Anyone know how to repair the vertical collapse on an Apple III monitor?

[NoleOne]

Rescued an Apple III with monitor by the road a while back.

 

After cleaning it up, I turned it on and everything worked! I purchased some old diskettes and some hardware to make new boot disks, etc. to tinker around with it. Unfortunately, I booted up not too long ago and the monitor only displayed a green line. I did some digging and it sounds like the "vertical collapse" is not working.

 

Any help is appreciated.

 

In the meantime, does anyone know what I can use as an alternative monitor? I have a couple of Commodore 1702's and a 1902A.

 

Thanks in advance.

Edited April 17, 2017 by NoleOne

[bpatte02]

It might be best if you replaced it. Monitors like CRT tv's hold a great deal of high voltage and if not worked on properly can cause injury and even death. If you don't have experience in soldering and General electronic work I would hesitate to suggest working on it. It does however sound like something that controls the vertical portion of the monitor has gone bad. It unfortunately could be a number of things which requires a bit of trial and error. My suggestion is if you are dead set on repairing it you should find a schematic and learn about the different components. From there you can figure out what you might think the issue is.

 

I can't say What a good replacement is for that particular monitor, but if the signal is component you should be able to use anything that has component even a tv. Again I'm not an expert on the Apple III but you could try a tv and see if it works

Edited April 17, 2017 by bpatte02

[Keatah]

What was the name of the road you found it on?

[Arnuphis]

Could be dry solder joints on the board at the back of the tube, dead capacitor/vertical IC or something as simple as adjusting the screen voltage knob on the flyback transformer. In any case there are some big volts inside so if you don't feel comfortable discharging them best to leave it alone. Not sure on the video output on an Apple III but my apple II works fine with a Commodore 1084 monitor.

Edited April 17, 2017 by Arnuphis

[NoleOne]

Thanks for the advice.

 

It turns out that it is not the monitor. I plugged the Apple III into a commodore monitor and got scrambled characters on the screen just like the Apple III monitor. The computer turns on and everything and tries to boot up, but the output on the screen is scrambled. It seems like it is working otherwise, but there is something wrong with the video output on the computer itself.

 

Any ideas?

Edited April 18, 2017 by NoleOne

[MarkO]

<< SNIP >>

Any help is appreciated.

 

In the meantime, does anyone know what I can use as an alternative monitor? I have a couple of Commodore 1702's and a 1902A.

 

Thanks in advance.

 

There are Two People that you need to know about:

 

John Keoni Morris on Facebook

and

SpeedyG on Applefritter

 

 

John Keoni Morris does lots of Repair Work..

 

SpeedyG's Web Site, Apple II Box has lots of Technical Info..

 

 

 

The Commodore 1702 should work fine...

 

 

MarkO

Edited April 20, 2017 by MarkO

[NoleOne]

There are Two People that you need to know about:

 

John Keoni Morris on Facebook

and

SpeedyG on Applefritter

 

 

John Keoni Morris does lots of Repair Work..

 

SpeedyG's Web Site, Apple II Box has lots of Technical Info..

 

 

 

The Commodore 1702 should work fine...

 

 

MarkO

 

Thank you for the information. Appreciate it.

[MarkO]

 

Thank you for the information. Appreciate it.

 

 

I should amend, that on the C1702, 40 Column will be fine as well as Video Games.. 80 Column will be hard to read on it..

 

The Apple Monitor /// or Apple Color Monitor ][e will do 80 Columns just fine..

 

 

MarkO