substitute tube for DEC VR201?

Tony Duell ard at p850ug1.demon.co.uk
Mon Sep 15 16:03:28 CDT 2008


> 
> On Saturday (09/13/2008 at 08:52PM +0100), Tony Duell wrote:
> > > I'm also toying with the idea of fitting an LCD into a VR201 cabinet
> > > and although it wouldn't be authentic, it would sure make the system
> > > more useable.
> > 
> > I am curious as to why an LCD in the VR201 cabinet is more useable than 
> > the CRT. I can't see much difference in useability (but would much rather 
> > have to repair a CRT_based monitor than an LCD-based one).
> 
> Well, if I can't find a tube to replace it... then I'd consider an LCD.

Do you really have no old 12" monchrome portable TVs/monitors around? I 
am sure you could find a CRT that would work.

> Repair of the unit after the LCD was swapped in would be by replacing
> the entire LCD subsystem.  But-- I'm betting that if the LCD survives

Assuming you could get one.... I can see you having the same problem as 
finding a replacement CRT now...

> the first few hours of life, it will then probably outlive me and it
> becomes the next guy's problem to repair it :-)

Well, in all my classic computers I've had one CRT fail. That was in a 
Volker-Craig terminal and amazinging the weld between the cathode and its 
base pin factured, so there was no cathode current (no, I don't mean 
heater/filament here). I remember raiding a CRT from another old monitor, 
popping it in and having no problems.

I've had 2 or 3 LCD panels fail, due to the ceals between the 2 class 
plates failing and the liquid crystal itself leaking out. The panel turns 
black from one corner/edge since without the LC material, the plane of 
polarization of the light is no longer twisted, so the 2 external crossed 
polarisers son't transmit much.

In terms of the driver circuitry, I don't think I've had an LCD driver 
chip fail. Of course I've had CRT drivers fail, but normallly an 
easy-to-get component, like a transistor, dies.

> I think what I really need to do is just come to terms with looking
> through the fog.  The monitor works fine otherwise--  nice and bright
> and no burn-in so the whole issue is strictly cosmetic.

I've never tried to remove and re-bond a faceplate, but I've heard others 
have mamanged it. 

-tony



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