison and thoise guys here with suggestions!

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What kind of voltages are you getting around the floppy port? 

 

Did you patch the big trace and its via (shown in red in the picture below)? I can't see it on this side of the board, perhaps you patched it from the solder side?

LaPorta_SE.png.5aeeb1e3ee858d01bd1bc8101598a663.png

 

If it was, then I would check the voltages on each chip (not the filters of course, they aren't needed for now). If all checks out fine, then I'd take the oscilloscope to the CPU to check if the reset line is not stuck or something... The ROM and/or its socket could also be bad.

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I did not patch the red trace because it still had good continuity all the way. If you think I should totally bypass it, I could do that.

 

im going to try all of your other suggestions as well. I can try the ROMs in a good MB I have.

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ROMs/IWM work just fine in another, working SE board that I have without issue. If you can, please explain to me how to check chip voltages: each pin to ground? How do I know what each one should be? Also, more practically...how does one do that with the thing hooked up to the rest of the machine? It's not like I have a long-length AB to LB cable.

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10 hours ago, LaPorta said:

each pin to ground?

That's basically it. 

 

My unit was made in Ireland so it has the longer AB to LB cable. The only solution to effectively create a test bench is to hack up a 24 pin ATX cable. Just make sure you cut it in the right spot as it's keyed.

 

The serial chip shouldn't prevent it from booting. A bad SCSI controller wouldn't allow it to go past the grey screen before the floppy/question mark logo. Something else must be bad on this board but what?? On my board, a few other traces near the ADB controller were bad. I have no idea how acid got there... Might be worth checking elsewhere for damage? 

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I have been meaning to either find or make cables for both the 128k-Plus and the SE series to make a test bench for these machines. What are the voltages supposed to be on these things, is there a list somewhere?

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It's only standardised +-5V and +-12V

Pin Color Function
1 Black  GND
2 Black  GND
3 Black  GND
4 Black  GND
5 Black  GND
6 Blue  -5V DC
7 Green  -12V DC
8 Black  GND
9 White  VIDEO (starts 11.2 usec after falling edge of HSYNC, lasts about 33 usec, first data line is 1.26ms after falling edge of VSYNC)
10 Purple  HSYNC (square wave, falling edge triggered, 45 usec per line)
11 Gray  VSYNC (square wave, falling edge triggered, 60.10 Hz / 16.64 ms per frame, 180 usec low)
12 Orange  +5V DC
13 Orange  +5V DC
14 Yellow  +12V DC

 

source: https://trmm.net/Mac-SE_video

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Thanks, at least this way I can check and see if certain chips are not receiving 5v as they should. I assume that if one has no voltage at all on any terminal, I should start to look there.

 

I appreciate the help, tracking down problems is new to me.

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You can find the pinout of most of the non Apple chips online (the Sony sound chip, the Bob Baily Unit BBU, the VIA, the RTC etc are all specific and pinouts aren't available).

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Ok thank you very much. I also very much need to find a tutorial on using my oscilloscope just so I know what to look for. Any recommendations on a good book?

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