Rolling picture on a Neotec 2515c

[Crowquill]

I have a Primal Rage cab that I'm using to swap out JAMMA boards. It has the original Neotec 2525c 25" monitor. I have about half a dozen PCBs that come up fine with no problems at all. But there are a few that keep rolling horizontally no matter how much I adjust the horizontal hold. I can get them to slow down and almost stop, but then they "pick up speed" again.

The two I'm having problems with are Darkstalkers (CPS-2), and Zero Team. Suprisingly, the suicide batteries haven't gotten to either of these yet.

Is there any "fine-tuning" that can be done on this monitor?

I posted this over at the KLOV boards, too, but haven't gotten much response.

[grantspain]

is it only the capcom games rolling?and is it one motherboard?
i have had situations in the past where by for some reason one manufacturers board does not lock with one manufacturers monitor,one way i overcame this was by linking the sync wires.
i had one board(gaelco world rally) that would never lock on a kortek ktmf no matter what i tried

[Crowquill]

I have two different PCBs that are exhibiting the same problem. At first I thought it might even be something wrong with the CPS-2 A board, but Zero Team (a Seibu Kaihatsu game) does the same thing.

Darkstalkers runs at 59.63Hz which I thought might be the issue, but Zero Team runs at the standard 60 Hz and has the same issue. While I haven't found anything that really states it, I'm guessing the horizontal hold is what adjusts the frequency, right?

Mr Driller 2, Soul Edge, CombatTribes, and Simpsons Bowling all work fine.

NBA Jam comes up, but it's really dark on screen. This one I'm currently chocking up as probably having something wrong with the PCB (although if anybody has any ideas I'd love to hear them).

I'm hoping to pick up a JAMMA cabinet with a working monitor at one of the upcoming auctions. That would definitely make it easier to troubleshoot if I knew they worked in a different cabinet/monitor.

[grantspain]

i know its a long shot but you have checked your +5 volts is around 5.05 to 5.10 on the edge connector

[Crowquill]

I'll check it tomorrow. Is it best to check it with just the harness or should it be attached to a PCB. I'm assuming it needs the load of a PCB.

[grantspain]

always read voltages under load otherwise you will get a false reading

[Crowquill]

That's what I was thinking. It was up a bit high at 5.27V. Tuned it back down to 5.07, but still no change in either game.

[grantspain]

well it was worth a shot,have you tried linking the 2 sync wires yet?

[modessitt]

I was thinking you should try removing the vertical sync wire from the monitor plug and see if that makes a difference.  I know some new monitors that recieve composite sync won't sync unless only the horizontal sync is hooked up, even though older monitors would and do require both horizontal and vertical syncs attached to the composite signal....

Another thing to consider is whether all these games use the same type of sync (positive or negative) as this will cause sync issues as well - i.e. hooking a board that generates composite negative sync to the positive sync connector on the monitor.....

[Crowquill]

I'l check out the sync wiring tonight. I kind of expect this thing to be hooked up with just negative sync since it was built in '94, but who knows. This is one reason that I thought this cab would work pretty well to swap JAMMA games. I figured as late as this cabinet was built, things were much more standardized then. But then again, Atari skipped some of the pins on the JAMMA harness that Primal Rage didn't use. The operator had added in start buttons when it was converted to Tekken 3, but there still isn't a pin for -5V. So far I haven't had any PCBs that need -5V.

Is there any database or way to find out which games used positive or negative sync?

[modessitt]

Find the manual online and check the wiring diagram for which pins the sync goes to....

[grantspain]

i found this if it helps http://files.flipperspill.no/Support/Arcade/Monitors/Neotec/NT-2515C.pdf

[smalltownguy]

Necro thread bump

I have this exact same problem. Does anyone know about these Neotec monitors? Mine won't sync to any of the CPS2 games I put on it.

[Yeltsew7]

smalltownguy, if you are using groovymame/crt_emudriver, take a look here: http://forum.arcadecontrols.com/index.php/topic,138857.0.html .

You may need to update your VMmaker

EDIT:  wait, are you talking about MAME or with real PCBs?