New Unused Pentranic Monitor Shimmering Issue.

[lettuce]

So i have this new unused Pentranics monitor, Model 1125 which is on a CH-288 chassis and the tube is a Licus (yeah ive never heard of them either)....



I have notice im getting a kind of interference or unstable shimmering effect, heres a video showing the issue.....



Im using a Raspberry Pi with the RGB-PI scart cable...



and a cable i made up that attaches directly to the chassis video pins and to a female scart socket....



The cable i used does appear to be shielded as it had that blue foil shield, so im almost sure its not the cable im using that causing these issues!?

So any ideas what could be casing this unstable picture effect??

Also is it normal for brand new monitors to smell?

[Taiyaki]

To be honest that doesn't look that bad. It could be normal internal interference on that model. You'd have to find someone with the exact same model and ask him to test (in view of what crt this is, probably not going to be easy). My pro monitors also had some degree of shimmering (although generally was more isolated around the edges), in fact I don't think I've ever had a crt that didn't have some amount of shimmering or pixel shake as some call it.

[lettuce]

Oh really, i cant say ive noticed it on my CRT's in the past.

One odd thing is this video i captured using the NES this time (RGB modded)....

https://youtu.be/9JK-OpqF7UU

If you watch the last part where the tops of the scaffolding seem to change from a slanted angle to straight each time frequency refreshes bar rolls down the screen. To the human eye these scaffolding are flickering back and fourth very quickly but this isn't picked up on the camera and appears slower

Also should the frequency bar be going down the screen not up???

[Josh128]

Man, this looks like a similar type of interference caused my my Keene Scart commander on my plasma set-- on CRT is was a bit different, but did make horizontal line/intensity flickers that rolled down the screen. Can you try another source?

My fairly educated guess is its a sync signal level issue. You can try to attenuate or boost the sync depending on if its currently 75ohm or TTL level. Do you know which it is?

[Taiyaki]

The first video you uploaded did not stand out as abnormal to me but the second one is definitely more curious. Do you get this while no game system is up when navigating the menus?

One thing worth looking into is dirty power, it's not likely to be the case but I think it's one possibility for faint horizontal rolling lines like that.

Another possibility that comes to mind would be due to an off frequency video input that doesn't fully agree with the monitor. For example in the US the NTSC standard is strict at around 59.94hz if I remember correctly. If a game runs a little off that (like say 59.35hz) it might cause faint/light video anomaly. In my experience the anomaly itself would vary depending on the set and its quirks, there is the possibility that on that set it would manifest itself that way.

[lettuce]

Can you try another source?

I have tried a NES with RGB mod and also the Raspberry Pi, both have the same issues

You can try to attenuate or boost the sync depending on if its currently 75ohm or TTL level. Do you know which it is?

Im not sure how can i find out?

[lettuce]

Do you get this while no game system is up when navigating the menus?

This monitor doesnt have an OSD, all adjustments is pots on a breakout board

One thing worth looking into is dirty power, it's not likely to be the case but I think it's one possibility for faint horizontal rolling lines like that.

Hmmm the monitor does use odd colour coding for is wires....



Who in there right mind uses Red for ground, Black for positive and white for negative!!!

and i just used a standard power lead and connected a UK 3 pin plug to one end and then soldered barrel connectors to the Earth, Negative and Positive and then plug that into the plug coming from the monitor.....



so maybe that could be the issue as its not exactly professional done!?

[lettuce]

Any other suggestions on what might cause these issues?

[Syntax]

RGB modded NES isnt the best thing to try as a source. The sync signal has jitter which causes the top 8ish pixels to bend.

Same with an Rpi, they can cause all types of issues.

Check to see if your monitor wants TTL or attenuated sync. Is it a tri or dual sync monitor?

[lettuce]

Check to see if your monitor wants TTL or attenuated sync. Is it a tri or dual sync monitor?

Its just single sync 15khz.

How do i test to see which sync it requires?

[Josh128]

Check to see if your monitor wants TTL or attenuated sync. Is it a tri or dual sync monitor?

Its just single sync 15khz.

How do i test to see which sync it requires?

It should be on the monitor user manual/ spec sheet. It may be on a label somewhere on the unit, but unlikely. As far as your AC power plug, if you have the polarity correct theres no way thats causing the issue.

[lettuce]

Check to see if your monitor wants TTL or attenuated sync. Is it a tri or dual sync monitor?

Its just single sync 15khz.

How do i test to see which sync it requires?

It should be on the monitor user manual/ spec sheet. It may be on a label somewhere on the unit, but unlikely. As far as your AC power plug, if you have the polarity correct theres no way thats causing the issue.

Sadly it never came with a manual but the chassis is a, CH-288 chassis. I couldnt find a data sheet on it though

[lettuce]

Is there another way to work out what type of sync the monitor requires?