Problem Strange CRT issue, displays a stable but chopped up image

Symphony

Symphony

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This isn't quite arcade repair I'm looking for, but it's adjacent enough that hopefully that's alright to be posted here.

I've had an oddball CRT monitor kicking around for a while now that I've never been able to fully test. Internally it is very clean and shows practically no use, but no matter what I hook up to it - either 15 or 31khz - it won't display a complete image. It has adjustment dials on the back for phase, sync and such for both vertical and horizontal, and I can get it to lock to a stable (non-rolling) image, but what always happens is the picture is stretched, chopped up into like 4 segments and they are not only located in the wrong areas of the screen but also overlap each other. There is absolutely no documentation online of this monitor existing, so I dunno if I'm just not feeding it the right sync or if it only wants a very specific signal that I can't give it with the gear that I have.
 
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cliff_poole

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Could it maybe have been an old graphics workstation monitor ?. The BNC connectors are what is making me think that. They sometimes used weird sync. I once had a couple of old IBM XGA monitors that I couldn't get to work with anything.
 
Symphony

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cliff_poole said:
Could it maybe have been an old graphics workstation monitor ?. The BNC connectors are what is making me think that. They sometimes used weird sync. I once had a couple of old IBM XGA monitors that I couldn't get to work with anything.
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Possibly, the only useful identification on it is Microvitec, but the only thing I could find is that some of those models were multisync, I thought I found something a while back that said that range was for graphics but I can't locate that any more.
 
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I bought a sony recently and that came from MOD the guy said

Just noticed something, Above Sync it says Out or Term for Terminated, just had a thought about old Terminals we worked on that were linked like that and wondered if you need to terminate the output

googled and found this

Does the Sync Out on a BVM need a 75 ohm BNC terminator?​


I have the 75ohm terminators for the RGB outputs but I'm unsure if you also should connect one for the sync output

If you are sending a monitor sync and it isn't being looped through it should be terminated. Some monitors have a termination switch, others are auto-terminating, and yet others need a 75 ohm BNC terminator.
 
Symphony

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Bods said:
I bought a sony recently and that came from MOD the guy said

Just noticed something, Above Sync it says Out or Term for Terminated, just had a thought about old Terminals we worked on that were linked like that and wondered if you need to terminate the output

googled and found this

Does the Sync Out on a BVM need a 75 ohm BNC terminator?​


I have the 75ohm terminators for the RGB outputs but I'm unsure if you also should connect one for the sync output

If you are sending a monitor sync and it isn't being looped through it should be terminated. Some monitors have a termination switch, others are auto-terminating, and yet others need a 75 ohm BNC terminator.
Click to expand...
Oh, good call. I have a few of those somewhere so it's worth a shot. I thought the "Term" part meant Terminal, like that row of outputs was for chaining into a terminal.
 
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Bods

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Symphony said:
Oh, good call. I have a few of those somewhere so it's worth a shot. I thought the "Term" part meant Terminal, like that row of outputs was for chaining into a terminal.
Click to expand...
Not sure if it will work but yeah deffo worth trying, even better if you have some, only going on what that said as i've not done anything much with pvm or bvm yet
 
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