I could use some help troubleshooting this monitor. I think it's some sort of horizontal circuit problem, but I'm not sure.
Rather than trying to describe it, I've posted a video on YouTube: https://youtu.be/cJ4ZUrg0ATA. It starts out OK but within 45 sec or so things start to go wrong, and by 2:00 it's settled.
It's been working fine, at least in 15k mode, since I installed it in an empty Golden Tee cab. It's connected to a Pandora's Box 4 through the JAMMA harness (since I couldn't get it working in VGA/31k mode). It's also been hooked up with a World Class Bowling PCB and worked fine. Switching between the two required some minor tweaks to the Horiz settings on the chassis, but otherwise no problems.
Probably got 10 good hours of use before it started acting up. I'd left it on for several hours after leaving the house for a while and when I got back it was all screwy, and it hasn't been right since.
The problem seen in the video is about the same in both 15k and 31k modes, although in 31k it's bad right from the start, while in 15k mode it starts out OK then goes bad within a minute.
At about the 1:55 mark in the video I adjusted the H POS pot a bit which seemed to bring the picture back, but only for a few seconds.
I just installed a cap kit hoping it would solve this. There's 4 caps I couldn't replace because they didn't come in the kit (C55 on the main PCB, and C201, 219, 220 on the neck board).
The B+ at R33 is 69vdc. I don't know which model of board I've got so I'm not exactly sure what the setting should be, however, I couldn't adjust it lower than 64vdc or above 70vdc for some reason.
I also replaced the H POS pot.
I installed a 12v fan blowing over the neck board and it seems to keep things fairly cool so I don't think it's an overheating problem.
I know I could reach out to Rick at Nieman Displays but I thought I'd try here first.
There's a couple different schematics out there, I've attached the one that seems to match my setup.
Any ideas?
Rather than trying to describe it, I've posted a video on YouTube: https://youtu.be/cJ4ZUrg0ATA. It starts out OK but within 45 sec or so things start to go wrong, and by 2:00 it's settled.
It's been working fine, at least in 15k mode, since I installed it in an empty Golden Tee cab. It's connected to a Pandora's Box 4 through the JAMMA harness (since I couldn't get it working in VGA/31k mode). It's also been hooked up with a World Class Bowling PCB and worked fine. Switching between the two required some minor tweaks to the Horiz settings on the chassis, but otherwise no problems.
Probably got 10 good hours of use before it started acting up. I'd left it on for several hours after leaving the house for a while and when I got back it was all screwy, and it hasn't been right since.
The problem seen in the video is about the same in both 15k and 31k modes, although in 31k it's bad right from the start, while in 15k mode it starts out OK then goes bad within a minute.
At about the 1:55 mark in the video I adjusted the H POS pot a bit which seemed to bring the picture back, but only for a few seconds.
I just installed a cap kit hoping it would solve this. There's 4 caps I couldn't replace because they didn't come in the kit (C55 on the main PCB, and C201, 219, 220 on the neck board).
The B+ at R33 is 69vdc. I don't know which model of board I've got so I'm not exactly sure what the setting should be, however, I couldn't adjust it lower than 64vdc or above 70vdc for some reason.
I also replaced the H POS pot.
I installed a 12v fan blowing over the neck board and it seems to keep things fairly cool so I don't think it's an overheating problem.
I know I could reach out to Rick at Nieman Displays but I thought I'd try here first.
There's a couple different schematics out there, I've attached the one that seems to match my setup.
Any ideas?
Attachments
Last edited: