Restoring SE/30 - Melted/damaged CRT power and CRT residue

[estravolta]

Hi all! I am working on restoring my first classic Mac, an SE/30. I've started to dive in and have ordered capacitors and such, cleaned it, taken out the PRAM battery, et cetera. I powered it up after giving it a good cleaning and got a relatively dim vertical line. Page 162 of Dead Mac Scrolls indicates a potentially bad resistor (R19). (Screenshot from the book below)

There are two primary things I'm concerned about, and would love some guidance.

First, there's some residue around the anode cup -- is this anything I should be worried about?

And mainly, one of the power connectors that goes from the CRT to the analog board is very damaged. When I received t, it looked like someone had soldered one of the wires to the back of the analog board. When I took everything apart, the connector is much more damaged than I realized. How bad is this? Is it fixable? If so, any guidance on best practices and parts?

Thanks in advance!

 

[davidg5678]

The goop around the anode cap is a combination of dielectric grease and probably also some deteriorating rubber. You can get rid of the stickiness using a paper towel soaked in isopropyl alcohol. Just make sure not to drip anything inside the crt hole. I believe you can get replacement dielectric grease at an auto parts store (although I've never added any after removing the old stuff and my Mac works fine)

The charring around the connector is more of a severe issue. You should replace both the male and female connectors. It looks like the previous tinkerer tried to tap into an existing circuit trace, but did a terrible job with the soldering. I would recommend that you remove all of the charred-looking solder/flux that is present and replace it with fresh stuff. (Part of me wonders if they mistakenly used plumbing solder or something. This doesn't look good.) It should be completely fixable though!

More pictures would be appreciated. Where does the bodged red wire lead to?

If you haven't seen it already, you should watch @JDW's video on YouTube about recapping the Mac SE/30 analog board. I believe he covers replacing a similarly charred connector in his SE/30. There should also be information about replacement connectors somewhere in there hopefully.

Best of luck with your repairs!!

 

[YMK]

CRTs have a black graphite coating on them called Aquadag.

It needs to be there, but will readily come off if you go overboard with cleaning.

It looks like the residue on your CRT has just bled onto the Aquadag, so be careful.

 

[Kai Robinson]

This might be a good candidate for a reloaded Analogue board from @Kay K.M.Mods

 

[Elemenoh]

Here’s some info about the connectors They’re Molex 2.36mm Diameter Standard .093"

A premade pigtail would save you the hassle and expense of crimping your own. This one is just an example. There are a bunch of different length options.

Model: 2162911042
View Product

Otherwise you could get a male connector housing (I can’t tell what’s different between these two), pins, wire and a crimper tool.

Model 19091049
View Product

Model 39036044
View Product

Female socket

Model 15311046
View Product

Some of these might be available on eBay too.

 

[Paolo B]

I replaced both male and female connector on most of my compact Macs. Majority was charred. Not as bad as yours, but surely in bad conditions.

You don’t need to re-crimp the male connector, just extract the pins (there’s a dovetail lock) and replace the plastic part.

As for the female one, they come with the pins, so you will desolder and replace the entire connector.