Samsung A68QCP891X001 + Wei-ya M3129D01-7 - Horizontal offset

[Snufsen]

Hello

I recently purchased my first couple of cabs, two New Net City. One with a Toshiba monitor, and one with the monitor and chassi mentioned in the topic (Samsung A68QCP891X001 + Wei-ya M3129D01-7) which were salvaged and refurbished from an Egret3. I'm fairly good with software, but still a newbie on the hardware aspects of it all and have been struggling to sort out an issue with the Samsung cab.

Both cabs run a Taito Type X3 with the 1TB multi. On boot, the screen is offset horizontally, as seen in the attached image.

IMG_20211030_120625.jpg

I've been fiddling around quite a with the resolution settings (the multi run on top of Windows 10), which does give my a picture of the correct resolution, but offset. The odd thing (to me), is that if I leave it on for about 30-45 minutes, it's snaps into place. Problem seemingly resolved as long as it's on. If I reboot it, or shut it down and turn it on later, the image can be correct initially, then after five minutes it starts to jitter increasingly until it offsets again. But same here, if I wait a while it snaps back.

I have a NAOMI pcb that I have been testing with to make sure it's not purely hardware, and with that everything works fine.
I've been using QRes to set the resolution. If I echo the current running resolution, it report 640x480@59hz. I can't set it to 60hz through QRes it seems.
Can add that I've done the same configuration on both cabs, and the one with the Toshiba monitor runs fine, no issues. I understand that it's two completely different monitors and chassis which can make a world of difference, so there might be some additional configuring needed here, or some setting that should be different.
I have been trying a bit with ArcadeOSD without any real results or differences.

EDIT: Stupid me forgot to mention another potentially relevant detail. I've noticed there is a current coming through the vga connector. You can feel a constant tingle if you unplug the vga and touch the metal casing. I opened up the back cover with help of the seller and we took a look and found a ground that had come loose and reattached it, but it's still there. Could this have an effect on the problem?

Any ideas what might be off or something to try?
Thanks in advance

[flutesir]

I have the same problem of my Egret 3, the monitor is Samsung A68QCU970X with the chassis of Wei ya C3129D01-7, the screen will going to the left slowly first, after few minutes the screen will freaking crazy

A817D1A0-C489-42F5-83B7-2D3055A5FFE5.jpeg

Don’t know the reason but it keeps doing like that all the time

Any idea?

[RMRM]

It's most probably an Horizontal Hold problem. Have you tried the correspondent adjustment pot on the remote board?

[Snufsen]

I can get something similar (horizontal rolling?) which I fix by adjusting the pot for horizontal hold.

But the fact that it starts after a couple of minutes is similar. It can sometimes start rolling when the offset kicks in. I can stabilize the image with the pot, but it's still offset

[flutesir]

No matter how I adjusted the h hold, the screen still going to the left slowly in the first few minutes, then it freaks horizontally

[Snufsen]

Stupid me forgot to mention another potentially relevant detail: I've noticed there is a current coming through the vga connector. You can feel a constant tingle if you unplug the vga and touch the metal casing. I opened up the back cover with help of the seller and we took a look and found a ground that had come loose and reattached it, but it's still there. Could this have an effect on the problem?

(added to the original problem description as well)

[Snufsen]

After gathering information and finding some threads on the forums with similar sounding problems, I took the back cover off yesterday and looked around. Couldn't see anything obvious (to my untrained eye), so I booted it up and poked around at some of the connections to see if it changed anything, looking for e.g. cracked solder joints or similar.

In the end I realized that by poking a connector on the control board the image snaps into place. I failed to take any proper pictures, I dig not want to dig around too much while it was on. I'm still unsure how much I can poke around in there
I will try to take clearer once later today, but I tried to illustrate which connector seems to be troublesome. I'm not sure exactly what the connector goes to, but by poking the gray or white wire, on the end that connects to the board (not the vertical PCB) it seems to jump into place. So I guess it might be either the connector itself or the solder for it that's funky?

Is it just a matter of pulling the board out and investigating it underneath, or any other measures you suggest?


It still seems to be the case that by just leaving it alone for a while it adjusts itself.

(I've been using this manual, I believe it's the one for this chassis: https://wiki.arcadeotaku.com/images/4/4 ... manual.pdf)

[nem]

Is it just a matter of pulling the board out and investigating it underneath

Yup.

Good job on finding the cause.