1084P out of focus

[brett71]

Hi, guys,

I recently bought a used 1084P. The monitor is fully operational, however, the screen is very blurry. The previous owner was an electronics technician who cobbled it together from 3 non-working 1084P's, but he says he couldn't get it focused any better, and the blurriness is due to age.

I was just curious if there is a replaceable part which could correct this, or is there nothing further that can be done to improve the picture quality?

Thanks!

[Mr B]

In theory adjusting the focus & video circuits could / should fix most of the problem, fixing the degauss could possibly take care of whats left to fix. Other then that the phosphorus coating on the inside of the tube might have aged beyond what it can take...

I think all the service instructions are here if you decide to try. I'm not certain tho, as i wouldn't be able to...

Good luck.

[Jope]

Curious.. Was a new flyback transformer fitted when refurbishing it (perhaps the flyback isn't supplying sufficient focus voltage to the neck board)? Are all voltages (especially B+) on the chassis ok? If the yoke is not the original one that shipped with the tube, perhaps it hasn't been converged properly and the repairman left the focus a bit off?

Unfortunately there isn't a lot of experience based 1084 debugging knowledge floating around, but the service manuals are available as PDF. Hope you have a scope and some knowledge about working with CRT monitors so that you don't kill yourself by poking your finger in the wrong place.

But like I mentioned in some other thread, this is one of those things that if you need to ask, you shouldn't attempt it yourself.. It's not black magic, but since there are lethal voltages involved, no-one wants to take responsibility.

The info is out there, especially video arcade related forums have a lot of monitor talk. That knowledge, coupled with the correct service manual and the right measurement equipment (a good multimeter, an oscilloscope) put together will allow you to learn how to repair your 1084.

[brett71]

As I said, the previous owner cobbled it together from 3 non-working 1084P's: a picture tube from one, flyback from another, main PCB from another. It's quite possible the flyback isn't providing the voltage, but I have no electronics experience, so I have not checked on it.

Due to my severe lack of knowledge, I don't plan on trying to fix this thing myself. I know the dangers of working with CRT's, and would prefer not to electrocute myself.

I was mainly curious to find out if there was any hope at getting the monitor focused properly and if there were any replacement parts available which might help, and if so, which ones I might need.

Thanks for the advice so far, though!