Quadra 650 Battery Bomb Repair

[Elemenoh]

Inspired by @Mac84 's recent stream working on a battery bombed Quadra 650, I decided to try to repair one of mine. This board wasn't too bad, but the battery holder fell off, one of the battery diodes fell off and surrounding areas were rusted. The tops of the RAM pins were rusty too. Not just the ones closest to the battery, but most of them.

I replaced the nearby caps and the LED, then started hunting for broken traces. I removed the bottom two rows of RAM chips, cleaned underneath and scrubbed the rust off of all of the affected chips. The two broken traces near the battery were easy to spot, but the one by U63 was difficult to notice. It was just a tiny little black mark I missed on my first couple of passes. After that last trace was repaired, the machine fired up.

It passes all tests in Snooper. The only issue I've noticed is that the About this Mac window just says "Macintosh" even in System 7.6. I tried 7.5.3 too which should know what this model is. Any ideas why it wouldn't know?

Also, the case itself had some rust spots. I roughly sanded those and then gave it a sloppy spray paint job to the affected area. Hopefully that'll be a good enough fix.

 

[Elemenoh]

Update: TattleTech recognizes it as a Quadra 650, even though the OS does not. ¯\(ツ)/¯

 

[3lectr1c]

7.5.3 still shows the generic messages - think you would need a bit older for the specific models to appear.

 

[Volvo242GT]

You'd need Mac Identifier to get the exact model shown. That said, under 7.6.1, both versions of Mac Identifier seem to crash the system at boot. I think 7.5 is the last version that properly identifies the Mac without neededing the extension or control panel installed.

 

[3lectr1c]

I think 7.5.2 still does it.

 

[Mac84]

Great work @Elemenoh ! You in turn inspired me to take a look at mine again.

My 650 had a nasty battery go off in it too. On a previous stream I repaired the traces, but it was not fixed. So double-checked all the traces near U60 and the RAM chips and they all seemed to be repaired. However, upon inspecting C49, I realized it's ground wasn't connected. I fixed that and borrowed R46 from a working Centris 650 and... ta-dah, it works! System 7.1 does show the machine ID, I believe along the way a version of System 7.5 did stop showing that information.

Snooper 2 passes the board with flying colors. Now I'll have to see if I can salvage the metal on the case.

 

[Elemenoh]

Congrats @Mac84 !

Also, I'm working on a second board. Here's a shot with a lot of stuff in the affected area removed in case it's a helpful reference for others who want a map for continuity testing in that area.

 

[retr01]

System 7.1 does show the machine ID, I believe along the way a version of System 7.5 did stop showing that information.

Correct. The Machine ID was last shown in the About this Macintosh box in System 7.1 before Apple changed that to "Macintosh" in System 7.5 and beyond for the classic Mac OS.

I prefer showing the Machine ID in the About this Macintosh. I wonder if it can be hacked, though. Hmmm. I need good network tools under 7.5 and am unsure how well TCP/IP networking is under 7.1.

 

[3lectr1c]

7.5.3 is when they killed it. 7.5.2 at the very least still had it, not 7.5. And as discussed earlier on mac identifier can bring it back even into OS 8, but it’s a bit buggy. Sometimes it works for me and on other systems it won’t. No idea why.

 

[retr01]

7.5.2 at the very least still had it, not 7.5.

7.5.2 is for Power Macs, not 68k. It is weird that it shows machine ID when System 7.5 and 7.5.1 do not.

 

[3lectr1c]

Do they? Wasn’t aware 7.5.2 was PPC only. I’ve got a spare PowerBook drive out of my 5300 with the original install - give me a few minutes and I’ll throw it in and boot it to confirm.

 

[3lectr1c]

Well rats. It’s got 7.5.3 on it! I remembered wrong. I think my 1400 may actually have a copy of its factory install from a recovery CD on it. Give me a moment

 

[3lectr1c]

Hmm. The plot thickens! My 1400 is actually running 7.5.3! But it does have the identifier. This is an install that was done off my PiSCSI using an image of the original 1400 restore CD.

no Mac identifier installed:

 

[Fizzbinn]

I think the general, supports "all" Macs, installers don't identify specific models. What your noticing is there are special builds that do, at least for:

7.5.2 for PB 190/5300
7.5.3 for PB 1400

I'm not sure if this continued into 7.6 and beyond. I know there are machine specific version of 7.6 for the PB 3400 and I think PM 4400/6500...

 

[3lectr1c]

I’ll try to install the customized copy of 7.6.1 on my 3400 to replace the generic copy of 7.6.1 that’s on there now if the CD is up online. I’ll have look and maybe I’ll do that tomorrow.

what I find interesting is that the 190/5300 got their own restore CDs even though they never supported internal CD-ROM… guess apple expected you’d have an external SCSI CD drive?
Edit: they do! I’ll give it a go at some point. I’ve been trying to get factory install images back on some of my PowerBooks.

 

[Fizzbinn]

I’ll try to install the customized copy of 7.6.1 on my 3400 to replace the generic copy of 7.6.1 that’s on there now if the CD is up online. I’ll have look and maybe I’ll do that tomorrow.

what I find interesting is that the 190/5300 got their own restore CDs even though they never supported internal CD-ROM… guess apple expected you’d have an external SCSI CD drive?
Edit: they do! I’ll give it a go at some point. I’ve been trying to get factory install images back on some of my PowerBooks.

I've got a copy of the PPC upgrade card CD installer for 7.5.2 for the 520/540. I guess having an external CD-ROM was something a good percentage of folks had back in the day (I know I did). Come to think of it I need to look at what that OS shows in About this Mac on my PPC upgraded 540c...

 

[3lectr1c]

Have you archived that disc?

 

[retr01]

Hey, I was wondering if maybe we should have a new thread to discuss more about making machine ID identifiers show up in the About Macintosh. This thread is for @Elemenoh's Quadra 650 Battery Bomb Repair.

 

[Elemenoh]

After fixing the first mildly-bombed Quadra 650 I took a shot at repairing the second much worse board.

This one had rusted RAM sockets and corrosion on all of the SMD RAM and nearby components. Somehow the reset/interupt buttons and nearby components on the other side of the board were also rusted and corroded.

What it took to fix:

• Removed all of the SMD RAM, all RAM sockets, U63, Y2, LED and capacitors in that area.
• Removed rusted interupt/reset buttons, U57, ROM High and nearby cap and resistors
• Replaced LED and buttons. Sockets need to be replaced in the future.
• Used a small rotary tool to scrape corrosion from all legs of about 20 components.
• Scrubbed all pads with solder wick and cleaned board.
• Scraped all corroded traces and vias
• Repaired one broken trace at U61 (how were there not more‽)
• Scrubbed scraped traces with solder wick to protect them.
• Cleaned the board and painted on solder mask.
• Soldered everything back in
• For every RAM chip: scraped the top of all of the legs with a hobby knife to remove remaining crud and reflowed with solder to protect from further rot.

I wasn't tracking my time but it took maybe 8 hours for all of that. It was tedious but also kind of meditative since a lot of the work was very repetitive.

This is the tool I've been using for scraping traces and corroded legs. I've found it to be a lot better than a hobby knife/scalpel. The 1mm bits provide great control in tight spaces without marring other traces or components.

RAM sockets are a pain to remove no matter what, but corroded/rusted parts can be a lot more difficult. Here are some tips to get them out:

• Add fresh solder at all joints. Add extra flux to the crusty ones.
• Desolder with a good desolder gun (I use a Metcal SP-440) without adding extra flux which will cause clogs.
• For stubborn joints, add more fresh solder and then desolder again until mostly clear.
• Starting from one end, apply hot air while very gently prying that end of the socket from the other side of the board. Work your way down the pins, slowly and gently peeling the socket away.

I had zero broken traces doing it like this. The worst socket took about 15 minutes for all of those steps and the others were about 10.

Next steps:

• Sand and paint the rusted enclosure.
• Replace the rusted CD-ROM
• Recap its flaky PSU

After initial cleanup; before repair​

After removal; before second cleanup​

Finished repair​

Running Snooper with no failures​

 

[Elemenoh]

The 120uF cap on the secondary side of the PSU had leaked and was way out of spec. The others tested okay but I replaced those I had in stock, ignoring the bulk caps and the tiny caps on the main PCB as well as a couple on a daughter board.

Here's a reference in case it's helpful to others.

I didn't have a 120uF cap in stock so used a 100uF 25V which seems to be working fine.