PVM-2950 RGB sync issues?

joe8

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I have problem with a 2950QM. The RGB picture is mostly garbled. But if you're playing a certain game, you can at least tell that it's that game. The composite and component work fine.
It was in storage for a while, before that, the RGB was working OK.

I use it with a CMVS and an Arcade Forge LM1881 sync stripper (SCART->stripper->VGA->BNC cable). I have used this with another PVM in the last week, and it worked OK for RGB.
Does anyone know how to fix this problem?
 
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awbacon

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I have problem with a 2950Q. The RGB picture is mostly garbled. But if you're playing a certain game, you can at least tell that it's that game. The composite and component work fine.
It was in storage for a while, before that, the RGB was working OK.

I use it with a CMVS and an LM1881 sync stripper (SCART->stripper->VGA->BNC cable). I have used this with another PVM in the last week, and it worked OK for RGB.
Does anyone know how to fix this problem?

Stupid question but have to ask....you do have the external sync button toggled on it right?

Is it on all RGB inputs or just a single console / arcade board? More info might point to an issue, but perhaps that model syncs on a signal your cables aren't set up to carry?
 

joe8

margarine sandwich
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Stupid question but have to ask....you do have the external sync button toggled on it right?

Is it on all RGB inputs or just a single console / arcade board? More info might point to an issue, but perhaps that model syncs on a signal your cables aren't set up to carry?
The 2950QM is automatically set to external sync (there is no button to set it to external sync). I think the 2950QM has a hidden menu, I'm trying find out to get to it. Not sure if it will help, though.

The problem with a garbled picture (using RGB) is the same on three consoles I've tried, an AES, a CMVS and a PS2.

I have had the RGB working fine on a 14" Sony PVM (with the Arcade Forge stripper and BNC cable I'm using now), about a week ago. That monitor had a button to turn on external sync. I've had the same stripper & cable setup working previously (a few years ago) with the 2950QM, but sometimes I had to change the connections, to get them right, so that it would work (it didn't always work straight away). The BNC cable has two wires (black & grey), which I think are both for sync, and there are two BNC inputs on the monitor for sync (HD/COMP, and VD), so there are multiple ways you can connect the black & grey wires, or you can just connect one of them.
 
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awbacon

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The 2950QM is automatically set to external sync (there is no button to set it to external sync). I think the 2950QM has a hidden menu, I'm trying find out to get to it. Not sure if it will help, though.

The problem with a garbled picture (using RGB) is the same on three consoles I've tried, an AES, a CMVS and a PS2.

I have had the RGB working fine on a 14" Sony PVM-14M2A (with the Arcade Forge stripper and BNC cable I'm using now), about a week ago. That monitor had a button to turn on external sync. I've had the same stripper & cable setup working previously (a few years ago) with the 2950QM, but sometimes I had to change the connections, to get them right, so that it would work (it didn't always work straight away). The BNC cable has two wires (black & grey), which I think are both for sync, and there are two BNC inputs on the monitor for sync (HD/COMP, and VD), so there are multiple ways you can connect the black & grey wires, or you can just connect one of them.

Strange. I’d check the service manual. Sounds like it looks for sync on a signal your wires aren’t providing.

Compare against the service manual for your 14 inch PVM and see if you can find a difference
 

joe8

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Strange. I’d check the service manual. Sounds like it looks for sync on a signal your wires aren’t providing.

Compare against the service manual for your 14 inch PVM and see if you can find a difference
The manual for the 14" PVM says to "connect the reference signal from a sync generator to this connector" ("EXT SYNC"). There is only one input connector for external sync.
I don't actually have the 14" PVM any more, which makes things more difficult.

According to the manual for the 2950, it has two input connectors for external sync (EXT SYNC):
HD/COMP (BNC) Connect to the H sync signal or composite sync signal.
VD (BNC) Connect to the V sync signal output.
 
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awbacon

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The manual for the 14" PVM says to "connect the reference signal from a sync generator to this connector" ("EXT SYNC"). There is only one input connector for external sync.
I don't actually have the 14" PVM any more, which makes things more difficult.

According to the manual for the 2950, it has two input connectors for external sync (EXT SYNC):
HD/COMP (BNC) Connect to the H sync signal or composite sync signal.
VD (BNC) Connect to the V sync signal output.

Hmm. Head scratcher. I’d check on reddit under the PVM subreddit. Some of the people on there might know about that particular model.
 
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