Author Topic: CTM-644 convergence problem  (Read 652 times)

0 Members and 1 Guest are viewing this topic.

Offline alextp77

  • CPC464
  • **
  • Posts: 5
  • Country: fr
    • Awards
CTM-644 convergence problem
« on: 06:38, 30 May 21 »
Hello,This is my first post on this forum (which seems very nice) as I've got a CPC6128 and a CTM-644 monitor, 2 days ago.I'm very impressed indeed, it is by far a better experience than with any emulators and the not perfect LCD monitors.

Anyway, the monitor seems to work nicely, except that there are some convergence problems. The red color looks out of focus around the lower right corner. That make things look blurry.How can I fix this ? I know there are some rings to turn inside the monitor, would they help, and if yes, which one should I try to adjust ?
At last, I know that CRT are extremely dangerous and I never go beyond adjusting the focus and G2 on them. I know what not to touch, but are those rings a danger if I touch them with the hands ?
Thank you !
like
0
No reactions

Offline Animalgril987

  • Supporter
  • CPC6128
  • *
  • Posts: 230
  • Country: gb
    • Awards
Re: CTM-644 convergence problem
« Reply #1 on: 13:58, 30 May 21 »
Welcome to the forums!


I'm sure somebody on here will be able to advise you.


(Say @Bryce three times, and he'll usually appear!!) :D :D

like
0
No reactions

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 12.470
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
    • Awards
Re: CTM-644 convergence problem
« Reply #2 on: 14:49, 30 May 21 »
Once usually does the trick. I'd suggest you degauss the CRT first before you start fiddling around inside. It may have just been stored beside a big speaker or something. As for touching things inside a running monitor - My advice : Don't!

Bryce.
« Last Edit: 15:10, 30 May 21 by Bryce »
like
0
No reactions

Offline alextp77

  • CPC464
  • **
  • Posts: 5
  • Country: fr
    • Awards
Re: CTM-644 convergence problem
« Reply #3 on: 16:07, 30 May 21 »
Once usually does the trick. I'd suggest you degauss the CRT first before you start fiddling around inside. It may have just been stored beside a big speaker or something. As for touching things inside a running monitor - My advice : Don't!

Bryce.
I will follow your advice, my life's more important that this old piece of electronic, or at least I hope so -_-As for degaussing it, I can only perform it by placing a PC monitor in front of it, probably not the best way ...
Thank for the answer :)
like
0
No reactions

Offline alextp77

  • CPC464
  • **
  • Posts: 5
  • Country: fr
    • Awards
Re: CTM-644 convergence problem
« Reply #4 on: 17:48, 30 May 21 »
I've got another question ...
I noticed that if I touch the 5v cable a little bit, the monitor brightness slightly change. What's the relation between this cable and the monitor brightness ?Is it worth (I guess it is) to redo the soldering where the cable is plugged inside the computer ?
Thanks !
like
0
No reactions

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 12.470
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
    • Awards
Re: CTM-644 convergence problem
« Reply #5 on: 21:22, 30 May 21 »
Most likely just dirt on the contacts, but could also be a partial break in the cable. The brightness is changing because the CPC is getting more power when the connection is good. Try cleaning both side of the 5V connector / socket.

Bryce.
like
0
No reactions

Offline alextp77

  • CPC464
  • **
  • Posts: 5
  • Country: fr
    • Awards
Re: CTM-644 convergence problem
« Reply #6 on: 23:15, 30 May 21 »
Most likely just dirt on the contacts, but could also be a partial break in the cable. The brightness is changing because the CPC is getting more power when the connection is good. Try cleaning both side of the 5V connector / socket.

Bryce.
The motherboard had a bath yesterday, hot water and soap. So from what you said, it must be a defective cable. Anyway, if I don't touch it, everything work great, so I will leave it as it is for now.Thank you.
like
0
No reactions

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 12.470
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
    • Awards
Re: CTM-644 convergence problem
« Reply #7 on: 09:28, 31 May 21 »
Soap and water won't clean contacts. In fact these soap and water baths do nothing positive for the electroonics, they just make the PCB look slightly better for you and may even make the situation worse. You need to use proper contact cleaner on the contacts.

Bryce.
like
0
No reactions

Offline alextp77

  • CPC464
  • **
  • Posts: 5
  • Country: fr
    • Awards
Re: CTM-644 convergence problem
« Reply #8 on: 14:35, 31 May 21 »
Soap and water won't clean contacts. In fact these soap and water baths do nothing positive for the electroonics, they just make the PCB look slightly better for you and may even make the situation worse. You need to use proper contact cleaner on the contacts.

Bryce.

Ahah, all those youtube videos ... like the fact that you can fix everything with toothpast -_-

Will Isopropyl alcohol do it ?
like
0
No reactions

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 12.470
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
    • Awards
Re: CTM-644 convergence problem
« Reply #9 on: 16:36, 31 May 21 »
Yes.

Bryce.
like
0
No reactions