YES, you can repair/restore operation to the CP500 LCD display if you have lines or blank columns, etc. It Takes some effort, but, what do you to lose? This is for LCD failures, not backlight brightness or failure. I'm working on that.
The failures take place in the area of a spongy conductive interface between the circuit card and the glass LCD display element. If you dare, you can:
1. Remove the display circuit card from the front panel by disconnecting the cable and unscrewing it. I've experienced various foam and gasket materials you may want to replace or be careful of when separating the display from the front panel. These gaskets keep the light of the display controlled, so it looks good and doesn't bleed out around edges, etc.
2. Use a pair of pliers with a flat nose that is about the size of the metal tabs that protrude from the back side of the circuit card and gently untwist each metal tab connected to the metal cover holding the display glass. Don't bend them away from the circuit card, just untwist or straighten them just enough to release them. This could amount to just clamping the nose of the pliers on the tab and closing them to straighten the tab to its "unlocked" position, like it was before being twisted or bent over..
3. Carefully remove the metal cover to explose the LCD glass. Things might come apart and drop, so do this over something soft.
4. Gently separate the LCD glass from the circuit card. You will see two rubbery straps with a conductive matrix in them. They will either be stuck on the LCD glass or the circuit card.
5. The repair is to carefully clean the circuit card and LCD connections. I'm not sure you want to mess with the rubber contacts too much. I believe they are fragile. Use contact cleaner and make sure there is no residue.
6. Re-align everything and re-assemble the metal frame onto the display with the tabs back in place. You may need to keep some pressure on the assembly as you do this. You want to keep the rubber contacts aligned with the contacts on the circuit card and LCD glass.
7. Twist the metal tabs back to their original positions, working to not bend them away from contact points. They hold the pressure on the display sandwich. If they don't apply pressure holding the assembly together, your display may end up in a worse state.
8. You can try testing the display by hooking up the cable, but be sure you don't have anything conductive touching the circuit card. Or you can partially re-assemble and connect to test it. If all is good, re-assemble in earnest.
I've had success doing this to two displays so far. I've also swapped out backlights while in there as well. If there is interest, I can create instructions with pictures. Many older displays have this connection method and fail in the same way, but the LCD is still good, as is the driver board. You just neet to clean up the connections.
The failures take place in the area of a spongy conductive interface between the circuit card and the glass LCD display element. If you dare, you can:
1. Remove the display circuit card from the front panel by disconnecting the cable and unscrewing it. I've experienced various foam and gasket materials you may want to replace or be careful of when separating the display from the front panel. These gaskets keep the light of the display controlled, so it looks good and doesn't bleed out around edges, etc.
2. Use a pair of pliers with a flat nose that is about the size of the metal tabs that protrude from the back side of the circuit card and gently untwist each metal tab connected to the metal cover holding the display glass. Don't bend them away from the circuit card, just untwist or straighten them just enough to release them. This could amount to just clamping the nose of the pliers on the tab and closing them to straighten the tab to its "unlocked" position, like it was before being twisted or bent over..
3. Carefully remove the metal cover to explose the LCD glass. Things might come apart and drop, so do this over something soft.
4. Gently separate the LCD glass from the circuit card. You will see two rubbery straps with a conductive matrix in them. They will either be stuck on the LCD glass or the circuit card.
5. The repair is to carefully clean the circuit card and LCD connections. I'm not sure you want to mess with the rubber contacts too much. I believe they are fragile. Use contact cleaner and make sure there is no residue.
6. Re-align everything and re-assemble the metal frame onto the display with the tabs back in place. You may need to keep some pressure on the assembly as you do this. You want to keep the rubber contacts aligned with the contacts on the circuit card and LCD glass.
7. Twist the metal tabs back to their original positions, working to not bend them away from contact points. They hold the pressure on the display sandwich. If they don't apply pressure holding the assembly together, your display may end up in a worse state.
8. You can try testing the display by hooking up the cable, but be sure you don't have anything conductive touching the circuit card. Or you can partially re-assemble and connect to test it. If all is good, re-assemble in earnest.
I've had success doing this to two displays so far. I've also swapped out backlights while in there as well. If there is interest, I can create instructions with pictures. Many older displays have this connection method and fail in the same way, but the LCD is still good, as is the driver board. You just neet to clean up the connections.
Comment