LisaList2

Advanced search  

News:

2019.06.07 fixed NChat for the "Curve" theme, will eventually move it to its own page and add it to the default theme as well. Other plugins are next. see post in the Meta board for details

Pages: [1]   Go Down

Author Topic: Advice for removing the connector on the back of the CRT without breaking it.  (Read 181 times)

rayarachelian

  • Administrator
  • Sr. Member
  • *****
  • Karma: +11/-0
  • Online Online
  • Posts: 197
  • "But what's puzzling you is the nature of my game"
    • LisaEm

So in the other thread https://lisalist2.com/index.php/topic,18.0.html about the bleeding display, I mentioned that after a few minutes the display starts to bleed.
Any advice on how to physically remove the white ring connector on the back of the CRT tube neck without breaking the tube?

I'll be sure to let the CRT and capacitors drain for a while before I attempt this and I'll wear non conductive gloves and all that, but I just don't want to break the tube and lose the vacuum.
Do I just pull it towards the back case? How much force is needed? Should I wiggle it or move it straight back? I'm guessing the latter.Does the metal cover between the card cage and the CRT neck need to be removed?
Logged
Fate whispers to the warrior, 'You can not withstand the storm.'  The warrior whispers back, 'I am the storm.'

snuci

  • Full Member
  • ***
  • Karma: +4/-0
  • Offline Offline
  • Posts: 26

The white ring on the CRT neck pins does NOT need to come off if it is the one on the CRT neck tip that you are referring to.  You should be able to unplug it from the other end on the video board so you do not need to remove it.  I always worry about removing that as some have a small glass top in the middle that easily breaks.  I did remove one of these but found I did not need to.  The metal shiled behind the CRT neck does not need to be removed (in fact, I am not even sure how to do that).

Hope this helps.
Santo
Logged

blusnowkitty

  • Full Member
  • ***
  • Karma: +8/-0
  • Offline Offline
  • Posts: 27

Based on my experience with my 2/5:

- For easiest removal of the tube socket, yes, you'll want to pull the bracket/shield between the cage and tube neck. Be gentle when removing it as not only is it right next to the CRT neck, but there's a removable spade connector that's connected to the tube socket. Presumably that connector is a ground for the CRT. Be gentle, don't snag it otherwise you will risk breaking the tube neck. I ended up using a flathead screwdriver to pry it off.
- Once the shield is off, get a couple fingers on either side of the socket and apply firm, even pressure to both sides and pull straight back. Wiggling will greatly increase the risk that you'll snap the neck. If you hear a small snap, don't immediately panic - there's a small plastic tube on the keying pin in the center that I think is glued on to the glass and after all these years the glue breaks down and doesn't hold.

I'm not sure how the 2/10/Mac XL analog board is, but in the 2/5 there are three molex connectors. There's two two-pin connectors around the middle of the board, and a large 8-pin connector at the bottom near the card edge connector. Do not unscrew the analog board until you've removed that 8-pin connector - and it's going to be very tight and difficult to remove. It may be easier if you remove the CRT completely from the chassis but I wasn't feeling that adventurous so I just shoved my hand down in the corner (after discharging the tube!) and managed to wiggle it free.

The metal shiled behind the CRT neck does not need to be removed (in fact, I am not even sure how to do that).
If I remember correctly there's two or three screws up in the top of the chassis and one at the bottom of that shield.
« Last Edit: May 18, 2020, 11:18:48 am by blusnowkitty »
Logged

rayarachelian

  • Administrator
  • Sr. Member
  • *****
  • Karma: +11/-0
  • Online Online
  • Posts: 197
  • "But what's puzzling you is the nature of my game"
    • LisaEm

Thank you!
Logged
Fate whispers to the warrior, 'You can not withstand the storm.'  The warrior whispers back, 'I am the storm.'

rayarachelian

  • Administrator
  • Sr. Member
  • *****
  • Karma: +11/-0
  • Online Online
  • Posts: 197
  • "But what's puzzling you is the nature of my game"
    • LisaEm

So I was able to do this without killing myself, but sadly the video is still broken. I think I suspect I/O board - perhaps the contrast circuit.
I have another borked I/O board I'll try tomorrow, perhaps it has less damage, but I think the VIAs on it are messed up so might need to transfer them over.
I'll have to also swap the 800k SunRem I/O ROM as this Lisa has one of those.

I used a very long 10" 90' pliers which came in handy: https://www.amazon.com/gp/product/B00YQ7RWCW/ - I bough this for car work, but it went well here too.

I wasn't able to remove the CRT neck shield off because one of the screws was corroded badly. But I removed all the other screws so was able to push it out enough to get the white doughnut connector out. I used the tips of the pliers at the 9pm and 3pm marks to push it out.

The 8 pin cable from the flyback to the analog board was quite the mofo to get out. The pliers worked there too. This time I was ok with wiggling the connector left/right.

I also soaked a bit of paper towel in distilled vinegar and placed it on top of a corroded part of the stainless steel and within a few minutes it got rid of the haze, I wiped the excess off with water. Have to clean the rest of the case.

So to get to the point, if you have a Lisa that just displays a square white display with diagonal lines, it might not be the analog board.
Logged
Fate whispers to the warrior, 'You can not withstand the storm.'  The warrior whispers back, 'I am the storm.'

compu_85

  • Newbie
  • *
  • Karma: +2/-0
  • Offline Offline
  • Posts: 4

Are you taking the CRT out?

If you can't remove the metal cover over the CRT neck, space to remove the connector is tight. If you partially remove the CRT, it gives a lot more space to disconnect.

To remove it, just gently wiggle it off. It is not difficult to remove.

Here's a video I shot when changing the CRT on my 2/5: https://www.youtube.com/watch?v=Oauo8NQYomo

-J
Logged
Pages: [1]   Go Up