Xezlec
Member
Hello all,
I've just added a thoroughly nonfunctional VT52 to my terminal collection. I would rather have a thoroughly functional VT52.
The beast does show a (terrible) raster image on the CRT as it is supposed to when the brightness is turned up enough, but no characters, and more ominously, pressing keys produces no click, nor does Ctrl-G sound the buzzer when set to local echo mode. So, basically, no sign of a brain. So far, I've checked all the power supply voltages, and they're what they should be.
Since the symptoms (to me, at least) suggest a logic board issue, I feel like I should grab a scope and dive into that. The thing is, the VT52 schematics from the internet don't seem to include a diagram showing the physical layout of the components on the main ("data path") logic board. They have layout diagrams for the other boards, just not the main one. I'm not sure if this is an omission on the part of DEC or whoever scanned the field maintenance print set. Also, the resolution on this scan is so unbearably awful that it is virtually impossible to read the labels on any of the components in the layout diagrams.
So what I'm getting at is: does anybody happen to have a paper copy (or a good, high-resolution scan) of the VT52 field maintenance print set? Also, any other pointers would be welcome. Otherwise, I'm just going to have to pull everything apart, follow all the traces, and make my own diagrams.
Thanks for any help!
I've just added a thoroughly nonfunctional VT52 to my terminal collection. I would rather have a thoroughly functional VT52.
The beast does show a (terrible) raster image on the CRT as it is supposed to when the brightness is turned up enough, but no characters, and more ominously, pressing keys produces no click, nor does Ctrl-G sound the buzzer when set to local echo mode. So, basically, no sign of a brain. So far, I've checked all the power supply voltages, and they're what they should be.
Since the symptoms (to me, at least) suggest a logic board issue, I feel like I should grab a scope and dive into that. The thing is, the VT52 schematics from the internet don't seem to include a diagram showing the physical layout of the components on the main ("data path") logic board. They have layout diagrams for the other boards, just not the main one. I'm not sure if this is an omission on the part of DEC or whoever scanned the field maintenance print set. Also, the resolution on this scan is so unbearably awful that it is virtually impossible to read the labels on any of the components in the layout diagrams.
So what I'm getting at is: does anybody happen to have a paper copy (or a good, high-resolution scan) of the VT52 field maintenance print set? Also, any other pointers would be welcome. Otherwise, I'm just going to have to pull everything apart, follow all the traces, and make my own diagrams.
Thanks for any help!