The Mac SE/30 From Hell (Or: How NOT to Solder!)

[d0pefish]

Nice motherboard! Very cool.

They may not be visibly leaking, but if you check back to our A3640 thread where I looked at Steve's card, they can potentially hide all sorts of evil underneath their footprint.

Either way, 20+ years old capacitors could really do with being replaced, leaking or not. I doubt many manufacturers spec'ed long-life capacitors for mass-produced hardware anyway, take Commodore for example, they cut costs wherever possible!

Try turning on the machine without the motherboard attached, if that's possible - if the whining is still there, it could be the PSU or monitor circuits.

 

[Tajmaster]

Cool Ill give it a go

---------- Post added at 21:28 ---------- Previous post was at 21:25 ----------

OK, I switched it on without the motherboard connected and it doesnt make the whining noise.

Also, how long do I have to wait for the capacitors on the CRT to discharge? And do I leave it plugged in or plugged out to discharge?

 

[d0pefish]

Cool

It could still be at least part of the power supply, as it may only exhibit the whining when the circuit in question is under load, as in powering something.

CRTs... oooh, I'd never really want to just guess that one. Best to discharge it. You can do this with a long screwdriver with a well insulated handle, and a piece of wire, preferably with a crocodile clip at each end.

The idea is that you connect one end of the wire to the metal chassis of the case, and one to the metal shaft of the screwdriver. You then slide the screwdriver under the suction cup on the back of the CRT until you touch the high-tension lead underneath - at which point you should hear a CRACK as the tube discharges to earth.

If you're going to attempt this, be sure to read a few guides and watch some videos of it being done to get an idea of what the process is, and what to expect. Also, do it with one hand, and put the other behind your back.

Be very, very careful though!

Oh - and unplugged - definitely unplugged!

 

[tokyoracer]

Taj, funny enough my Macintosh Quadra 630 has the very same issue. I know its a PSU issue since it did it as soon as you plugged it in but before you switch it on. Now i got to find anothrr PSU for it or another machine.

 

[Tajmaster]

Err, I think Im going to just sit it in a corner and let it discharge itself! LOL!

---------- Post added at 21:43 ---------- Previous post was at 21:41 ----------

@Toki

LOL, Im not even a Mac lover! I only have this one as I got it as part of a car boot sale lot a few months ago Im not really sure what to do with it, I also have a 68k CPU based mac laptop but it need a new HDD, thats just sat there too

 

[d0pefish]

@Taj:
The safety rule is to never assume a CRT will ever discharge by itself. You won't be able to tell whether it's holding any charge or not - until it zaps you. You'll definately know about it then... :woot:

Have a look at this old-school official Apple Safety PDF from the service archives - there's a detailed section on the CRT discharging method:
http://preterhuman.net/texts/computing/Apple_Service_PDF/Other_PDF/Safety.pdf

@tokyo:
Service the PSU with new capacitors, it may just cure the whining.

 

[Tajmaster]

Got it saved Dale Ill have a look at discharging it over the weekend cos Ive got to pus it together sometime! lol

 

[iainjh]

hi

you've inspired me to take my se/30 apart tomorrow and have a look at the caps and the battery.

Will in all likelihood ask someone else to change the caps, I've got the shivers thinking about it after reading ..the ..horror.. of what you've just found and fixed.

was tempted to pass it on but seems best I get the caps replaced and keep it in a decent non leaked state whatever I do with it!

ps! awesome work d0pefish!

Iain

 

[d0pefish]

Thanks very much Iain
I'm sure your Mac will love you for renewing its components

Here's the order codes for Farnell that I used if you're interested in buying your own set:

Order Code	Qty		Description				Mftr.		Part No.	
197324		10	 	CAPACITOR, CASE C, 47UF, 16V 		AVX		TAJC476K016R
1672509		1	 	CAPACITOR, 1UF, 50V, CASE B 		AVX		TRJB105K050R
1219475		1		CAPACITOR, RADIAL, 470UF, 35V		PANASONIC	EEUFM1V471
1219468		1		CAPACITOR, RADIAL, 220UF, 25V		PANASONIC	EEUFM1E221

The last two capacitors are radial replacements for the axial capacitors. I decided that since there wasn't a very good range of high-end axials, I'd just use radials - the leads are more than long enough to stretch between the PCB holes.

As you can see, I also used heat-shrink to protect them.

 

[iainjh]

ta for the list. I'll need a battery too wont I?

ps should i use lead/tin solder or the new stuff? have both.

 

[rkauer]

You can use lead, no problem.

It is only non-RoHS.

 

[d0pefish]

I prefer to use lead

I think leaded solder tends to be a bit more malleable and flows a little better.... someone can correct me if I'm wrong

 

[rkauer]

You are right: RoHS solder can look OK and still be a bad joint.

RoHS solder is easy to break by micro-fractures as it is more rigid. And demands a bit more heat to melt.

 

[Merlin]

For components that heat up and cool down a lot, lead-free solder is a really bad idea. See also Playstation 3 and XBox 360....

 

[UberFreak]

Very nice job!

I had to do the same in the past year with 2x A4000 (only one survived), an A1200, A500+ and an A500 (with A500+ board) that did not survive due to just way too much acid damage.
So much work & effort, but seeing them boot is worth it all