DEC VR260 service docs / common failure modes?

[Douglas Taylor]

That's a very interesting comment, got me to thinking.  The VR150 was 
connected to a working Vax Station 3100 with the proper DEC cable and I 
observed the non-working behavior.  However, the color RGB output from 
the VS3100 works just fine, I boot the machine into VMS and runs just OK 
(but using a different monitor and video cable).

In the VS3100, at least the one I have M78, I think the monochrome video 
output is separate from the RGB outputs.  I wonder if that part of the 
video circuit is not working correctly?

I understand your comment about the rate, the VR150 is a non-standard 
video refresh rate.  I think it is hard wired just for the DEC video output.

Doug

On 8/10/2020 1:37 PM, Bill Degnan via cctalk wrote:
> One comment...if you don't have the correct cable and a system that is set
> for the correct refresh rate, it may appear that the monitor does not
> work.  Be sure you have compatible equipment.  This was a specialized
> display.
> Bill
>
> On Mon, Aug 10, 2020 at 1:19 PM Douglas Taylor via cctalk <
> cctalk at classiccmp.org> wrote:
>
>> Josh;
>>
>> I have a DEC VR150 that is nearly functional; shows full screen but the
>> H/V are not in any sync at all.  Would love to use it with a VaxStation
>> 3100.
>>
>> Opened it up and found it quite a complicated monitor, not like a simple
>> PC monochrome monitor.
>>
>> Purchased a microfiche manual off ebay, but haven't been able to view it
>> yet.
>>
>> Eager to hear how you do with your larger monitor.
>>
>> Doug
>>
>> On 8/9/2020 3:10 AM, Josh Dersch via cctech wrote:
>>> Hi all --
>>>
>>> Picked up a non-functional but otherwise nice looking DEC VR260 (19" b&w
>>> monitor) on the cheap, hoping to use it with my VAXstation 2000.  From
>> what
>>> I've read, these were never the most reliable displays.  Curious if
>> anyone
>>> has any information on common failure modes, or has service docs
>> squirreled
>>> away somewhere.  I've at least found schematics, so I have something to
>> go
>>> on, but it's not exactly the most straightforward design I've poked at.
>>>
>>> Right now when powered up I hear a repeated low hum from the transformer
>>> followed by a soft ticking noise so I'm guessing I've got power supply
>>> issues at the very least.  Unsure what I should expect the monitor to do
>> if
>>> it's not being fed a valid video signal (I haven't yet tried to hook the
>>> VS2000 up to it) -- whether it'll go into free-running mode or do mostly
>>> nothing until it has something to sync to...
>>>
>>> Thanks as always,
>>> Josh
>>
>>