Squares on the screen at boot time.

[juanjavier]

This appears on the screen when I turn on the Classic.

This has been happening these last days, but always get solved by leaving the mac unplugged from the mains for a while (often even an hour). Then the Classic used to boot ok.

But last night I left the Classic unplugged and this morning still keeps doing it.

What should I do?

Thanks for a quick reply. Regards.

 

[coius]

That, my friend, would the the capacitors leaking on the board. The only option you have is to replace the caps on the board. either that, as a short-term is to wash the gunk from the old caps off the board, would be to put the board in a dishwasher.

 

[juanjavier]

That, my friend, would the the capacitors leaking on the board. The only option you have is to replace the caps on the board. either that, as a short-term is to wash the gunk from the old caps off the board, would be to put the board in a dishwasher.

---If the capacitors leak on the motherboard, which seems a very harmful hardware failure...would it be possible that I had taken this screenshot twenty minutes ago? [] ]'>

What I mean by that, is **not** the Classic is dead showing squares on boot time forever, but only sometimes...mostly when I turn it off and reboot...so chances are this or this, taken directly from the Apple website

---Only just to confirm. So I will be in search of a Thorx D-15 screwer next monday in order to a) replace the 3,6 V battery from the motherboard, which AFAIK could be **almost dead** and possibly causing the boot squares on screen, as well as verify the ROM/RAM chips are firmly tight on to the board..

Will keep posting on this. Thanks for the reply... :beige: :beige:

 

[porter]

So I will be in search of a Thorx D-15 screwer next

You definitely need to get inside. Basically it powers up but the CPU isn't doing it's initialisation.

Any sounds?

 

[Dennis Nedry]

I've never seen a really long torx screwdriver at a store that will reach all the way down inside the handle of a compact Mac. Only pictures of them.

It's sometimes easier to find the right size bit, then put some extensions on it to reach all the way down in the handle. That's what I do. The bit itself should probably be the 3-inch long kind (or longer is obviously OK), then you can just take an ordinary 1/4" socket to it.

 

[juanjavier]

So I will be in search of a Thorx D-15 screwer next

You definitely need to get inside. Basically it powers up but the CPU isn't doing it's initialisation.

Any sounds?

---No «bong». According to the repairing mac link I posted before, it seems to be (copy-paste):

Diagnosis(1) The most probable cause is connection troubles between the ROM-SIMM and the ROM-SIMM slot.(...)

---As for the Torx screw-driver, no problem. I found out I have got the perfect one. Reaches the handler screws in the upper back of the case pefectly.

Today the Classic booted up again succesfully and I worked again fine with it. But chances are tomorrow it won't. So perhaps 3,6 V battery may be dead (could I boot without battery...?) Let's see where all this takes me....RAM?...battery? :-/

I will keep posting...

 

[Dennis Nedry]

The problem is not the battery if you hear no startup sound. It is likely a bad connection with the ROM or something else.

I could be mistaken but the screwdriver in the picture looks like a phillips (cross shape), and the screws in the Mac are Torx, which is a 6-point star shape. "T-15" to be exact, but you might be able to get away with T-10 (not recommended, it could strip).

 

[juanjavier]

The problem is not the battery if you hear no startup sound. It is likely a bad connection with the ROM or something else.

Check solution 3 here

Anyway I shouldn't theorize. Just will open the Classic and see what can be done....

I could be mistaken but the screwdriver in the picture looks like a phillips (cross shape), and the screws in the Mac are Torx, which is a 6-point star shape. "T-15" to be exact, but you might be able to get away with T-10 (not recommended, it could strip).

--Perfect, Dennis. Will check that tomorrow Monday and will keep posting.

Thanks for the reply! [] ]'> [] ]'>

 

[juanjavier]

Found the right torx t-15 screwdriver, €2,10.

This is what I found:

ROM and every other chip ok. No leaking capacitors in the motherboard.

Battery out, installed a new one. This is not relevant, since Classics can run with no battery.

Tried unplugging hard SCSI drive and floppy drive out from the motherboard and then booting.

Still the same.

Hmmmm, let me think.... :-/ :-/ :-/

BTW, if I unplug the RAM expansion card...should any jumper in the motherboard be changed? Which one?

Regards...

 

[Dennis Nedry]

Try just removing the RAM and putting it back in, also with other parts that can be removed. This may improve a dirty contact.

 

[juanjavier]

That, my friend, would the the capacitors leaking on the board. The only option you have is to replace the caps on the board. either that, as a short-term is to wash the gunk from the old caps off the board, would be to put the board in a dishwasher.

---Uuups...by that do you mean this and this? Or this has got just nothing to do?

Anyway the Classic starts up ok within a few power-on retries. This last picture was taken after the other inside pics, once reassembled....

Thanks for a quick reply....

 

[Apostrophe]

Yup, those are leaking capacitors and you'll want to replace those as soon as you can.

I've never done it myself, but from what I hear it's easy and it highly likely to permanently fix the problem.

-Apostrophe

 

[juanjavier]

Yup, those are leaking capacitors and you'll want to replace those as soon as you can.
I've never done it myself, but from what I hear it's easy and it highly likely to permanently fix the problem.

-Apostrophe

------Great. Is good to track a problem. :beige: But:

The trouble is that I myself **do not** have soldering skills...do not know who could help me.... :-/ ...even if those capacitors will be able to find....

 

[Dennis Nedry]

I don't doubt you have leaking caps, but I don't see anything in the pictures... The globby white stuff is normal hot glue on the analog board I believe? From what I've seen caps leak a clear liquid that's difficult to even see sometimes. I think the capacitors that are leaking are probably on the logic board and not the analog board.

Soldering this kind of thing is not difficult. Find some old broken electronic stuff with big capacitors (i.e. an old TV or VCR, etc.) and use a soldering iron to remove some components. You'll get the hang of it. Then you can try putting them back in and repeating the process with smaller components. Be careful not to burn yourself on the little guys, they get hot quite quickly even on the opposite side of the board.

You will need an iron, some solder, and maybe one of those solder vacuum things. You push the shaft down to load it up, then press the button to fire, and it sucks up hot solder. These things can all be gotten at RadioShack.

 

[juanjavier]

...the globby white stuff is normal hot glue on the analog board I believe? From what I've seen caps leak a clear liquid that's difficult to even see sometimes. I think the capacitors that are leaking are probably on the logic board and not the analog board.

----Uuups, my fault again, sorry :I :I :I :I

As you see, I am not proficient with inside-Classic stuff....

Some other people told me just the same....these white leaking thing is **not** leaking from capacitors, but glue to prevent them moving on the board...

I did not see any capacitors in the Macintosh Classic logic board, but chips only, as well as a 50 pin SCSI conector, floppy connector, 44 pin memory expansion card connector, ROM, RAM chips and no more.

Where are the logic board capacitors? Is the logic board that green one on the bottom of the Mac? There is no capacitors there, as far as I recall.

As for the white glue from the capacitors on the analog board, I have *not* seen any other capacitor with *any other* kind of leaking.

So, if that from my picture is *not* capacitor leaking, then *NO* capacitor is leaking in any of the boards: logic--> there is no capacitor there; analog---> white glue is the only thing I see..... So now, what?

 

[Dennis Nedry]

The logic board is the board on the bottom of the Mac. It has some very small capacitors on it. They don't look exactly like the big ones. They are very small little cylinders. The connections are made on the surface of the board and don't go all the way through to the other side.

 

[beachycove]

Remove ram, take logic board, and wash it well, soaking it for a good, long time, followed by rinsing. Possibly even scrubbing lightly with a clean toothbrush where the goo from leaking capacitors may be bridging chip connections might help. I have also occasionally rubbed very carefully with ethyl alcohol, which seems to remove the most persistent goo from between chip connectors.

Let it dry for several days, or a day in a soft breeze if you are in a warm climate, reinstall the board, turn the machine on, and see if this improves matters. Soldering may not be required (for now).

The capacitors on the logic board are mostly those little silver/ aluminum coloured "tanks". There are maybe 12-15 of them, and they come in a number of sizes. They have lettering on them such as "20µF 5v" and other such specifications.

The washing/ scrubbing approach described just revived a CII that was given to me as scrap, which is nice, as I have wanted one for years.

 

[tomlee59]

Yes, apostrophe's led you a bit astray. The stuff in your photos is just hot glue, used to secure the components in place.

The residue from electrolytic capacitors is not that voluminous. It's mainly visible as a dirty smudge on the circuit board, immediately surrounding the capacitor, but not generally obvious on the capacitor itself (except, perhaps, on its underside).

Your problem is almost certainly from leaking capacitors on the logic board. Yes, by all means check ram and rom (because it's easy to do so), but you will almost certainly find those to be fine.

The only true fix is to clean the board, and then replace the electrolytics in question. It's not hard (just time-consuming). And if you use good caps (tantalums), the repair will last a good long time.