Model 4 monitor help

[bjones]

hi all.. is there by chance a repair guide for the typical monitor found in a model 3/4? I have one that the contrast is just really weak. The brightness is really good, if I turn it all the way up the screen turns nice bright white, but when I turn it down to see text on the screen the contrast dial has to be all the way up to see much of anything. Not really certain what the cause is of that, or what to look at replacing. My best guess is a cap somewhere, but which one i dunno

Thanks!
/b

 

[vwestlife]

Not sure if this will help, but here is a tutorial on how to replace the picture tube in a Model III or 4:

 

[TRS-Ian]

That's my video but it has no info that would assist with the problem of low picture intensity that bjones is having.

As a matter of fact I had the exact same problem with a 4P I recieved recently, and my quick repair was to just install a good used video board from another computer. The observation is a nice sharp raster but very dim text.

If anyone works out which component is failed I'd be very keen to know.

Ian.