Sync Stripper issues (PVM 2950Q)

bartre

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so I'm wanting to add a sync stripper to my Scart -> BNC cable following this guide:
http://www.mmmonkey.co.uk/composite-sync-stripper-lm1881/

I've put it together, grounded to pin 4 on the scart socket, pulling power from pin 8, and pulling video from pin 20 on the socket and passing it out through the sync BNC connection.

problem is, it's no good.
after a little chat help, I thought it might be power, so I added a wall PSU that's providing 8.4v under load (and my genesis Model 1 by the look of it)

but still, no luck.
any clues?
 
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Xian Xi

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Just to make sure, you've used the RGB on that monitor before, correct?
 

bartre

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I have not, but it was purchased from a member here, so I don't think it's the problem.
as is, I get a rolling picture, so I know it's a sync issue, right?
 

Kid Panda

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I have not, but it was purchased from a member here, so I don't think it's the problem.
as is, I get a rolling picture, so I know it's a sync issue, right?

You broke the monitor putting it in the car, I seen't it!
 

ballzdeepx

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Just curious but what TV is it, and are you using H&V sync BNCs or just one?
Also what consoles work without the stripper, or if none, which ones are you trying to get to work?
 

skate323k137

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Dumb question but if it's a PVM have you set the ext sync option/switch?

Knowing your monitor and setup could help us help you. Also when in doubt check or replace the caps/resistor in the lm1881 circuit... they only cost pennies to rule out.
 

bartre

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okay, some more information (at least the information I know)
Monitor - PVM 2950Q
Consoles tested - RGB twin Famicom, RGB PC Engine, Model 1 Genesis (none Worked)

skate - what do you mean by ext sync option/switch?

ballz -my adapter only has one output for sync, so I'm not sure how to answer.

oh, and I know the monitor itself is good (at least to a degree) I hooked up my 64 and PS2 via S-video and they looked great.
 

Xian Xi

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Like mentioned, if it's rolling it means there's a lack of sync/incorrect sync rate. If it's a PVM/BVM like skate said, you need to push the int/ext sync button.
 

skate323k137

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ext sync is an option on PVMs to tell it to actually use the sync from the sync BNC input. Otherwise it can look for sync on green or other methods.

Depending on the model it's either in a menu or a physical switch. According to the manual for the 2950Q it auto-selects this, which is different from any sony monitors I've owned.

tl;dr your monitor should already automatically find the sync source, so carry on.
 

Opethian

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ask arcade game or themot they got your model working with the same problems at first.
 

bartre

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okay, so Does it matter which ext sync i plug into?
there's HD/Comp and VD, which according to the manual represent H sync/Composite Sync or Vertical Sync.

which also makes me think, do I need a stripper?
and does it need power of exactly 5v or 12v, or is it okay if it's simply in that range?
 

wyo

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Hmm, some more ideas/suggestions... Within 5v-12v range is fine. 4.9v or 12.1 won't work. I've never owned a 2950 but IIRC ballz had/has one so he might be able to help more. Try the SCART to BNC cable without a sync stripper and with a SCART wired to c-sync. Also, check the menu options/buttons thoroughly on the monitor. Connect sync to H input, not V. Try with the sync stripper on a different monitor. If you get a picture, it's working, so must be an issue with the 2950. Need to do some process of elimination here.
 

DanAdamKOF

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Pretty sure 2950Q doesn't need to be told to use Ext Sync, it's automatic. I've never had to mess with that on mine.

CSync gets plugged into the HSync jack as wyo said.
 

PunkicCyborg

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I had a bad LM1881. Test the output with a probe to make sure it's passing data
 

ballzdeepx

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I have a 2950 and it's picky as heck, and seems to prefer composite video sync. First off just to rule out something, have you tried putting the sync BNC on each of the sync inputs or are you only ever using one?
The monitor has either a component or RGB setting for this input so make sure you don't have it on component on accident, hit RGB on the remote.

Some of the consoles I've had to add some resistors to the sync line for their Scart cables (Saturn and my MVS come to mind) but some systems just worked fine without like model 1 genesis, snes, PCE, N64. All of the cables I used were wired for composite video sync.

Honestly the best thing I ever did with this monitor was get a Sync Strike unit from VBA when he sold it. I don't know what wizardry the thing does over a traditional LM1881, but it handles everything I've thrown at it, and I never had to fiddle with a sync stripper circuit again.
 

shadowkn55

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Are you using a female scart to bnc cable or a male connector plugged into a scart box?
 

bartre

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okay, progress update-
I rebuilt the circuit, removed the power adapter, and double checked all the connections in the adapter.
I got everything checked out, and viola!
works great now.

I will say, when I play famicom games, i get a bit of an audio buzz that isn't present (at least i can't notice it) when I'm playing Genesis, any clues?
 

NEO G-TRON

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I have a few of those PVM 2950's and they do in fact require a sync stripper added to the composite sync on the your Scart to BNC cable in order to have full compatibility without any issues.
 

Xian Xi

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I will say, when I play famicom games, i get a bit of an audio buzz that isn't present (at least i can't notice it) when I'm playing Genesis, any clues?

From what I was told, buzzing is normal from an NES/Fami. Something about the audio via the CPU or something.
 

joe9

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Is there any way to set a 2950Q to external sync mode?
 
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