Performa 450 new user

[Zare]

If you have no interest in recapping, then old Macs are not for you. Even if the machine is working, the old caps are slowly leaking and eating away at nearby traces and will need to be replaced before it's too late. I buy and repair Mac IIci computers. Even the perfectly working ones immediately get recapped.

Those metal caps in your picture, they are the enemy. You can get recapping kits on eBay for a few bucks.

I don't have SMD gear currently, that's the issue not interest.
Wanted to have a neat small old Mac that can hang around and not use much space and look good and be 'explored' for fun. I was under impression I'm buying a functioning machine.

Did not want a restoration project, it can happen, just not right now.

Almost no PCs from this era used these type of caps. PCs usually used through hole electrolytic caps, if any at all during this time, but mostly had tantalum caps.
These Macs used surface mount electrolytic caps, and early ones especially have faulty seals that fail prematurely, causing the electrolyte to leak out. This also happens on some through hole caps, but it’s less common. These caps first started failing commonly in the early 2000s, and then newer and newer ones started leaking as the years go on. It’s the general rule now that if it’s pre-1995, it needs to be replaced.
It’s not mainly a function of use, although that may exacerbate it, just one of time. The seals will fail regardless of storage conditions, hours, whatever.

Yeah I know what's the difference between them but did not know about the casing problem. Thanks for explanation
However PSU is definitely working. 12 and 5V stable, disk spins up.

Both.

Not good.
I'll check into the restoration guide posted by @utuberangerbob and dissasemble the entire case.

 

[utuberangerbob]

Ok guys please explain to me what's the deal with these capacitors before I decide what to do here.
On none of my 30+ year old PCs I had to do this. What makes these so bad and what makes your opinion so rock solid without even knowing the number of power-on hours of the particular board or PSU?

Some capacitors, like Polaroid pictures, just don't last as long as the designers intended. The metal capacitors used on these older Macs have a paper material holding back the electrolyte from under the metal can. I don't know if the paper shrinks over time or if it's the metal expanding and contracting with use, but eventually they are going to leak. The PC and even other Apple computers didn't use these particular capacitors on their boards, so they don't have the same issue. Now, while Apple ][ computer motherboards don't contain such capacitors, they have one or two RIFA capacitors in their power supply module. These will eventually explode and catch fire, but the motherboards will remain trouble-free for many more decades. Apple ][ Forever!!

 

[3lectr1c]

I don't have SMD gear currently, that's the issue not interest.

All you need is a soldering iron, it’s not nearly as difficult as you’d think. I’d recommend watching the how-tos made by Branchus Creations on YouTube.

 

[3lectr1c]

@utuberangerbob - I think it’s just the rubber seal on the bottom going bad.

 

[utuberangerbob]

SMD equipment not really required to replace these caps, just a steady hand and a fine-tipped soldering iron. See https://www.youtube.com/@adriansdigitalbasement videos on how to recap old Macs. I'll look for a relevant video and edit into this post when I find it...


Like so, but I don't do the heat-n-twist that he does. Your mileage may vary.

 

[utuberangerbob]

@utuberangerbob - I think it’s just the rubber seal on the bottom going bad.

Yeah, that's right, but I think I've seen a cardboard material on some. But rubber drying out and shrinking/cracking over time is definitely the more common thing.

 

[3lectr1c]

Like so, but I don't do the heat-n-twist that he does. Your mileage may vary.

The twist method is probably best if you don’t have soldering tweezers. Using just an iron is too risky and using a hot air station causes the caps to pop and let off a ton of fumes, though it does work.
I twist them off myself - it will break the pads if you do it wrong, but it shouldn’t if you do it right.

 

[utuberangerbob]

Are old Mac ADB keyboards and mice common and cheap in the EU as they are here? If not, I'd being willing to send you a set for the cost of shipping. I have dozens.

Apple Design Keyboard And Mouse LOT 2 KYB 5 MICE | eBay

This Apple Design Keyboard and Mouse bundle includes everything you need for a seamless computing experience. The sleek and stylish beige keyboard features a standard QWERTY layout, perfect for any user. The wired connectivity via ADB ensures a reliable connection and easy setup. The lot...

www.ebay.com

 

[Zare]

Ok guys, I think I should give it a try. It seems to be in great condition and it was cheap enough for me to decide not to return it - 50eur with shipping. I will contact the seller and explain them they made an error in judgment. I do not believe I can get a restored machine in near mint condition at this price.

Going to start with caps in the PSU first, those might even be available in my local store. After I do some practice with SMDs on broken cards I'll attempt to recap the logic board.

What are the chances something else is broken?

@utuberangerbob thank you very much for kind offer. The items aren't expensive here but not that common. Lets see about fixing the machine first.

 

[3lectr1c]

For PSU caps make sure the ones in the output side are low ESR.

 

[GiGaBiTe]

Like I said in 1st post, I do not have a monitor or a keyboard...
Also nothing anywhere appears to be damaged.

Those caps in the sound circuitry are definitely leaking. If you look at the board, you can see what looks like wet hairs. The electrolyte is almost clear with a slight yellow hue, but it will capture dust and stick.

You need to get that electrolyte off the board, don't let it sit. If you can get a can of CRC Lectra Clean, hose the board off with it. Just make sure you have the logic board removed, Lectra Clean will etch and melt plastic. I don't recommend IPA, because it oxidizes the electrolyte and just makes a huge mess that's hard to clean.

Another option if you can't get Lectra Clean is to put the board in the sink and wash it with hot water and dish soap. Use a soft paint brush to scrub around all of the chips. Blow dry it with an air compressor, making sure to get under the chips and in the sockets.

 

[GiGaBiTe]

However PSU is definitely working. 12 and 5V stable, disk spins up.

If you don't have an oscilloscope, you can't make that call. Bad power supplies can put out what looks like normal voltages to a DMM, but what you don't see is the ripple current. Bad capacitors usually cause extremely high ripple in the outputs, which can't be seen by a regular DMM.