Performa 475 logic board seems ok after 30 years

[CompactManiac]

I took another look at the logic board in my Performa 475 which is now over 30 years old.
I don't see any signs of dulling solder joints or leakage so far.



It could do with a wash though to clear out some surface dust and clean the contact areas. The fan duct also needs cleaned.

I'd like to keep this one as I like how powerful the 475 was for its size and weight but the recap for this will need to wait as others are more urgent.

 

[Phipli]

I took another look at the logic board in my Performa 475 which is now over 30 years old.
I don't see any signs of dulling solder joints or leakage so far.

View attachment 72551

It could do with a wash though to clear out some surface dust and clean the contact areas. The fan duct also needs cleaned.

I'd like to keep this one as I like how powerful the 475 was for its size and weight but the recap for this will need to wait as others are more urgent.

Yeah, I can't fully see in the photo, but what I can see looks pretty good. Is there a little at C137? I can't tell if it is a reflection, or dull solder. I can't see the cap under the RAM stick, but the solder on U22 looks bright. If you wash it in an IPA bath it will clean off any electrolyte that has leaked and help hold off any corrosion, but be warned, running these things sometimes will make the caps suddenly drop their guts.

What I've done in the past when I don't have time is just start by removing the caps and cleaning the board, then come back to it later. Although that was a PM7100 with it's thousand capacitors, a 475 shouldn't take long. The LC and SE/30 are higher priority though, like you say.

Shout if you want a run through on doing these boards, I've done three 475s (others will have done more ). The tricky bit is getting the iron in to solder the new caps next to the hard disk power.

 

[CompactManiac]

I think C137 is ok for now:



The caps under the RAM stick are still shiny - with no dulling on the solder.

The LC floppy drive was a bit wonky a first but it sprang into life reading both PC and Mac disks successfully after it got a clean.
Are those 1.4MB floppy drives getting tough to source at decent prices these days?

 

[Phipli]

Are those 1.4MB floppy drives getting tough to source at decent prices these days?

They were only used in macs so there is a limited supply, but there are so many dead macs around that there is usually one if you want one.

I've not messed with those later manual inject ones so much, but usually it's possible to just fix drives. Only time I've struggled was when I had dead eject motor, and another one that had... Well, someone had left it sat in water. The whole underside was destroyed including the bearings and electronics.

 

[alectrona2988]

i have a manual inject floppy drive i could sell to you for a good price, but i need to make sure it works

 

[halkyardo]

be warned, running these things sometimes will make the caps suddenly drop their guts.

Case in point (different model, but of the same vintage) - my PowerBook 180c. It had sat unused in a drawer in a relative's office since around 1996, if the modification dates on files were to be believed - certainly not the temperature extremes or damp that old computers often find themselves stored in. When I got my hands on it a couple of years ago, I went over it pretty thoroughly before I started using it, and found no signs of electrolyte leakage.

Within about a year of light tinkering type of use, the display began to act up, so I took it apart again - this time, every single electrolytic on the display driver board had a small pool of gunk growing around them. I'm not sure if this was just coincidence, or whether their failure was brought about by coming back into use, but yeah, even 'good' old electrolytics can go bad very rapidly.

One can debate the merits of whether preemptive recapping is necessary, but I think at this point, keeping an eye out for signs of electrolyte leakage is as much a part of responsible vintage hardware preservation as checking your machines periodically for leaking batteries.

 

[djhaloeight]

My Performa 475 is also in very good condition after all these years. Still works perfectly on all original caps, with no signs of leakage as of yet. I do have new tantalum caps for it though, along with caps for my other LC machines that need them. I plan on tackling it once I grab a hot air rework/solder station I've been eyeing on Amazon for awhile.

 

[Juror22]

What I've done in the past when I don't have time is just start by removing the caps and cleaning the board, then come back to it later.

I thought that I was the only one doing this!
...and I take a couple pictures and until I replace the caps, I keep the old ones in a plastic bag, attached to the board with painters tape (usually including a quick status note as well)

I didn't always do it this way, but funny thing - I found its easier to handle them before they go bad and leak all over. Since there seems to be a wide variance in when (not if) the caps leak it just seems prudent. The documentation is a recent development as I work towards better organization.

Its nice to hear there are still ones running well on their original caps - kinda like that rare guy with really good genes that can smoke cigars until he's in his 90's.

 

[CompactManiac]

Its nice to hear there are still ones running well on their original caps

Yeah its fun pushing them to the limit to see how long they will last. At least with the LC pizza box models it only takes 30 seconds to pop off the lid and take a peek inside to see how things are going. I love older electronics and machinery in general - they were nearly always built better especially early video recorders, laserdisc players and hi-fi separates. I'm still using my dad's original Mountfield M3 petrol lawnmower from the late 60's - starts on the second pull every time. You just don't get that level of reliability or longevity with modern equipment.