fachat
Experienced Member
Subject says it all basically. I have a broken 4032 (9" model, no CRT) and I think the screen is broken. It does not heat up and nothing is shown. The CPU however is working (to some degree at least, I've scoped the pins, and the screen output also looks all black except for a very small part - which could be the READY prompt).
When I started it the first time, it did not start up. I measured the transformer and it did not give much voltage (around 1-2V AC) ... until suddenly a sizzling noise appeared, and a little smoke was coming from under the transformer :-(
I took it all apart but could not see anything, so I tried powering on the transformer only (without board and monitor) and got about 16V AC. Then I put the board back in and it seemed to work as well (as I said scoped the signals).
Only when I put on the monitor, it just stays black, the tube does not heat up (I think - I cannot see any glowing light through the back as I remembered it should be)
As it is, I have a surplus 12" CRT, and looking at the connectors, they look very much alike (GND, AC power supply, std. PET video connector). Looking at the schematics the only thing I see is that the 12" model has the video signal inverted (5V is white here, 0V is black, on the 9" it's the other way round).
Has anyone tried that before?
Alternatively I have another broken 3032 that I could salvage (but I also wanted to restaurate that), and maybe even try to fix the CRT.
Thanks for any help
André
When I started it the first time, it did not start up. I measured the transformer and it did not give much voltage (around 1-2V AC) ... until suddenly a sizzling noise appeared, and a little smoke was coming from under the transformer :-(
I took it all apart but could not see anything, so I tried powering on the transformer only (without board and monitor) and got about 16V AC. Then I put the board back in and it seemed to work as well (as I said scoped the signals).
Only when I put on the monitor, it just stays black, the tube does not heat up (I think - I cannot see any glowing light through the back as I remembered it should be)
As it is, I have a surplus 12" CRT, and looking at the connectors, they look very much alike (GND, AC power supply, std. PET video connector). Looking at the schematics the only thing I see is that the 12" model has the video signal inverted (5V is white here, 0V is black, on the 9" it's the other way round).
Has anyone tried that before?
Alternatively I have another broken 3032 that I could salvage (but I also wanted to restaurate that), and maybe even try to fix the CRT.
Thanks for any help
André