Here a story how I replaced a CRT screen with LCD one.
Thanks a lot to the document named "TDS 520B Mod CM Digitizing Oscilloscope Component Service Manual", it reveals some details on scope's guts.
After my lovely CRT screen became a piece of glass, I started to look for alternatives our Chinese brothers can offer.
Not too many.
According to the Service Manual, the scope resolution is 640x480. But the problem is that nowadays it is not very easy to find an affordable LCD with such native resolution. 6.5" 640x480 screens are mostly used in cars and industrial equipment so they are not as cheap as widescreen 800x480 ones. For example, 4:3 screens start from $150 when 16:9 start from $60 with controller.
So I bought AT070TN90 7" 800x480 LCD panel with a controller for less than $70 with shipping from a US seller on eBay.
Luckily controller has 4:3 mode so LCD can display 640x480 picture without any pixel transformation issues. But the bad thing about 4:3 mode is that controller fills unused areas with blue. It sucks. I need to cover it with something. But I have to make a front panel for this screen anyway.
Finally I got new screen working. It took some time to complete. So here what else I needed:
- anodized aluminium panel (eBay)
- Radioshack perfboard
- 12V DC/DC converter (eBay)
- 1-ft VGA cable (eBay)
- aluminium bar to make nuts
- #4-40 tap
- some wires, screws, and washers
- epoxy glue
- nylon PCB stands
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| AT070TN90 |
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| Realtek LCD controller board |
Frame was cut from anodized aluminium:
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| Last test |
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| Radioshack perfboard, 12V DC/DC converter and LCD controller with 1-ft VGA cable |
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| Where to get some power for the LCD |
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| OSD menu buttons. LCD power wires connected to J574 are on the top. |
Finally I put it all together:
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| The resutl |
But for some strange reason some pixels at the bottom of the screen are missing. No way to correct it using OSD menu, but it doesn't affect the signal graph area.
I'm satisfied (but CRT screen was much better). It is a nice feeling when you bring a good device back to life.
