Mac 128k error 048010

[Megas3300]

Hello all, This is my first post, so bear with me.

I got a Model #: M0001 Mac 128k from my grandparent's basement. When I turn it on, It displays the "Sad Mac" icon and code 048010 there is a patterned dotted line under the code that appears to be changing patterns every half second or so.

I have no clue on the status of the battery, it's there though. I have not opened the unit.

So what's the diagnosis, is there any hope?

 

[JDW]

I would love to see a sharp photo of the screen. I recommend sitting your camera on a tripod and using the camera's timer to avoid blur. Set to the lowest ISO setting to avoid a grainy shot. You may even try setting your shutter speed to manual at 1/60s, and then shooting several times to see if you can avoid the dark raster line coming down the screen. You can see that is how I shot this CRT photo.

 

[Megas3300]

I tried, but my time was limited, I wanted to do better, but my mom wanted her camera back

Well, here...

You can make out 048010 and sort of see the line underneath with the changing pattern, and you can see the pixel line on the one side.

 

[JDW]

Please tell your mother that I offer her my personal heart-felt thanks for the time she lent you her camera and if she would be so kind as to allow you to use it again, she certainly will receive nothing but the highest level of praise for it from all of us here at 68kMLA (or at least, me personally).

I must say your photo is quite unique! It has an ethereal feel to it. I like it (from a graphic arts' perspective). I love the circular glow around the icon.

Now to answer your question...

Your Mac 128k failed a RAM test at cold boot. If you wish to know the technical details, you can view this Sad Mac Code page.

I suspect your Mac 128k has a memory upgrade inside it. Perhaps it was a clip-on upgrade? Pins do oxidize over time and clips come off due to jolts and bumps. You will need to open the case to know more. But such will require a special tool, unless you wish to do as I did when I was 13 (back in 1984) and file down one of my fathers extra-long, flat-head screw drivers so it would fit the torx screw just right. You won't get the job done with a "+" driver though. And even when you get the 4 screws out, you will need to take care to separate the plastic case properly. Don't use a wide flat-head screw driver, as that will chew into the plastics. Often times, shaking the Mac (by holding only the back side of the case, after screws are removed) over a soft bed will do it. But again, be careful. You don't want to shake it too violently or perhaps an upgrade card inside could come lose and bang into something.

All said, you're going to have to open the case. And when you do, I would once again like to get on your mother's good side and have a photo or too taken. I too am quite curious what is inside!

 

[Megas3300]

My mom just had a meeting to go to, she will be back, with the camera. Then I will have all the time I need. I only use it because it's dSLR (I have a main stream digital one)

Anyway, that code chart is quite revealing. I shall attempt to open the back. (I have small electronics torx drivers, not one that size though) It makes a lot of sense.

I am worried about the condition of the screen involving the vertical line and the slight jitters.

Many thanks!

EDIT:

I looked up the chip locations and errors so I can attempt a fix (after I find a long enough screwdriver)

 

[Mac128]

I am worried about the condition of the screen involving the vertical line and the slight jitters.

You should take a read through this: http://68kmla.org/files/classicmac2.pdf before you operate it further to avoid potentially more extensive damage to repair. The good news is, there is almost nothing that cannot be easily and inexpensively repaired once identified.

Rescuing an old Mac is a lot like rescuing a dog if you've never had one. They need lots of care to nurse them back to health and the purchase of a few unique items you are not in the habit of having around your house. Chief among them is to get yourself a good mutli-meter to help keep your aging Mac in good health as its age will continue to show itself, especially under resumed routine use.

Replacing the RAM chips is fairly easy but you will of course need to pick up replacement donors, the easiest means is via another defective logicboard which turn up from time-to-time on eBay. However these are the original 64 chips, not to be confused with later 256 chips associated with the 512K, which are more common. Others may have a source for the chips themselves. I've read enough comments around the net that bad RAM chips are fairly common in these old Macs due to a condition described as bit-rot, so any donor board will have to be checked for bit-rot as well so you don't replace bad with bad. Installing a socket will speed replacement in the future as well, especially if your chips are untestable prior to installing.

 

[Megas3300]

I got it open, using a 10" 1/8" slotted screw driver.

Here are my findings:

I opened it about 5" just to see what's what.

First, I noticed that the CRT is a Samsung....rare.

Second, from what I could see from the side, the chips are unmodified. I was too chicken to go on, it has only been 12 hours since last power test and I was worried that the CRT held too much charge.

I have never soldered before, so likely if the chips are dead, I am going to have to stop there. I have things I can do with the case (itx system anyone?).

No analog board capacitors are damaged, and nothing else looked out of place.

What happens to the internals from here? I don't know.

 

[JDW]

You aren't going to get shocked. Just pull the back of the case completely off. So long as you don't start fondling the red flyback wire and suction cup with your bare fingers, stroking it like a dog, you will be okay. Yes, I've opened these old Macs dozens of times myself, both as a hobbyist and when I worked as a service tech in the late 1980's.

You will not be able to spot many bad capacitors simply by looking at them. But a bad cap is highly unlikely to cause a RAM error, so don't worry about that.

I personally would take time to disconnect and then reconnect all the connectors you see (leave the suction cup of the flyback alone though). Floppy drive connectors, analog board connectors, logic board connector -- reseat them all. If there is a lot of dust on the logic board, then remove the board and blow it off, then put it back and reconnect. Maybe shoot us some photos of the insides while you do this.

 

[Megas3300]

Is there any instruction on that?

Edit: the ram area didn't appear to be modified though.

Is the LV transformer supposed to be this dirty?

 

[Mac128]

Is there any instruction on that?Is the LV transformer supposed to be this dirty?

Tom Lee's excellent repair treatise I mentioned above is one source, or you might pick up a copy of Larry Pina's Mac Upgraded and repair. Also the 128K take-apart manual. Search for apple repair manuals online and you will most likely find one you can download. If not, someone on this board surely has a copy they can send you. However, all of the connections in a 128K simply pull apart. Just be careful not to pull so that you impact the neck of the CRT and break it.

The transformer is often that "dirty". It varies from machine to machine. It is not likely the source of any of your problems.

If you are serious about vintage Mac-ing then you should definitely learn how to solder as you will need to do so at some point. It is extremely easy to do and there are many places on the web which instruct you to proper technique.

Whatever you do, DO NOT ALTER an original 128K Mac. The going rate for a 128K in good shape is over $300, clean working ones up to $1,000 depending on accessories. Sell it on eBay before you gut it. Then if you really want a vintage Mac to gut, pick up a cheap Mac Plus or Classic off eBay or Craigslist, which are available in ample quantity, unlike the increasingly rare stock 128K. If you insist on keeping the 128K and gutting it, rather than restoring it, make sure you do not alter the case or parts permanently. There are several threads on this site that will give you links to many well performed mods. Keep everything you remove from the Mac and store carefully. One day you may realize the value of that 128K, even if you do not now, and the value can only increase unless a huge underground cache of pristine 128Ks is discovered over the next 10 years.

 

[Megas3300]

You've talked me out of it...for now.

I realized the case is physically pristine minus a little yellowing.

I would feel better working on a dead SE or other. Just something I could %100 affirm as dead.

But I cannot find anything wrong visually with the chips.

I have only a Keyboard and mouse, no system disk. (The printer for this thing is still in my grandparent's basement)

My question now...

What is the value of the 128k in its xx( state?

What could the value be if the system is bootable again?

 

[JDW]

I'm not going to attempt to assess the value. I simply wish to thank you for the photos. You have a glorious Mac 128k on your hands. Superb condition! It would be a real shame to sell it off to someone who may not take care of it so excellently as your grandparents obviously did. Even so, if you are contemplating turning it into a PC then by all means sell it.

 

[Megas3300]

I guess I will hold on to it and look for a dead SE or something.

Mabye I will find a dead 128k with donor chips.

 

[Mac128]

I guess I will hold on to it and look for a dead SE or something.Mabye I will find a dead 128k with donor chips.

A dead SE, but don't gut a dead SE/30 as those are much more valuable and can usually be simply repaired. They will generally cost more anyway, so you'll prefer to go cheaper anyway for such a project.

Suffice it to say the value of a non-functional 128K is going to be less than a functional one. However, yours seems to require only a minor chip replacement. A very small soldering job indeed. It is highly unlikely a bad chip will show any visible signs that it has gone bad (unfortunately). Even components that are prone to show damage are hard to spot. Your 128K seems to also be suffering from a voltage problem and is exhibiting signs that it is under stress and one or more components on the analogue board are getting ready to die. However, a simple voltage adjustment may be all that's necessary to restore it to health to take the stress off the parts that are old and weak and near failing. You'll need an inexpensive multi-meter for that and follow Tom Lee's instructions.

Donor boards turn up all the time, so keep your eyes out, learn to do some simple soldering and make the minor repairs that will restore your 128K. The fact that there may be components on your analogue board that are near end-of-life means that you will most likely need to replace a few other components in near future if you restore it to service and make use of it. If you follow Tom's instructions and proactively replace the known problems before they fail you will save yourself much grief and potential additional related part failures. If you don't see yourself working on it at this level, you should probably clean it up as best you can and sell it, listing its known faults. Given the simple nature of these repairs, you will most likely still get a good price from a buyer who is capable of making the repairs and selling it for a profit. It would be a shame to return it to its storage box for another 10 years risking further deterioration and potential damage.

It would be a real shame to sell it off to someone who may not take care of it so excellently as your grandparents obviously did.

I disagree with JDW that someone who might pay $200 or more would fail to take care of the 128K as well as your grandparents or you would. For most Mac collectors, that kind of money inspires some care, especially if they intend to restore it and re-sell it for more.

 

[Charlieman]

You've talked me out of it...for now.
I realized the case is physically pristine minus a little yellowing.

I would feel better working on a dead SE or other. Just something I could %100 affirm as dead.

Good. Recognising that you don't have the soldering skills to perform a repair is a responsible attitude. If you want to learn how to solder, there are loads of good links out there.

Learn to solder by making up a cable. Join two wires together, without overheating the adjacent heat shrink insulator or burning the plastic sheath. Add wires to a big D connector, with lovely tear drops of solder. Then learn how to de-solder. Buy a working 20 year old transistor radio from a second hand shop, and remove a beefy resistor or similar. Solder it back in again and confirm that the radio still works...

But I cannot find anything wrong visually with the chips.

Most electronic failures, even on 25 year old computers, are invisible to the human eye. Occasionally, you can spot a blown resistor under an optical magnifier. But if the observation requires a magnifier, few of us have the skill and equipment to conduct a repair.

 

[tomlee59]

Here are a few simple, non-soldering things to try before setting it aside for another day. From the photo, the board looks relatively clean, but certainly dusty. It might benefit from a thorough and careful clean.

Also, the error message may or may not be correct. The self-test is necessarily somewhat crude, and it can be confounded by other problems. Even though the message indicates a RAM problem, it nonetheless may be worthwhile reseating the ROM chips. Carefully lift them out of their sockets, and then push them gently (but firmly) back into place. Over time, the contacting surfaces oxidize, and a little abrasion restores good contact.

Finally, measure the supply voltages (the floppy connector on the back provides convenient access to all voltages of interest). If they are more than 5% off of nominal, that could be a source of trouble. If they are more than 10% off of nominal, that's almost certainly a problem.

 

[Megas3300]

I have one of these multi-meters, which setting do I use for it to test the voltage?

http://www.universal-radio.com/catalog/meters/1496.html

 

[JDW]

I assume you will be testing on your Mac's logic board, so set your yellow DMM to the DCV section and choose the "20" setting.

 

[Megas3300]

Well, I finally had the time and energy to remove the logic board to get a good look. All the original solder was still shiny and neat. But one thing cought my eye...

The Rom HI chip was slightly ajar from its socket. I take a look and realize I wasn't the first person in here.

Apparently, someone had ATTEMPTED to repair this mac. (My uncle most likely, he was the original owner) I can assure you my friends that I did not cause this damage.

The Rom Hi chip is missing the two pins closest to the 68k processor. I have NO idea how this didn't report a ROM error.

I really can't see how I am going to find another ROM Hi chip.

I can give you this pic, but I couldn't get one good enough to show the missing pins.

I am quite sad now... :'(

I want the remainder of this unit to be as useful as possible. If anyone on this forum needs parts from it, please email or PM me. (andykrew@mac.com)

I wish to give my personal thanks to JDW, Mac128, Charlieman, and tomlee59. You all have provided the best of support.

You all have rekindiled my hobby of retro computer hardware. I wish you the best of luck!