Recapping - Permanent fix to future-proof

[jsarchibald]

I've been away from the hobby for a couple of years (having a baby, building a house, typical adult stuff), and have lost touch with what is happening with recapping and options.

I am wondering what options are available for recapping that will be permanent (ie, never need to replace them again, or worry about leakage).  Is this a pipedream, or is it possible?  I have a number of machines I wish to keep for a long time, and if I am going to the hassle of having them recapped one by one, I want to make sure that it's once and for all.

The machines I want to have looked at will be ones like the Mac TV, Performa 250 (CC), and Quadra 700, but I have a heap of others that will probably need doing as well.

Lastly, if anyone knows someone in Australia who can do these, please let me know.  I have some Portables in for repair, but the guy is doing it as a favour and we are at month 9 already, so he won't be able to help me.

I want to preserve these machines before the caps leak and eat the boards alive, and whilst they work now, I want to save them from needlessly being eaten away.  I am starting to sell of a portion of my collection to fund this venture, so any and all advice would be appreciated.  Would do it myself, but I am afraid I would stuff it up, and time is something I don't really have, so sending it to a pro would be my preference.

 

[omidimo]

Welcome back! 

I am new(ish) to the hobby (Collected for years, but only restoring recently), and I have learned the biggest killers are the battery leaks. I have been fortunate to only have had a few damned Macs form eBay. The first thing to do is to remove the old batteries, if you have had any leaks, that will be the first issue to handle.

CC & MacTV should get full recaps on both motherboard and analog boards. The Q700 is actually a tank, so unless a cap dies, you should be fine. 

If you can find a good re-capper out there in Oz, you should be set. Good luck.

 

[jsarchibald]

Thanks!

I'm always straight onto the batteries, but thanks for the tip!  Just picked up a tidy little stash last night, and all of them still had batteries installed.  Item number 1: remove all batteries!  Just the Classic II with Simasimac to open and check, 50/50 it's caps or leaked Maxell.

Anyone know if there is a thread showing which Macs need recapping, and the relevant boards to recap?  Want to be thorough but don't want to waste time on boards that don't need it.

 

[Juror22]

The closest that I know to a thread for this is this wiki page - https://wiki.68kmla.org/Capacitor_Replacement.

As much as we have been doing this, we should have a list of all the macs with recapping needs (or not) and suggested caps for MB, AB (if applicable) and Power supply.

 

[bibilit]

I have been recapping a lot of units recently.

Except for a few models, all are needing new caps (The early Compacts including the SE, some Macintosh II's and the Q700 don't have SMD mounts and won't need any treatment for the time being)

Some are needing caps all around (Analog and logic Board) those are all the Classics (including the CC, Mac TV)

Some are needing caps also in the PSU units area ( LC's, some SE and SE/30) but also most Powerbooks and Portable

Most Powerbooks are in need of new caps also (1xx series, sometime including screens) but also in some dauther boards (the 100 has a single cap in the processor board and the 190 and 5300 series can suffer from failed capacitors in the charging board, preventing a proper boot.

Some failures are also present in early Imac's....

 

[Elfen]

Welcome back JSArchibald. I have not seen you post in a long while, now I know why... congrats!

The problem is a major issue with larger caps, as finding a solid state version of them is almost impossible to get as they are hard to find if they exist.

Smaller caps on the Logic board are easier to replace and makes a permanent repair that, in theory, can last for the next 20 to 50 years. The choice here is what type of solid state caps you want: with leads or SMT/SMD (Surface Mounted Technology/Devices) and either Ceramic, Mylar or Tantalum. Of the three, they have their pluses and minus, but all function nearly the same and vastly improve the board and its operation. Again, the problem is that these do not exist for larger caps.

I would need to scour the forum's ancient posts, but I read somewhere that somebody took a couple of electrolytic caps and dipped them in an acrylic lacquer, thus sealing them permanently. Whether this works as a permanent solution, I do not know. maybe TechKnight can give a word of advice on this. Personally, I thought the caps have to "breathe" and do swell up slightly during operation to dissipate heat, sealing them traps in the heat.

As mentioned, the Q700 and a few other boards have solid state caps, and do not need to be recapped, except for the larger one. And on the Macs with the built-in monitors, you're stuck with that option of only electrolytic caps for the majority of them. But replacing the caps solves a lot of issues.

 

[Johnnya101]

I was going to mention dipping them too like above said. However, maybe wrapping them in a spongy material might allow them to breathe a bit? Just an idea...

 

[omidimo]

Replacing the fans will also be a dramatic improvement for heat and dust. If you also swap out the old spin drives with a solid state option, that will take the load off the PSU and lower heat.

A nice benefit is the sweet silence.

 

[Unknown_K]

Few hobby machines will have the 24/7/365 use that those machines had when new, and most likely will be in a better climate controlled area. So using the same capacitors will probably not harm the machines down the road.