Logic Board - Macintosh SE Reloaded

[JDW]

@iPhil64
Very interesting. You get a normal bong, then the Sad Mac. And that icon is shifted to the left instead of being in the center of the CRT.

You also said you get a Mouse Cursor. I assume that means the "Arrow Pointer." You can move it around and see the arrow? I can't see it in your screen shots. I'm curious where the right side upper and lower display EDGES are when you move the arrow pointer around. I am guessing the entire 512 × 342 pixel display area is shifted over to the left, for some reason, which means the arrow pointer should disappear if you move it to the far left and the not go all the way to the right if you move it all the way to the right.

 

[JDW]

Part 2. Okay! I see the PLCC extractor tool, like this one or that one. @JDW, I understand that Hakko sells PLCC extraction tools specific to the number of pins of the PLCC. Is there a larger tool that can extract medium to larger-sized PLCCs?

No way I am paying those prices when something the shape of an ice pick will do the job. I just used an alternative tool I had on hand, which was a spike tipped voltage probe. Even a tiny flat head screw driver might have worked.

Logically, I should have been able to use that PLCC extractor shown in my video (see my earlier post), but I tried multiple times and scratched the chip deeply every single time, so I stopped using that silly tool and used my voltage probe instead. It worked in seconds.

 

[JDW]

Gentlemen, I've had the past week off (Japanese Golden Week), but tomorrow is the start of my new work week. I need to get to bed early this evening. Hopefully, @Kai Robinson can chime in with his thoughts about (1) the cause of the 0000000F 0000000A sad Mac, and (2) the cause of the display shifting to the left.

I have not looked at the schematic this evening to see what might have gotten shorted out with that one SCC chip in backwards, but obviously, that is a concern.

Even so, the fact you are getting a bong is a good sign because it tells us the audio system is working.

 

[retr01]

No way I am paying those prices when something the shape of an ice pick will do the job. I just used an alternative tool I had on hand, which was a spike tipped voltage probe. Even a tiny flat head screw driver might have worked.

Agree! The tip and how much leverage seem to be the key.

I was only wondering if there was a PLCC extractor tool with a larger starting width that may have worked better.

Logically, I should have been able to use that PLCC extractor shown in my video (see my earlier post), but I tried multiple times and scratched the chip deeply every single time, so I stopped using that silly tool and used my voltage probe instead. It worked in seconds.

Yes, I noticed that your probe tip worked well.

 

[iPhil64]

Gentlemen, I've had the past week off (Japanese Golden Week), but tomorrow is the start of my new work week. I need to get to bed early this evening. Hopefully, @Kai Robinson can chime in with his thoughts about (1) the cause of the 0000000F 0000000A sad Mac, and (2) the cause of the display shifting to the left.

I have not looked at the schematic this evening to see what might have gotten shorted out with that one SCC chip in backwards, but obviously, that is a concern.

Even so, the fact you are getting a bong is a good sign because it tells us the audio system is working.

I may test the blue board in between.

Not sure if reverting the SCC has caused damage to other circuits. But yes, that is always a concern.

 

[JDW]

I do hope Kai will chime in to tell us what PLCC extractor he used. But it's usually the case where I am the lone man on the planet who cannot figure out how to use the tool that works for everyone else. Anyway, I bid you all good night!

 

[iPhil64]

I do hope Kai will chime in to tell us what PLCC extractor he used. But it's usually the case where I am the lone man on the planet who cannot figure out how to use the tool that works for everyone else. Anyway, I bid you all good night!

Yep !

Thanks again for your energy and help James !

(maybe I have better news when you wake up ? )

 

[JDW]

Yep !

Thanks again for your energy and help James !

(maybe I have better news when you wake up ? )

I will of course return to this topic tomorrow. After work tomorrow evening, I also have plans to work more on my Color Classic Analog Board video, as well as test a new SSD solution that works in a G4 Cube. Stay tuned!

 

[retr01]

I checked for further insights with the 0000000F 0000000A Sad Mac error code. This is what I learned. That would explain the normal startup bong sound and as the Mac starts up, this comes up?

​

Excerpted from Black & Bleu™/Pro v10.0

Sad Mac Error (0000000F / 0000000A)​

User Explanation​

​

Summary​

An Exception has occurred while starting System file execution. The error most likely indicates a software problem (except as noted below).​

​

Details​

An "Exception" is a Programmer term for a serious (and unexpected) problem happening during the normal activity of the computer. The system has most likely failed because of a software problem but might be a hardware problem. Sad Mac errors occur before the Mac OS is actually fully active. Since the Mac OS isn't fully started at the time the error occurred, there is no way to give you the traditional "Your System Quit" message. Instead, you get a Sad Mac screen.​

​

This particular error is the same as a "Type 10" error. The error could indicate that your System file is corrupted.​

​

What to do​

You should review the explanation of error “10" (using the “Mac OS Errors” option of the Tools menu).​

​

If you suspect that the System file is corrupted, try re-installing it. If that fails to solve the problem, you are probably having a hardware failure. The System file can appear to be corrupted because of bad RAM or a bad disk. These possibilities can only be evaluated with certainty by an Apple Repair shop. Consider having your system examined if you don't feel capable of doing it yourself.​

 

[iPhil64]

I checked for further insights with the 0000000F 0000000A Sad Mac error code. This is what I learned. That would explain the normal startup bong sound and as the Mac starts up, this comes up?

Thanks for checking. In fact the Mac did not have any disk attached to it, so it is very early in the boot process.

I've been far too quick on my tests, I need to be more rigorous now that it is partially alive.

 

[JDW]

the Mac did not have any disk attached to it

Were both internal floppy drive connectors DISCONNECTED at the time you powered on?

Even if there was no disk inserted into a floppy drive, I am curious if the motherboard is attempting to access an attached floppy drive and then crashing with the sad Mac.

If you had any such drive attached, disconnected it and try power on again to see what happens.

Of course, that shifted CRT display is still a concern, and I am unsure what is the root cause of that.

 

[iPhil64]

Were both internal floppy drive connectors DISCONNECTED at the time you powered on?

Even if there was no disk inserted into a floppy drive, I am curious if the motherboard is attempting to access an attached floppy drive and then crashing with the sad Mac.

If you had any such drive attached, disconnected it and try power on again to see what happens.

Of course, that shifted CRT display is still a concern, and I am unsure what is the root cause of that.

I had strictly nothing else connected than the motherboard, RAM and speaker.

So I did some more investigation yesterday.

First of all, I reviewed, removed and reseated all ICs. I paid attention to bent pins. Some ICs really have short pins, like GLU and ADB. This did not cause a change.

Now it doesn't always boot the same way. The sad Mac is the best case.
I also have different boots depending on the RAM I'm using (please note that all this sticks do work without any issue on other boards).

In all cases, the Mac chimes properly.

When I do not get the sad Mac, I either get a more centred but totally unreadable gray screen (like standard texture, but blurred), or a clear black and white checkerboard. Which pointed me to the following change I made.

Using my Larry Pina repair book. I could measure that U2B had some funky measurements on pin 3 and 4, and different from the other boards I have. Remember those Bourns filter were a mixture of new old stock and refurbished parts. So as I had some spare I changed it. No real change in the behaviour, even though the measurements are now in line of what the books says.

I'm thinking of replacing other Bourne filters, though, from the schematics, they appear far from the issue.

I also noted a pretty low resistance between +5V and GND, so I may have some other faulty component.

Or... I did ruin an IC putting it upside down.

 

[JDW]

@iPhil64
Could you post an iPhone video (with audio) of some of your boot attempts?

If no drives are connected, it won't "boot" but it will "power on." So when you make a video, please tell us if there are any SCSI or floppy drives attached. If nothing is attached, then it would simply be a "power on."

 

[Kai Robinson]

Apologies for the late reply - real life has been getting in the way lately - weddings to attend etc - my free time is non-existant at the moment.

For the PLCC extractor - nothing i have worked properly for the 84-pin packages - i resorted to using a dental pick instead, slowly levering each corner bit at a time - that helped.

As for the sad mac - i'll have a think about it and get back to you.

 

[iPhil64]

Guys ! I fixed it totally !

Now starts up great with a crisp picture, perfectly centred. (pictures probably coming soon).

Besides replacing U2B, I removed C67, which as marked as optional, but which I had populated. Also, I did plug the floppy drive, but that was not causing the issue. The Mac now starts with or without the drive.

I would recommend to never populate C67. Which is weird, as it is present on schematics, but on none of the SE boards I have.

Reading schematics and probing components is the way to go.

Now... I lost my microSD in my Floppy EMU, and all my MacSD cards are System 7+, so I don't have a boot drive right now. But state tuned

Thanks to @JDW , @Kai Robinson and @retr01 You do support us so much.


PS: as James kindly suggested between the lines, it technically does not really boot up the OS, it just starts the firmware properly, but that is a good step.

 

[iPhil64]

It now BOOTS on my Floppy EMU as external drive.
Now I'm on something !

What a relief !

 

[iPhil64]

ADB keyboard and mouse are fully functional as well.

So this validates my unconventionally think filters @JDW

I must admit I'm so excited I don't really have test plan....

 

[Kai Robinson]

Aaah yes, thats the H-Sync clamp, i made the same mistake on my initial test board:

 

[iPhil64]

Aaah yes, thats the H-Sync clamp, i made the same mistake on my initial test board:

Yes, that was exactly the effect. I should have watched every of your videos... my bad.

However, it is such a learning experience....

I'm exhausted for today, will do more testing tomorrow.

 

[JDW]

I'm thrilled you solved the problem, and I apologize for not having pointed that out.

I actually have a C67 warning in my Part I video here...

But I edited the text description just now to make that part more clear in the INDEX, and I also added a little Warning emoji next to it as well.

I can imagine how relieved you are, especially having put in an IC wrong. That would have worried me too. But you've fixed it now, and that's what matters!

Congratulations on your successful build! Now it's time for you to have fun testing it further!