The retro challenge 2010

What a job!

Tue, 20 Jul 2010 20:29:38 +1000

Well it took me an age, I got off to a good start but lots to do at the office cost me some major delays.

The whole idea for this challenge started when the power to my museum mac portable was cut off and my prized mac portable BL would no longer boot. I would just get a sad mac and a sad me :-(

When I opened the Portable, I was shocked to find the board covered in electrolytic and being eaten away, So I decided action was needed immediately and washed off the board.

On removing a number of the bad SMD caps, I found the damage, eaten away tracks, lifted pads, it was a nightmare!

I was horrified, so I tallied up all the surface mount caps I needed, and ordered a mix of equal SMD caps and Tantalum’s. I replaced them all, repainted bad tracks, put in wire runs between destroyed tracks and the end result.... My machine works!

After this little miracle and boost in my confidence, I decided to dust off another Portable Backlit I bought about a decade ago that had an issue where the disk drive always thought it had a disk inserted. This made the machine unusable, so based on this and the fact I had somehow torn the LCD cable (no backlighting) I thought, OK here is a chance to try my magic wand again and see how it goes.

First problem - No backlighting.

I worked out that two of the power
lines in the printed ribbon were cut,
so I traced out the cable on a good
machine and put in some trace wires

I then cleaned it up and kapton
taped the wires in behind the LCD
nicely.

Cleaned it all up and , backlighting working fine.

So second issue.. I had been assuming the SWIM chip was fried about 5 years ago when I was playing with my machine. It was working fine and then all of a sudden died after I was handling it.

So I cleaned off the whole board and started looking around the swim and the caps that surround that part of the board. I saw a dark track under the green coat. I started tracking it and worked out that it should run from one cap to another chip near the SWIM.

The track was dead. I wound out some fine trace wire, bent it out to the correct shape and trail and solder it on, after replacing some more caps I fired her up.. and NO MORE disk problems!

I was so happy I could um, play with three mac portables!

I continued to clean up the third mac portable, which I bought in a box from the states for a princely sum only a few years ago that was giving me a lot of problems from the time I purchased it, and other then not being able to locate a working hard drive its working fine too.

I have to go and dig out the 10 odd portable drives I have and test them all.

I then decided to try and retrofit a really bad Non-backlit I had that was working but being a pain. After replacing one of the caps with a tantalum, it caught on fire and caused some irreversible damage to the board. It does not work at all at the moment.. trying to work it out.

Additionally, I gave up a bit after the fire.. The non backlits are going to be hard.. very hard.

The end of the retro mac challenge

Sat, 2 Aug 2008 13:15:16 +1000

The challenge is over!

I spent today resuscitating fixing my mistakes from the challenge. As previously mentioned I killed 5 Lisa Video boards with a bad power supply that went super nova.

I need to thank Plamen Pasov @ Xyber Data Recovery Centre an old hand at Apple and electronics in general for teaching me how to use and what and oscilloscope is! I am still trying to get my head around it but I learned enough to fix my mistakes!

So we replaced several voltage regulators and voila! VIDEO display on the CRT. Woo!

SO WHAT DID I ACHIEVE AND LEARN

• There is now 7 Completely working Mac Portables in my collection - About 4 of these are completely restored to factory condition.

• I have learned that most of the capacitors on the Mac Portable logic board need to be replaced to make them work properly.

• I have worked out how to restore the sound on Mac Portables that have gone quiet or mute. - Replace the surface mount caps.

• 4 of my 5MB ProFiles are restored and functioning. The 2 10MB Profiles are still dead :( (Anyone that has any idea how to fix these drop me a line!)

• I successfully repaired a Widget SERVO board - Check for damaged trakcs
• I successfully repaired the damaged Video Boards from the Lisa - The 28V Volt regulator - 7824.. Caused no video and everything else works fine.

Next year I will spend more time documenting the challenge. But at least I tried!

I hope everyone enjoyed.

Additionally - I was interviewed for the RetroMacCast this week by James and John. Check it out. Or become a member at retromaccast.com

LISA’s VIDEO BOARDS

Wed, 30 Jul 2008 00:25:37 +1000

Why the picture of a Macintosh manual.. Well simply since I got back from London and Hong Kong I can’t find my chargers for my digital cameras.. they’re in here somewhere!

But back to the issue at hand. In the middle of this retro challenge and complete feeling of nostalgia I decided to help out a colleague of mine with his 3 Lisa’s he’s been sitting on for over a decade. He really only wants 1 working unit which means I may get some spare parts to help me fix my poor 2/5. Well anyway, After being there until 2am I shrugged my shoulders.

The Lisa powers up, and works.. But no internal video display. I subsequently pulled HV’s, CRTS and Video Boards out of all of them and mixed and matched.. No changed. Another series of boards presented no change either. I tested the boards and they were all OK, just no video output.

So anyway after no luck on Monday night. I thought it must be the wiring harness and proceeded to test each wire with a multi-meter.

No dice.

On bring home parts to test in my own Lisa that works, the same issue presented. But alas, presented even with my good parts back in.

I’ve looked at all the SUN repair manuals, been in touch with Vintage Micros (which gave me some useful reassurance) and all things pointed to the fact that my Power supply in its trip in my car had developed a killer instinct.

I have now worked out tonight (non conclusively) that my PSU has damaged up to 5 Video Boards. The only good news is that I have a wiring diagram for the video board and they are a pretty simple circuit other then one chip.

So assuming I have blown only a few or one component on each board, they should be easily resurrected - when I work out what I did.

My mate additionally showed me a oscilloscope last night and we tested the lisa for output of video using it. Its such a foreign idea to me how it works and its going to take a long time to work it out.

The only thing I can say now is, I finally understand why ground in called just that. But alas I still need much more time to learn.

The TAM

Mon, 28 Jul 2008 22:18:28 +1000

This baby arrived in less then 48 hours from the USA. Anyway, this was slightly disappointing - Why you ask? Well it was a 25th Birthday present to myself and much to the disbelief of my colleagues I said when I got in - I will leave it to open it on my birthday. Oh well...

After about 6 hours of very hard work on my behalf getting through things I have been putting off for weeks, I scrapped the idea of waiting little over 2 weeks and thought, blow this, I’m opening her up for QC reasons of course. (The great seller on ebay needs feedback...) yeah.. that’s it.. feedback..

Needless to say it was a nice interlude in the midst of having 2 to 3 lisa’s ripped apart in my living room along with 16 Mac Portables in varying states.

The TAM has been reboxed and awaits a USB/Firewire card from the USA before I decide my weapon of choice for where and how I will present this incredible piece of architecture and computer blended in one.

Servo boards

Thu, 17 Jul 2008 00:28:59 +1000

So I got - Finally - my replacement SERVO board for my dead widget today, and it didn’t work. After looking closely i found a nice big gouge that shouldn’t be there (trust me, there are some that ARE!) Anyway, After my bypass surgery the servo board came back to life. However my 10MB Widget drive did not. Its reporting an Error 82.

Error 82 unfortunately is not good news. It means the drive is not responding. And its definitely the drive as I changed all the controller boards bah the analogue board. :(