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Dirty Macintosh IIcx - Restoration and death chime 'fix'


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Posted (edited)

Warning: This thread is photo heavy!

 

I recently picked up a very dirty IIcx from eBay. I wasn't entirely sure what to expect, the photos in the auction weren't great and I wasn't even sure if it contained a leaking battery or not...

 

It arrived earlier this week. The seller didn't pack it well (loose in a box with one layer of bubble wrap), but somehow it survived the UPS treatment undamaged.

 

So, lid removed, and this is what we have. I'm glad the drive carrier/cables are present, those are often missing.

 

E7039FC7-83AC-4C3E-92C4-68CFC0CFF334_1_105_c.thumb.jpeg.0293a180909b78739ff146f7b151f7cc.jpeg

 

So, first things first, check for that PRAM battery...

 

Someone else has done the hard work for me, there is no battery holder!

 

F6DF1159-42BF-448B-96C0-4CBC88322B1C_1_105_c.thumb.jpeg.c03ca6a6f07d567bd707aca63ce378b8.jpeg

 

However, notice that wet area around the caps? Yep, they are leaking badly. But the 'freshness' of this indicates its fairly recent leakage at least.

F9C2CFE5-6025-4DB8-97D7-685358D408DC_1_105_c.thumb.jpeg.f23e3cd3d71e1a4603e8401e02ab5e05.jpeg

Upon further inspection, every cap on the board had done this...

 

159C34F3-2577-48BC-957F-C5FBC6087909_1_105_c.thumb.jpeg.2afbbe7c45eff9d12f76b8a97f709d54.jpeg

 

There's two NuBus video cards, here's what those look like:
 

D91A3F9F-1109-4110-9F4A-144D211292E2_1_105_c.thumb.jpeg.ea42abcb8aac70389dfc88989235a172.jpeg

 

One of them is Apple's Macintosh Display Card (part number 630-0400), I believe that's the 4/8 card?

 

The other is a RasterOps 108+ , maybe somebody had a dual monitor set up going with this back in the day? I think these are both unaccelerated cards.

 

Moving on...

 

I decided to not attempt a power-on test at this stage. There was so much capacitor leakage on the board, and the power supply also looked equally bad, I thought it would be safer and waste less time to just get on with giving it a full restoration.

 

With everything except the logic board and speaker removed, here's the state of play:

 

1BD933EB-D3BF-47C2-8800-FBE4DF70078B_1_105_c.thumb.jpeg.ad9e09f0cef23c48a2390f3a7d18a200.jpeg

 

982DDC45-EE41-40A3-A958-FD95BA5F330D_1_105_c.thumb.jpeg.2b45a550cfc4ee5c1e647e810883a61c.jpeg

 

DF2F01F1-735D-4BC7-B68C-F73B50F79071_1_105_c.thumb.jpeg.8aec465a435fdc328679f542a9ff2154.jpeg

 

DC2472C5-15D5-412D-98A3-2A4F275455CA_1_105_c.thumb.jpeg.7883ef9261b9d82e5622a46a14599021.jpeg

 

And with the logic board out, we reveal ... dust bunnies!
 

BA9EA0BD-A681-4943-971E-1589FD3643BA_1_105_c.thumb.jpeg.c4a6542a8c1ce4d7f7bd2ffe48adbb3f.jpeg

 

The logic board is tired, its seen better days. Let's try to put it out of its misery.

 

4F5A8040-439D-4B8D-BF8C-95F433634DBB_1_105_c.thumb.jpeg.8a9e668cc4407ebed65b0204ba785414.jpeg

 

Let's see what we're really dealing with here...

 

39BC7808-A830-4477-9585-10AEC4EA35FE_1_105_c.thumb.jpeg.4ff6fa9428556ff826b536617d0b4fc1.jpegE8D56647-633C-4BDB-89E8-4CEFD68E9AEF_1_105_c.thumb.jpeg.7ba66375adaa2454003546f59afdd0b5.jpegE13E6349-F54D-4B6B-80C8-ED700C67F839_1_105_c.thumb.jpeg.50785d7765f1335f7b4caf22d3cedbde.jpegC61B8D38-EAB5-4B8F-BC5F-5C3C8065444E_1_105_c.thumb.jpeg.2ce3f48cb08b525a7ba5c49ff576463a.jpeg

 

OK, well that's gross. Time to fix it...

 

First job, an IPA bath:
 

2D4B645B-05ED-47C7-AD59-946F32CE6E67_1_105_c.thumb.jpeg.7f70ce7450fbcc1436b6261ad80bb5c4.jpeg

 

Things got a good scrub too, to really shift all the gunk.

 

F241096C-0C22-4115-9A87-0B4F416AFD44_1_105_c.thumb.jpeg.3e382c63efe25971c2916843fc1dfdc6.jpeg

 

While that was doing its thing, I started to work on the inner case. I don't want to put a nice clean logic board back into a dirty case.

 

There we go, that's better...

 

179BE75E-ACFF-447F-A644-3062017F1859_1_105_c.thumb.jpeg.3ebaf9079745f455adc54c1f8133ad05.jpeg

 

The logic board looked almost brand new after the soak... some solder joints are a bit dull looking but at least the corrosion is all gone now.

 

87B9B028-2F3B-4A6C-9656-CEBC854195B9_1_105_c.thumb.jpeg.b96a5502e2d2e57d0dee9e2a72da73df.jpeg

 

This is now in a workable state, so let's get the next obvious thing done...

 

Time to remove those leaky caps.

 

I did a bit of a scrape around Y4 because there was still some corrosion there, tested continuity and its OK.

 

57B3CA8D-8A8A-4353-8FC0-9343FA7C8D83_1_105_c.thumb.jpeg.4dac37a3ae65434a770a792ddd390a9f.jpeg

 

94CAD68B-FA09-49C4-9A44-DEC189178B82_1_105_c.thumb.jpeg.2f336aa0cce34e8eaf9a1354e0589bc8.jpeg

 

They outstayed their welcome...and now they're gone.

 

C546E4F3-EAE5-4074-A4FA-B62179DD1D47_1_105_c.thumb.jpeg.899307fc1e94189cbdb50a25a9b239ce.jpeg

 

Lots of flux, to make soldering a less painful experience:
 

1EF85B96-320A-4BF8-97AA-15F316DB59C5_1_105_c.thumb.jpeg.59e82fb7d8541fb3c86287e21fb3f92a.jpeg

 

Capacitor leads / old solder removed:
 

25FD7264-DFA5-43C6-82E7-526D1CB10F09_1_105_c.thumb.jpeg.bec70700b58d7efa25f1f1cf2d73fea5.jpeg

 

Cleaned up:

 

1D307704-C0A6-4DCE-8729-E0246962A645_1_105_c.thumb.jpeg.6975f46bd991f79148b5519d7d3796a0.jpeg

 

Same with the other pads:
 

55C597EF-76D5-4DDA-9BC0-2E252745CB07_1_105_c.thumb.jpeg.e041dbac97fa8dff2694b9e30a4e269c.jpeg

 

F556FE80-A4F1-4B04-8AA0-86FE21B66FA6_1_105_c.thumb.jpeg.1f57f248f9a86fcec9a9a58c4ecd55b9.jpeg

 

Now to flux again, so that I can put the new caps on.

 

ED8B0B5A-8CCB-4DB3-A219-FED3337D1CB9_1_105_c.thumb.jpeg.799f06b884f8d66de759a2a3491129e5.jpeg

 

Almost there...

 

3DE26F91-C12F-45D3-A276-8B8CFA39FDEB_1_105_c.thumb.jpeg.a88d328628f678bc2d714bb88d17da1f.jpeg

 

Soldered...

 

C0129F53-B0C8-41AB-A615-807F7AA5F034_1_105_c.thumb.jpeg.e2ce6230c0bb13ca268f551872245d5e.jpeg

 

Cleaned:

 

B2468EC9-EAB2-41A0-A933-4C28A50B2AA2_1_105_c.thumb.jpeg.364e0a6abd3828302f4b598a78a6c3ba.jpeg

 

 

And the others done:
 

21E45DBF-007C-4E32-8EF3-7086105438BC_1_105_c.thumb.jpeg.93a329a6dcce4ca6b806403019f07368.jpegB7977E9B-185A-473B-B67D-D68D5F3B5224_1_105_c.thumb.jpeg.481c517cff6d4d5abb9e7b522837e750.jpeg9BF156CF-F139-4085-9477-BF974EF8692B_1_105_c.thumb.jpeg.6956caa26b5c88ab6f57f17696ee57c9.jpeg

 

 

The next order of business is the power supply... it's in a sorry state. Dirty and smelly. The two things you don't want your power supply to be.

 

5B0C690A-FF3E-4051-9ECE-D2D7831FCD16_1_105_c.thumb.jpeg.013ae3274a461819bf1bf66e4039c2eb.jpeg

 

This was a bit fiddly to get apart. Its two boards sandwiched together, and linked with two sets of soldered cables.

 

65EC1964-F33A-477D-8010-22CA6D3B4D89_1_105_c.thumb.jpeg.fef3d7a9cc9515e2fb1073befbfa8fa4.jpeg

 

 

775B7FC9-CA59-4857-A282-15096733E284_1_105_c.thumb.jpeg.40216346541e1808639f75075c1d505d.jpeg

 

Finally, it's all apart now...

 

AB8B8334-FEF5-4591-812D-591BBA65B9A5_1_105_c.thumb.jpeg.0b6739723173c4fbda0598ba68e5a101.jpeg

 

The Nichicons on the left-hand board were all leaking/bulging. Time to get them out.

 

I use a desoldering station which makes this a much quicker task than doing it with just a soldering iron/wick.

 

Absolutely disgusting... what a mess! I am very glad I didn't attempt to power it on in this state.

 

A0EAFFFA-9F58-488E-8BB6-93D6BA4C53AC_1_105_c.thumb.jpeg.2072115b5a178fe5a6ee76a2a5adfa45.jpeg

 

After cleaning and replacing most (my capacitor supply is running low) of the affected caps:

 

And yes, I did replace the original RIFA filter caps as well. They were starting to crack.

 

631B49FE-6817-463F-93B4-EA6606CD43B2_1_105_c.thumb.jpeg.21abf739e0c85df70642be49062a3de0.jpeg

 

And back together, looking a lot cleaner / less smelly than before:
 

5C0354A9-A955-4DEF-8820-5D7547F91B3E_1_105_c.thumb.jpeg.e4bf284e34087b85eca29231084d2479.jpeg

 

At this point, I felt I'd done enough to give it a try...

 

So, with things hooked up again, I plugged it in, no immediate explosion, good... pressed the keyboard's power button, and I hear a very loud death chime and I get no video output.

 

This didn't immediately concern me, as it confirmed at least a few things:

 

- My repairs to the power supply did not result in disaster/death.

- My recap was probably successful, because sound is clear/loud and most definitely working as it should be.

- The computer's soft power and reset circuitry is working correctly.

- It can get as far as doing some initial startup tests, to the point it can play the death chime which is in ROM.

 

At first, I suspected a RAM problem, as that's usually what causes a sad mac/death chime. I tried moving the bank in Bank B to A, vice versa, and with only A populated and only B populated. None of that changed anything. I also tried a new set of 4 x 1mb SIMMs I bought recently, no change.

 

I tried the Apple video card instead of the RasterOps one, no change. I tried with no NuBus cards at all, no change.

 

At this point I was starting to get a bit stumped. I read somewhere on this forum where somebody had mentioned that a FDD must be connected - well I had started testing with a FloppyEmu plugged into the internal floppy port, so I doubted that theory. I've never had a Mac unable to boot because the floppy drive was disconnected.

 

I tried a spare SE/30 ROM SIMM that I had lying around, no change. Then I realised, there is a jumper at W1 which needs to be removed if the ROM SIMM is populated.

 

And... as Jean Louis Gassée said when this machine was launched... "Well, we have liftoff, I think..."

 

182BFF0A-CA3B-46A2-9396-6E4C056ACEB6_1_105_c.thumb.jpeg.3580987a091416b0aeaa871508fc8740.jpeg

 

So, it now gives a nice loud happy chime, and video. Great.

 

However, it does leave the question "Why doesn't the onboard ROM work?" - that is yet to be investigated.

 

Since then, I've started testing it with a BlueSCSI device which is also working.

 

There are some things remaining to do, which I'll follow up with in a future post.
 

- Figure out why onboard ROM doesn't allow the machine to boot, possibly a broken trace somewhere around there (although on initial inspection it all looks fine)

- Cleaning the outside of the case

- Figuring out a good way of mounting the BlueSCSI device in the machine

- Cleaning the floppy drive

- Finding a suitable accelerator/adapter for the machine (maybe)

 

Hope you enjoyed reading/found this interesting.

Edited by joshc
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21 hours ago, joshc said:

Figure out why onboard ROM doesn't allow the machine to boot, possibly a broken trace somewhere around ther

 

Yes, i had that in mind also, had the problem once with a IIci, but was due to a leaky battery (a trace was broken under the battery holder) but the battery in the IIcx is not at the same place.

 

Can be a bad ROM also (unusual, but who knows...)

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Well done and documented! Are you planning to change the axial caps on MB as well? Could they be related to the ROM issues? Wouldn't you happen to have the capacitor list for the PSU close at hand? The labels on the filter caps have been peeled off in mine.

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Both the IIcx's I've received have had extreme battery damage so you're lucky you got one without a battery!

 

Your pictures just showed me that I have C15 and C16 on backwards!  The rounded edge on the silkscreen made me think positive was to the right.  And you can clearly see the right side going to the ground plane.

 

That may explain my chimes of death and instant startup

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On 3/26/2021 at 4:08 AM, JRotar said:

Your pictures just showed me that I have C15 and C16 on backwards!  The rounded edge on the silkscreen made me think positive was to the right.  And you can clearly see the right side going to the ground plane.

 

That may explain my chimes of death and instant startup


That is well spotted - I have just recapped a rapidly power cycling IIcx with no battery damage and have done the same thing as you. I get instant startup but a happy chime (no idea what it’s actually doing as I have no video card yet). 

Edited by lilwashu
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On 3/26/2021 at 5:54 AM, lilwashu said:


That is well spotted - I have just recapped a rapidly power cycling IIcx with no battery damage and have done the same thing as you. I get instant startup but a happy chime (no idea what it’s actually doing as I have no video card yet). 

Glad I'm not the only one! Let us know if that fixes your problem! 

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On 3/25/2021 at 1:03 AM, ktkm said:

Are you planning to change the axial caps on MB as well? Could they be related to the ROM issues?

Yes, later on, but I doubt they are anything to do with the ROM. (I haven't scanned the IIcx schematics closely enough to confirm if thats true or not).

 

On 3/25/2021 at 1:03 AM, ktkm said:

Wouldn't you happen to have the capacitor list for the PSU close at hand?

 

I'm afraid I don't, I just replaced the ones I had on the go, I didn't make a full list.

 

However I believe it's the same as this one: https://wiki.preterhuman.net/Macintosh_IIci#Capacitor_replacement_.28power_supply_unit.29

 

On 3/25/2021 at 1:03 AM, ktkm said:

The labels on the filter caps have been peeled off in mine.

 

Those are 4700pf 250v film caps. The list above mentions 1 x 3300pf 250v film but I didn't replace that one (might be hidden/covered by a plastic/rubber covering).

 

On 3/26/2021 at 4:08 AM, JRotar said:

Your pictures just showed me that I have C15 and C16 on backwards!

Yup, easily done because for some reason there is no silkscreen for the polarity on those. They are the opposite of all the caps above in that row on the board.

 

I used the recap guide here: https://recapamac.com.au/macintosh-iicx/

 

So... since I blew my own trumpet and declared success on this machine, it turns out there is an issue relating to the 5V trickle required for the soft power to work correctly. On some tries, it is not powering up at all. This was a known problem at the time with these power supplies, as documented here http://www.shobaffum.com/iici/faq.html#11

 

and discussed further here:

 

Testing voltage at D2 on my board and I get a pretty close 4.82V.

 

I've now found that a long keyboard power button press will power the machine on, but sometimes it takes a few seconds.

Bolle kindfully pointed out that the 74HC132 and 74HC74 chips look corroded on my board. I am going to order some replacements of those and try that next.

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19 hours ago, joshc said:

Yup, easily done because for some reason there is no silkscreen for the polarity on those. They are the opposite of all the caps above in that row on the board.

 

I used the recap guide here: https://recapamac.com.au/macintosh-iicx/

 

So... since I blew my own trumpet and declared success on this machine, it turns out there is an issue relating to the 5V trickle required for the soft power to work correctly. On some tries, it is not powering up at all. This was a known problem at the time with these power supplies, as documented here http://www.shobaffum.com/iici/faq.html#11

I usually use that site for power supplies but I guess I need to check it for everything now!  

 

19 hours ago, joshc said:

Bolle kindfully pointed out that the 74HC132 and 74HC74 chips look corroded on my board. I am going to order some replacements of those and try that next.

In the mean time you can try some vinegar on it to see if that helps remove the corrosion.  It was looking pretty puffy.  But that cluster of caps near all that startup logic is a death sentence so replacing them is probably best but won't hurt to try vinegar to prep the board for new chips too

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19 hours ago, JRotar said:

In the mean time you can try some vinegar on it to see if that helps remove the corrosion.

 

I thought that at first, but I've been told, and it makes total sense when you think about it, that the corrosion goes up into the pins and straight into the IC itself... at this point it will just be better to replace them, that way I'm at least totally ruling those out.

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19 hours ago, joshc said:

 

I thought that at first, but I've been told, and it makes total sense when you think about it, that the corrosion goes up into the pins and straight into the IC itself... at this point it will just be better to replace them, that way I'm at least totally ruling those out.

Yeah, true...and cleaning under them would help too

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19 hours ago, JRotar said:

and cleaning under them would help too

 

Yep, I've had success doing this with Egret chips on Classic II boards.

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On 3/27/2021 at 11:53 AM, joshc said:

Yes, later on, but I doubt they are anything to do with the ROM. (I haven't scanned the IIcx schematics closely enough to confirm if thats true or not).

The axial caps are filter caps for the power rails. I guess replacing them can't hurt, but these axials seem quite reliable. On my IIfx, I kept the original ones and it's working fine.

 

also re: RIFA caps

 

Did you also check the filter caps that are enclosed in black heatshrink tube thing? They can be RIFAs too. I have two of these power supplies and both had hidden RIFAs, one even had one that had already blown inside of its heatshrink tube.

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20 hours ago, Arisotura said:

Did you also check the filter caps that are enclosed in black heatshrink tube thing? They can be RIFAs too. I have two of these power supplies and both had hidden RIFAs, one even had one that had already blown inside of its heatshrink tube.

 

Originally, I missed them completely! Thanks for bringing this up.

 

I now have a second IIcx and since looking at some blog posts/various websites, I did come across someone who had removed the heatshrink tubing and replaced those.

 

Here's some shots I took while working on the second power supply:

 

F12F13D0-D2B6-4609-811D-1FBA7777ACF7_1_105_c.thumb.jpeg.78a0d3d8d365e8a870cd118b0853def9.jpeg

 

B35DC905-B9A8-4A90-912D-73584B57CC10_1_105_c.thumb.jpeg.a2d68fa3275933b8ff1bb5f9ccf41271.jpeg

 

As it turned out, one of the RIFAs in my second IIcx had blown already:

 

B39C5EA8-E0DF-4401-AD04-22B2697A8333_1_105_c.thumb.jpeg.52c33f8c024a87eb202f4b2d863ced19.jpeg

 

I will have to order some new filter caps for these now.

 

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