You are not logged in.

#51 2015-03-24 04:28:18

iMic
Administrator
From: Adelaide, Australia
Registered: 2014-05-12
Posts: 877
Website

Re: Colour Classic Analog Board Repair

The Analog Board restoration is complete!

IMG_8057sml.jpg


I've replaced 39 capacitors across the board, along with the two burned resistors. Some solder joints on the underside of the board looked rather sad, and I've cleaned those up and braced up a couple of pads that were starting to lift in high heat / flex areas as well. I went over the yoke connector with fresh solder and flux as well.

There's a handful of 2.2uF capacitors, around six in total, that haven't been replaced since that component order was lost in transit. The 330uF 400v mains filter capacitor hasn't been replaced since it was rather difficult to source, expensive and the existing one tested fine.

One of the convergence strips around the CRT neck is still loose. While I've temporarily affixed it to the CRT with duct tape, I'll need to use a hi-temp sealant to permanently re-attach it.


The CRT is bright, sharp and flicker-free in operation, even from a cold startup. The HDD seems to take a couple of attempts to start up still when cold, likely the result of a deteriorated rubber stopper, so I'll need to repair that soon as well.

IMG_8058sml.jpg



Here's an overview of the capacitors that were replaced (green labelled caps were replaced, red labelled caps weren't replaced but passed functional tests). You may wish to open this one in a new tab to see the image at its full resolution.

CC_Analog_Checklist.jpg


Performance wise it's still extremely slow and due for a clean OS install. MJ313 has also graciously provided the LC 550 board pictured on the previous page to this build, so this Colour Classic will soon be powered by a Motorola 68030 running at 33MHz, with a faster system bus and a new memory ceiling of 36MB, raised from the 10MB that the standard Logic Board provides.


Resident Professor of Alternative Methodology
Faculty of Macintosh Restorations & Modifications - "It works, let's fix it!"

Offline

#52 2015-03-24 08:09:13

LCGuy
Administrator
From: Sydney, Australia
Registered: 2014-05-13
Posts: 806

Re: Colour Classic Analog Board Repair

Good job. smile Looks like a great example of a Colour Classic. Also, regarding the RAM ceiling - you may even be able to push it up higher than 36MB, I recall uniserver saying that he has run 64MB SIMMs in LCIII's, from what I understand the LC520 is baically an AIO LCIII...and the Performa 550 is basically a 33 Mhz 520, so it could be possible.

Offline

#53 2015-03-25 17:36:59

uniserver
Member
From: Sf, Mi
Registered: 2014-05-15
Posts: 955
Website

Re: Colour Classic Analog Board Repair

as of right now a 64 meg simm in the LC-III / LC-520 / LC-550 is a bit of a myth,    my memory fades in direct regards to this. pretty sure what i remember
was Trag saying something about this, and a mention of 64 megs does work, but only with certain simms,  pretty sure single sided 64mb?

but then again Trag also said that is possible to hand solder a second simm slot to the LC475/Q605 and that would allow you 256 megs of ram!! haha
-- wish i could find these threads...  :-P

Last edited by uniserver (2015-03-25 17:37:57)


#I Re-Cap √Mac √NeTX √Amiga Boards - A/B - PSU# (MacCaps.com)  Modern SCSI HD's - For Old Macs - Pre Cfg'd - 10k RPM! 73gb!! $50 + free shipping  -- Mac 128K Re-Ram kits (16 Chips) $35 + shipping, Floppy Issues?-> Bourns Filter Solution 128k - SE/30, $16 + shipping

Offline

#54 2015-03-25 17:40:22

uniserver
Member
From: Sf, Mi
Registered: 2014-05-15
Posts: 955
Website

Re: Colour Classic Analog Board Repair

trag

68020

LocationAustin, TX
Posted 03 May 2011 - 05:22 PM
Trash80toHP_Mini said
The real reason for this thread is to expand Apple imposed Q605/LC475 and IIsi memory limitations by building an adapter card that'll use more modern (faster response times) SIMMS on a sub-mobo memory expansion card that'll address all available RAM Banks at maximum capacity.]

That would be interesting. The Q605 definitely does at least up to 260 MB of RAM. I know that from experience. And the 4MB on board can probably be replaced with 64MB, so I imagine that machine could go to 256 + 64 = 320MB at a minimum, perhaps more.

The IIsi should go to 128MB. My understanding is that it's essentially a IIci with a microphone jack, so the memory pins should be there for 128MB.


#I Re-Cap √Mac √NeTX √Amiga Boards - A/B - PSU# (MacCaps.com)  Modern SCSI HD's - For Old Macs - Pre Cfg'd - 10k RPM! 73gb!! $50 + free shipping  -- Mac 128K Re-Ram kits (16 Chips) $35 + shipping, Floppy Issues?-> Bourns Filter Solution 128k - SE/30, $16 + shipping

Offline

#55 2015-03-25 17:44:38

uniserver
Member
From: Sf, Mi
Registered: 2014-05-15
Posts: 955
Website

Re: Colour Classic Analog Board Repair

oh ok here i more info on that

The 260 MB Q605 configuration was accomplished with a 72 pin to two 72 pin SIMM doubler, and no, the lid would not close. But it was a proof of concept, not a configuration intended for operation. The two 72 pin SIMMs were the 128 MB SIMMs we are all familiar with.


#I Re-Cap √Mac √NeTX √Amiga Boards - A/B - PSU# (MacCaps.com)  Modern SCSI HD's - For Old Macs - Pre Cfg'd - 10k RPM! 73gb!! $50 + free shipping  -- Mac 128K Re-Ram kits (16 Chips) $35 + shipping, Floppy Issues?-> Bourns Filter Solution 128k - SE/30, $16 + shipping

Offline

#56 2015-03-25 18:40:30

bbraun
Member
Registered: 2014-05-29
Posts: 1,064
Website

Re: Colour Classic Analog Board Repair

FWIW, the Sonora memory controller used in the LCIII (as configured by the ROM) has 5 banks of 16MB each for a theoretical maximum of 80MB.  The first bank is the soldered onboard memory, leaving a theoretical max of 64MB for the SIMM, although I have no idea what SIMM configuration is required or if everything is wired up to actually support that physically.
For kicks I put a 128MB SIMM in the LCIII, and it doesn't seem to power up.  I guess one could try hacking up the soldered onboard RAM up to 16MB.
The LC520 and LC550 use a Sonora-like memory controller, but it's a different chip.  I haven't dug into the ROMs of these machines to see what, if any, differences matter to the ROM.

Offline

#57 2015-03-25 19:07:02

iMic
Administrator
From: Adelaide, Australia
Registered: 2014-05-12
Posts: 877
Website

Re: Colour Classic Analog Board Repair

The Colour Classic is still showing a few problems. The CRT doesn't seem to be flickering or cutting out anymore, but I'm still seeing some brightness fluctuations - every so often the raster will brighten or dim for a fraction of second before returning to normal. It seems to be occurring the longer the machine has been on, so once it's warmed up.

I'm wondering if a couple of the adjustment pots have been turned up too high to compensate for failing components in the past, particularly the focus and cutoff.

The issue seemed to be resolved, however I was shuffling some of the internal wiring around today... may need to check for a couple of other suspect dry joints in there.


Resident Professor of Alternative Methodology
Faculty of Macintosh Restorations & Modifications - "It works, let's fix it!"

Offline

#58 2015-03-25 22:50:56

MJ313
Member
Registered: 2014-09-23
Posts: 495

Re: Colour Classic Analog Board Repair

bbraun wrote:

For kicks I put a 128MB SIMM in the LCIII, and it doesn't seem to power up.

I tried a 64MB SIMM in mine, and it didn't work either. smile

Offline

#59 2015-03-26 00:18:56

techknight
Member
Registered: 2014-05-22
Posts: 449

Re: Colour Classic Analog Board Repair

you may need to spray out the pots.

Offline

#60 2015-03-26 01:38:49

uniserver
Member
From: Sf, Mi
Registered: 2014-05-15
Posts: 955
Website

Re: Colour Classic Analog Board Repair

is your 64meg simm double sided or single sided?
i think it matters


#I Re-Cap √Mac √NeTX √Amiga Boards - A/B - PSU# (MacCaps.com)  Modern SCSI HD's - For Old Macs - Pre Cfg'd - 10k RPM! 73gb!! $50 + free shipping  -- Mac 128K Re-Ram kits (16 Chips) $35 + shipping, Floppy Issues?-> Bourns Filter Solution 128k - SE/30, $16 + shipping

Offline

#61 2015-03-26 01:39:51

uniserver
Member
From: Sf, Mi
Registered: 2014-05-15
Posts: 955
Website

Re: Colour Classic Analog Board Repair

and yes to the pots...   The Classic and Classic II does that after a re-cap sometimes

clean out the pots and work each one left and right a little


#I Re-Cap √Mac √NeTX √Amiga Boards - A/B - PSU# (MacCaps.com)  Modern SCSI HD's - For Old Macs - Pre Cfg'd - 10k RPM! 73gb!! $50 + free shipping  -- Mac 128K Re-Ram kits (16 Chips) $35 + shipping, Floppy Issues?-> Bourns Filter Solution 128k - SE/30, $16 + shipping

Offline

#62 2015-03-26 09:22:48

iMic
Administrator
From: Adelaide, Australia
Registered: 2014-05-12
Posts: 877
Website

Re: Colour Classic Analog Board Repair

The 2.2uF 200v capacitors showed up today - finally. I went around and replaced all of these as well, six in total, but these ones proved rather difficult to replace. At least once I sucked up the old solder from around a component lead, only to have the entire pad suck up with it! I had to follow the trace down to an open, flat portion of the trace nearby and drill the board, then feed the new capacitor lead through that new hole and solder there instead.

A second solder pad did the same thing, but there were no areas to drill nearby... so I just barely managed to salvage that pad with the trace still attached and solder it down.


After reinstalling the board into the machine... the unstable CRT flickering is back. The top corners of the CRT raster bow outward for a second at random intervals and then snap back. I did notice that this occurred whenever the Analog Board slipped out of the edge connector slightly, so perhaps that connector needs to be cleaned up. Not sure how that would cause the CRT raster to jump though.

The Colour Classic... talk about a massive pain in a small enclosure.

I haven't cleaned the pots yet... I'd actually be curious to know how that's done? Can't say I've had to perform that procedure before.


Resident Professor of Alternative Methodology
Faculty of Macintosh Restorations & Modifications - "It works, let's fix it!"

Offline

#63 2015-03-26 21:37:20

MJ313
Member
Registered: 2014-09-23
Posts: 495

Re: Colour Classic Analog Board Repair

uniserver wrote:

is your 64meg simm double sided or single sided?
i think it matters

Double. It's all I had... stole it from the 6100.

Offline

#64 2015-03-26 22:09:58

uniserver
Member
From: Sf, Mi
Registered: 2014-05-15
Posts: 955
Website

Re: Colour Classic Analog Board Repair

dust gets in them, but mainly just work each one back and forth, (mechanically grinding) in a better electrical connection inside, is the key.
you can clean them with a tooth brush, you can can blast them off with an air compressor.

I don't know where i herd it…but i did hear of someone getting a 64 meg simm to work in the LC-III,  but i think it was single sided…
i have no idea what that even means… maybe its more of the density of ram that it needs,  single sided 64 meg simm is a 128meg simm double sided.


#I Re-Cap √Mac √NeTX √Amiga Boards - A/B - PSU# (MacCaps.com)  Modern SCSI HD's - For Old Macs - Pre Cfg'd - 10k RPM! 73gb!! $50 + free shipping  -- Mac 128K Re-Ram kits (16 Chips) $35 + shipping, Floppy Issues?-> Bourns Filter Solution 128k - SE/30, $16 + shipping

Offline

#65 2015-03-31 03:57:07

iMic
Administrator
From: Adelaide, Australia
Registered: 2014-05-12
Posts: 877
Website

Re: Colour Classic Analog Board Repair

The Macintosh LC 550 board turned up today, much sooner than expected. So, has it made the machine faster?

You'd better believe it.

SimCity 2000 is now playable. The system boots up to a usable state significantly faster. There's no stutter on video redraws when switching colour modes. It's a brilliant upgrade for the Colour Classic with no electrical modifications required. The rear panel fits without any problems.

A massive thank you to MJ313 for supplying this Logic Board. big_smile


The Analog Board still needs some attention. I still need to clean and adjust the pots, and I would like to modify the board to correct one of the lifting traces. The CRT convergence still needs some adjustments as well.

It is coming together though, slowly but surely.


Resident Professor of Alternative Methodology
Faculty of Macintosh Restorations & Modifications - "It works, let's fix it!"

Offline

#66 2015-03-31 14:24:33

MJ313
Member
Registered: 2014-09-23
Posts: 495

Re: Colour Classic Analog Board Repair

Awesome!!

I'm glad it got there... and that it actually works big_smile

Offline

#67 2015-06-07 16:24:17

MacRecapEurope
Member
From: Ireland
Registered: 2015-06-07
Posts: 1
Website

Re: Colour Classic Analog Board Repair

Great Job.

Offline

#68 2015-06-07 18:27:07

cc333
Member
From: North S.F. Bay Area, CA
Registered: 2014-05-23
Posts: 562

Re: Colour Classic Analog Board Repair

And welcome to ThinkClassic, MacRecapEurope (a.k.a. falen)!

c


Main Macs: Early '09 Mac Pro, Mid '12 MacBook Pro 13"
Secondary Macs: Early '08 Mac Pro, Mid '12 MacBook Pro 15"
Playthings: Mac SE/30, 3.0 GHz Mavericks-based HackServe, Many others....
Desired: Lisa, Kanga PowerBook G3, Apple IIc, Apple II, Spare parts, etc.

Offline

#69 2015-06-07 18:49:42

MJ313
Member
Registered: 2014-09-23
Posts: 495

Re: Colour Classic Analog Board Repair

MacRecapEurope wrote:

Bloody Great Job.

FTFY big_smile

Offline

#70 2015-06-26 20:47:29

bbraun
Member
Registered: 2014-05-29
Posts: 1,064
Website

Re: Colour Classic Analog Board Repair

Thanks for doing this iMic.  I've been dreading recapping the analog board for years, and finally got around to it.  Your list and picture helped bunches, and now I have a very nice display!

Offline

#71 2015-06-27 04:31:08

iMic
Administrator
From: Adelaide, Australia
Registered: 2014-05-12
Posts: 877
Website

Re: Colour Classic Analog Board Repair

bbraun wrote:

Thanks for doing this iMic.  I've been dreading recapping the analog board for years, and finally got around to it.  Your list and picture helped bunches, and now I have a very nice display!

Glad the information was of assistance, it's not an overly difficult job, just time-consuming. Also you need to watch out for lifting traces and pads, but that's probably the hardest part.


Unfortunately mine still doesn't work correctly.

I'm at the end of the line with this machine with no idea where to turn, but I did however finally manage to capture a video of the problem in action. (1080p HD.) Watch the corners of the CRT and make note of the brightness / intensity changes.


Resident Professor of Alternative Methodology
Faculty of Macintosh Restorations & Modifications - "It works, let's fix it!"

Offline

#72 2015-06-27 16:48:47

techknight
Member
Registered: 2014-05-22
Posts: 449

Re: Colour Classic Analog Board Repair

Transistor breaking down under load either in the horiz-output circuit, or B+ circuit. A good can of freeze spray or a precision heat source will snuff that one out really quickly. Transistors tend to go noisy before breaking down completely, and rapid temperature swings on transistors defective in this manner, will exacerbate symptoms quickly.

Another thing you can do, is watch the B+ feeding the scan circuits while this is happening, This will pinpoint where to start troubleshooting.

back when I used to service CRT sets when they were still being used commonly, I ran into crap like this all the time.

Last edited by techknight (2015-06-27 16:53:03)

Offline

#73 2015-06-27 17:09:51

bbraun
Member
Registered: 2014-05-29
Posts: 1,064
Website

Re: Colour Classic Analog Board Repair

It turns out mine isn't completely fixed either.  I was using it for an extended period today, and after it had warmed up, I noticed some similar brightness/intensity changes.  It's probably what techknight said, and I should get a can of freeze spray.
I don't have the corner bowing like you've got, although the bottom edge of the screen isn't quite perfect.  I'll focus on the brightness/intensity changes first though.

I also noticed those burned diodes on my board as well.  It seemed like the surrounding area was fine, no damage to the resistors like on yours.  The burned area was limited to immediately around the diodes.

Offline

#74 2015-06-27 22:55:02

techknight
Member
Registered: 2014-05-22
Posts: 449

Re: Colour Classic Analog Board Repair

All the CC boards have those diodes, and they appear to be overheated.

However, I did notice on the LC550+ systems, the AB is VERY similar, but it does not have those diodes.

What function in the circuit they play, I dont know yet.

Offline

#75 2015-06-28 00:13:30

uniserver
Member
From: Sf, Mi
Registered: 2014-05-15
Posts: 955
Website

Re: Colour Classic Analog Board Repair

hey at least it works better then it did!!! 

There is definitely something going on there.

as techknight says, did you change the caps in the CRT board?

also try to make the picture smaller, i think you got it stretched out more then it should be.

could you get a volt meter on the +5 +12 -12, (monitor) just to see when it does that screen anomaly , there isn't any main voltage fluctuation.

if its a transistor that is going bad, i'm thinking it might be one in the CRT Neck board.


#I Re-Cap √Mac √NeTX √Amiga Boards - A/B - PSU# (MacCaps.com)  Modern SCSI HD's - For Old Macs - Pre Cfg'd - 10k RPM! 73gb!! $50 + free shipping  -- Mac 128K Re-Ram kits (16 Chips) $35 + shipping, Floppy Issues?-> Bourns Filter Solution 128k - SE/30, $16 + shipping

Offline

Board footer

About ThinkClassic

ThinkClassic specialises in the maintenance, repair, restoration and modification of Vintage Apple and Macintosh computers. Ask questions and find answers about classic Apple desktops, laptops, accessories and peripherals.