Author Topic: Advices needed to repair a CTM 644 monitor  (Read 1518 times)

0 Members and 1 Guest are viewing this topic.

Offline Nemesed17

  • CPC464
  • **
  • Posts: 13
  • Country: fr
  • Liked: 1
  • Likes Given: 1
Advices needed to repair a CTM 644 monitor
« on: 22:29, 06 May 19 »
 I would like to know how the cathodic tube of the monitor is fixed to the front frame. I am asking that because there is a gap between the frame and the tube on the right side (bottom and up) on my device, certainly due to a brutal treament during delivery. I am posting an image to illustrate.
I assume there are 4 screws that hold the tube, but I find the schematic of the service manual  a little bit unclear ; could any of you confirm this ?
Apart from that, the monitor works fine.
I would like to open the case and fix the problem even if the discharge procedure worries me a lot.
Thanks for your help.
 

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 12.343
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 4631
  • Likes Given: 484
Re: Advices needed to repair a CTM 644 monitor
« Reply #1 on: 19:27, 07 May 19 »
It's held in place with a metal bracket in each corner. If you open the case you can see the screws that hold the brackets to the case, but if the gap happened due to brute force, then there's a good chance that the plastic pillars have cracked open and the screws are no longer doing anything.

Bryce.
 

Offline Nemesed17

  • CPC464
  • **
  • Posts: 13
  • Country: fr
  • Liked: 1
  • Likes Given: 1
Re: Advices needed to repair a CTM 644 monitor
« Reply #2 on: 11:47, 08 May 19 »

I was afraid of that, so I will not open the case, the risk is not worth it. Do you think there is any danger in letting the tube hold only with 2 screws on the same side? I reduced the gap applying a succion cup and puling the screen.
And thanks a lot for your answser!

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 12.343
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 4631
  • Likes Given: 484
Re: Advices needed to repair a CTM 644 monitor
« Reply #3 on: 12:13, 08 May 19 »
The biggest danger would be that the other brackets are also damaged and the screen could cave in completely at some time. If the monitor was powered at the time, the neck-board (PCB on the back of the tube) could short to something on the mainboard and cause fireworks. I would open the monitor, remove the screws, glue the pillars and put the screws back in. There is also the chance that a screw may have fallen out completely and is loose inside the case which could also cause fireworks.

Bryce.

Offline Nemesed17

  • CPC464
  • **
  • Posts: 13
  • Country: fr
  • Liked: 1
  • Likes Given: 1
Re: Advices needed to repair a CTM 644 monitor
« Reply #4 on: 10:39, 09 May 19 »
I get your point. The main problem for me is precisely that I have to open the case, because I guess I need to discharge the tube (and maybe the condensators) afterwards to work in security, a procedure I have never done. I am not at ease with electricity, since I was badly electrocuted by a faulty fridge when I was a teenager.  I'll pass on this and try my luck in buying a "new" monitor.
Thanks again for your concern.

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 12.343
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 4631
  • Likes Given: 484
Re: Advices needed to repair a CTM 644 monitor
« Reply #5 on: 16:09, 09 May 19 »
You definitely don’t need to discharge the tube and the capacitors are far from the area you need to look at.

Bryce.

Offline Nemesed17

  • CPC464
  • **
  • Posts: 13
  • Country: fr
  • Liked: 1
  • Likes Given: 1
Re: Advices needed to repair a CTM 644 monitor
« Reply #6 on: 00:45, 13 May 19 »
Ok, I will try the repair.

Offline Nemesed17

  • CPC464
  • **
  • Posts: 13
  • Country: fr
  • Liked: 1
  • Likes Given: 1
Re: Advices needed to repair a CTM 644 monitor
« Reply #7 on: 23:11, 19 May 19 »
You were right Bryce, one of the bracket was splitted (but not broken to pieces) and another one was misaligned. I unscrewed the 4 screws and recentered the whole, and screwed back. The gap is significanly recduced to a minimum and the screen seems to hold tight.Thanks again

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 12.343
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 4631
  • Likes Given: 484
Re: Advices needed to repair a CTM 644 monitor
« Reply #8 on: 00:29, 21 May 19 »
Congratulations, at least you can now use it with confidence instead of worrying that it could fall apart at any minute. It was worth taking a look.

Bryce.

Offline GUNHED

  • 6128 Plus
  • ******
  • Posts: 2.693
  • Country: de
  • Reincarnation of TFM
    • FutureOS - The quickest OS for the CPC and Plus
  • Liked: 1265
  • Likes Given: 2961
Re: Advices needed to repair a CTM 644 monitor
« Reply #9 on: 00:52, 21 May 19 »
Let the tube stand for some weeks in case you don't need it then it's discharged for a good part.
http://futureos.de --> Get the revolutionary FutureOS (Update: 2021.01.24)
http://futureos.cpc-live.com/files/LambdaSpeak_RSX_by_TFM.zip --> Get the RSX-ROM for LambdaSpeak :-) (Updated: 2021.07.15)