Macintosh IIci

[ironborn65]

I found a Mac IIci, no HD, with a floppy drive, video card, 8MB and PSU for a nice price.
I need to recap it, the electrolytic caps have leaked but apparently it's not that bad.
I'll leave the axial ones.
I did not open the PSU yet, it will need a recap as well

I did not have yet a IIci in my collection ... welcome buddy!

Which network card card I insert here?

 

[ironborn65]

I'm worried here ... gee ...

 

[volvo242gt]

Looks like the 74ALS240 chip marked UH1 should be replaced along with the caps and the 338S6523 chip. Pins are rather corroded, which means the Nubus video card won't work until the chip is replaced.

 

[3lectr1cPPC]

What exactly is the problem with those chips? They don't look too bad to my eye, although the photo of the 338..... chip is a bit blurry.
Edit: UH1 doesn't look very good but it could clean up. You'll just have to see.

 

[olePigeon]

IIcis can be difficult to get going again. So many bad caps next to important ICs. However, looks like relatively little corrosion. I'd recommend removing the old caps, then scrubbing the board down with some white vinegar to neutralize the electrolytic goo causing all the corrosion. Next, clean it with some warm water + soap. Finally, rinse it off with mineral-free water or isopropyl alcohol. Inspect chips for corrosion, repeat cleaning if needed. Leave out to dry next to a fan. Inspect chips and reflow solder if needed. Install new caps.

 

[joshc]

IIcis can be difficult to get going again. So many bad caps next to important ICs. However, looks like relatively little corrosion. I'd recommend removing the old caps, then scrubbing the board down with some white vinegar to neutralize the electrolytic goo causing all the corrosion. Next, clean it with some warm water + soap. Finally, rinse it off with mineral-free water or isopropyl alcohol. Inspect chips for corrosion, repeat cleaning if needed. Leave out to dry next to a fan. Inspect chips and reflow solder if needed. Install new caps.

This.

If there are problems after recap, likely to be in the startup circuit or sound circuit.

 

[volvo242gt]

And, in rare cases, like my old logic board, the Nubus slots being dead, due to UH1 losing ground.

 

[ironborn65]

After a first round of cleaning and the SMD caps removed, I'll investigate the axial one later.
Yeah, there is work to be done here ... quite some , still I do not see damages.
I just hope I don't need to remove the ICs to clean them properly because I see lot of gunk below.

The PSU does not show leakages or bulged caps, still I'll replace them.

 

[ironborn65]

quite an improvement:
+ washing machine, econo mode with lower temperature
+ IPA scrubbing
+ soap scrubbing
+ IPA rinsing
Another round and I'm set

 

[olePigeon]

That cleaned up really well. Nice job.

 

[joshc]

Wow huge improvement nice one

 

[jmacz]

That looks great! Nice!

 

[ironborn65]

tks, guys.
I recapped the PSU but unfortunately it does not work, shortcutting pin 9 and 10 does not starts it up and in any case it does not provide the +5V standby. I will inspect it further for burn-out ares or evident damages, but I don't have competence to make a diagnosis.
I don't like it much, ideally I'd like to fix ... but I'll replace it with an ATX. I did it for a IIsi, adding support for the softstart, this time I'll add a relay for the monitor driven by the +12V.

 

[ironborn65]

What are the options I have for a new PSU?

The ASTEC PSU states:
Output
+5V SB 1mA
+5V 12A
-12V 1.0A
+12V 1.5A
Total power is 90W=60W+12W+18W

Let assume that I'll not use a HD and have one VGA card + NIC card.

I'm thinking of a 150W +12V PSU (typically for LED strips) and a 150W picoATX
picoATX specs:
+5V 6A Max Load 8A Peak Load
+5VSB 1.5A Max Load 2A Peak Load
+3.3V 6A Max Load 8A Peak Load
+12V 8A Max Load 10A Peak Load Max Load 150W
-12V 0.05A Max Load 0.1A Peak Load

The 80W picoATX shows that the Watts decrease is for the +12V only, so this could also work :

Output Voltage (V)	5 VSB	+3.3 V	+5 V	+12 V	-12 V
Output Current (A)	1.5	5.0	6.0	4.0	0.05
Output Power (W)	7.5	16.5	30	48	0.6
Peak Current (A)	2.0	7.0	7.0	7.0	0.1

I'm concerned about the 6A vs 12A difference for the +5V and 00.5A vs 1.0A for the -12V respect the ASTEC

I did this custom PSU for two Mac IIsi, that are ok frankly, even if they were never not much stressed though.
I'm considering this option more carefully now.

Can I go with this configuration? Any thought?

 

[volvo242gt]

It should be similar enough.

For stock Apple power supplies, Astec, Delta Electronics, GE, and Lite-On made models that work in the IIci. At this time, my IIci has my old Centris 650's Astec power supply installed in it. Works fine. The original Astec power supply worked fine, but I figured I might as well have a little extra power.

 

[mdeverhart]

I'm concerned about the 6A vs 12A difference for the +5V and 00.5A vs 1.0A for the -12V respect the ASTEC

I am too. If the -12V were close and that was the only thing that was off, I might chance it. My recollection is that the -12V isn’t used for much (serial ports I think, don’t remember what else). But it’s not close - it’s off by 20x (1A vs 0.05A).

A bigger concern is the 5V rail. That’s used by basically everything, including the main supply for the logic board. 6A only gives you 30W, which I feel like is going to be used up very quickly. I wouldn’t chance it, personally.

I think your overall approach is reasonable, but I’d be looking for a different PicoATX supply that had a much beefier 5V rail (10A+ maybe?), especially if you’re going to have multiple Nubus cards or an accelerator.

 

[joshc]

Check out https://68kmla.org/bb/index.php?threads/stealth-macintosh-iicx-iivx-style-sfx-psu-rebuild.38439/

I used a seasonic 250W when I converted mine.

 

[ironborn65]

got it guys, tks @joshc , I'll go for the Seasonic SS250-SU
I'll later undo the PSU of the Mac IIsi, currently with the +12V PSU + picoATX
I'll try to save the filtering circuit and the relay for the monitor plug driven by the +12V, I think it does not hurt if the Seasonic has it'd owns, is it?

 

[jmacz]

I used this power supply for both my IIci (GE replacement) and Quadra 700 (Astec replacement):

https://www.amazon.com/dp/B00FMJSYA2

It's a Logisys 350W MicroATX unit. The board fit perfectly within the original PS's case. Specs:

• +5V SB 2.0A
• +5V 30A
• -12V 0.8A
• +12V 12A

The -12V is a bit lower than the 1A in the stock PS but there have been folks who did fine even at 0.6A so I didn't worry about it. And both of my rebuilds have been doing fine.

I kept the power ports from the original power supply for both rebuilds but my first one (Astec in the Quadra 700) doesn't have the monitor plug working via soft power (I skipped it -- wish I hadn't). The IIci rebuild however does have a working monitor port via soft power which is great.

 

[mdeverhart]

I used this power supply for both my IIci (GE replacement) and Quadra 700 (Astec replacement)

Looks like a great option, thanks for sharing!