Mac II vs IIx

[wayoutwest]

Here's my dilemma. I have a Macintosh IIx logic board with leaky capacitors. Washed the goo off and got it working, but it failed again after only a week. I also have the original Macintosh II logic board with FDHD upgrade, but the PRAM batteries are dead and soldered to the logic board. No visible sign of capacitor leakage, but that doesn't mean the problem's not there.

I'd like to repair one of the boards, but I'm not sure which is the best to go with. I've soldiered before, but never delicate electronics...so I'm a little leery about trying this.

Anyone have experience with both the original Mac II and IIx? I'm wondering if anyone has seen enough of these machines in their day to have an opinion about the build quality between these two boards. I know the difference in their specs, but I'm wondering (for example) if the IIx was known to have a high capacitor failure rate. That would lead me to just change the batteries in the II and see if I can get away without recapping a board...at least for now.

The II board has been in my possession since it was brand new, so I know its history. The IIx was purchased on eBay within the last 5 years. Supposedly it was a factory service part that was never used. I got it cheap (less than the price of two new PRAM batteries for the II, and there was no need to solder, so it was a no brainer for me at the time). It came in a box with an Apple label identifying it as a service part. I noticed the slots for the SIMM cards do not match (four of the banks are white, the other four are black and slightly different sizes). I suspect this board may have been serviced by Apple and put back into use. But it worked fine when I first bought it.

--Jim

 

[Unknown_K]

I don't have a II but I have a couple IIx systems and a spare IIx motherboard and all needed the aluminum can capacitors replaced. Other then that the big box II's seems reliable (also have a pair of IIfx systems). Build quality is about as good as a 68k mac gets (they were the pro machines of their day).

Those aluminum capacitors have a use life in the thousands of hours and since all those systems are very old they probably all need serviced by now.

Replacing the pram batteries on a II should be easy enough, new ones can be found on ebay cheap (just a little simple soldering needed). If you cannot solder find somebody who can and get them both fixed at the same time. There are not that many capacitors to replace (just do the leaky metal can ones). I think 20 minutes a board is all you need.

 

[porter]

I've soldiered before, but never delicate electronics...

So you weren't in the Corps of Signals or Engineers?

Depends what you want to do with it, with the IIx you could run A/UX. With the II you would need the PMMU.

Desoldering a battery would be easier than doing lot's of capacitors.

My II is actually a II with a IIx motherboard. , and has dual floppies, one 800k the other 1440k.

 

[II2II]

If you don't prefer one machine over the other:

Get the battery holder and battery for the Mac II, and fix up that one. Don't bother trying to solder a new battery on. Not only will a battery holder make the machine more servicable, but the metal contacts used on batteries isn't meant for soldering.

And keep the IIx board in case you want to try the big job one day.

 

[Osgeld]

a battery holder is not a bad idea, batteries are sometimes hard to solder, even if your a self proclaimed expert (like me) and once heat starts to actually soak into the battery there is a slight risk of leakage, or rupture (or violent rupture) due to overheating

any way you decide to go you should get some old junk boards from a pc, alarm clock, vcr, whatever and practice a BUNCH before screwing up a logic board. There is technique and timing involved for electronic devices that you will learn pretty quickly fooling around.

also you need to see if you have the right gear, a 4$ solder sucker and-or some solder wick/braid is neccacary to do it right, I would also suggest tweezers and a pair of needle nose pliers

 

[shred]

Back in the day, both the Mac II and Mac IIx machines were exceptionally reliable - in my experience, anyway. The only common problems were the PRAM batteries going flat (and then the machine wouldn't power on) and floppy drives filling up with dust. Apple later made an add-on clear plastic "dust boot" for the floppy drives to fix that issue.

My employer at the time had a Mac IIx running as a dedicated AppleShare server (with Ethernet and all - a very high end machine in 1989!) that was powered on continuously (except for the occasional power blackout or scheduled downtime for hardware/software upgrades ) for around 8 years without a hardware failure.

 

[wayoutwest]

Thanks for all the advice. I think I'm gong to try replacing the batteries in the II and see if that does the trick. I know the IIx is a slightly better machine, but the II was my primary machine for probably close to 10 years...and while that was a long time ago, it was good enough for me then and it should be good enough today for the very limited amount of use I expect it will see.

Can I just snip the leads off near the battery, and leave them attached to the board so I can reuse them to solder to the battery holders? That way I wouldn't have to touch the logic board with the soldering iron. Do the battery holders need to be attached to something else for support, or will the soldered wire joint be strong enough to handle a careful battery insertion/removal?

 

[porter]

Can I just snip the leads off near the battery, and leave them attached to the board so I can reuse them to solder to the battery holders?

Sounds like a very sensible approach.

 

[Unknown_K]

You can do that I guess, I would just solder in replacement batteries (the leads are fairly long so you will not heat up the battery much unless you are using a blowtorch.

I think my IIx units have a retrofit where there is a board soldered to battery holders that is soldered to the main board (the battery holders leads do not light up otherwise).

 

[Trash80toHP_Mini]

. . . hands down the IIx is a FAR better machine! Back in the day I was shopping for a used Mac II in order to save money. One of the used dealers said I was nuts and that the IIx would end up only a little more expensive than the II once I did the FDD/PMMU upgrade.

I was in the market for a launch pad for the Radius Rocket 33 co-processor card (though the 68030 in the IIx was hardly worth the investment I made in RocketShare) I had my heart set upon and it ran for YEARS! The IIx /Rocket combo wound up getting me thru the entire Quadra Era without my needing to buy one. I finally got a brand new Quadra 630 as a backup to the IIx/Rocket and a home workstation I could use when the rug rat was asleep. It was installed in a custom Desk/Computer Workstation I built to fit between the custom dresser and captain's bed I built for his tiny room in our "junior four" Riverdale (Borough of the Bronx, NYC) Co-op.

To make a long story short, fix the IIx board after a little practice and if you bork it, just chuck it and look for a IIfx board as a replacement!

IMHO, of course!

jt =8-/

 

[Unknown_K]

I would not "practice" on a IIx board, they are kind of rare. The IIx was not out very long before the IIfx came out and many of the II and IIx systems were upgraded to IIfx boards over the years. One of my IIfx units is a II with a factory upgrade.

 

[LCGuy]

Personally, if you've got a IIx, I'd leave it as a IIx if possible - remember, although the IIfx is much faster, if you upgrade it with a IIfx mobo, you'll have a IIfx, complete with 64 pin SIMMs and screwy SCSI - no thanks.