On Sun, 3 Dec 1995, Paul Boven wrote:

> Date: Sun, 3 Dec 95 23:58:06 
> From: Paul Boven <e.p.boven@student.utwente.nl>
> To: tsunami@imsa.edu
> Cc: port-sun3@NetBSD.ORG
> Subject: Re: My 3/60 keyboard (and monitor)
> 
> Hi tsunami,
>  
> > Ok..it works now.  I took the fuse out of the socket at the front of
> > the motherboard (away from all the connectors..) and put it in the socket
> > at the keyboard port (is this a bad thing to do?) and it works now.
> 
> uhh... I'd guess something else is without power now, and that's not good of
> course. If it won't netboot, you found the ethernet-fuse :)
> 
> > But, now (this happened before too, but I was hoping it would go away), 
> > the monitor kind of phases out, like an old tv.  I think it might be
> > aliens.  Any better suggestions?  It seems to be the framebuffer rather
> > than the monitor (turning the monitor off for a bit and then back on
> > doesn't do anything, but turning the whole system off for a while then back
> > on fixes it).  Hitting the monitor has soem effect (it causes it to
> > display different patterns of stripes).
> 
> My 19" monochrome has the same problem. It is, in my situation, *only* a monitor
> problem. What has happend is that in it's long and usefull life, the sync-circuits
> in the monitor got a bit misaligned, probably by ageing. I have exactly the same
> symptoms, but they go away as the monitor heats up. 
> This hasn't been a problem so far, as starting X would take longer, but with 
> the new SCSI-DMA (kudos, boys!) my Sun now boots faster than it's monitor does.
> 
> Remedy: First, DON'T hit the monitor. Hitting electronics is never a good idea, 
> even though it sometimes seems to help short-term. Worst case, you'll break the
> glowing filament in the cathode of the tube, and your monitor will go from mono-
> chrome to zerochrome. The dreaded eternal screenblank. 
> By the way, why are you hitting the monitor when you're so sure it's a 
> framebuffer problem? :)
> 
> What you have to do, is to readjust the sync-circuitry in the monitor. It's best
> to have someone with some experience in electronics (TVs) do this. As this exposes
> some dangerous high voltages, don't try this on your own. Have at least someone
> stand by to disconnect mains to the monitor, and *after* that help you.
> 
> (Yours truly once almost died when fixing someones colour TV, because only for 
> a small moment he was caught off-guard, and zapped by part of the HV. I was
> dazed for a few minutes, lying on the ground, alone. Had half a bottle of
> Coca-Cola to get a back to life a bit, then I realized how close it had been,
> and downed the other half. About 15 minutes after that, someone happened to show
> up. I *never* do HV electronics alone anymore.)
> 
> When you open the monitor, and remove the shielding metal, you'll find a row of
> labeled potentiometers that control the operating parameters of the syncs. You
> can adjust height, width, offsets, and of course the frequency. It is the latter
> that has to be adjusted. Only do adjustments when it's off, and even then with
> a fully insulated screwdriver, because of possible remaining high-voltage in 
> parts of the circuitry. 
> 
> Before reassembling, turn everything off for a long while, so it can get back
> to room-temperature, and see how it behaves on power-up. I should have done that,
> now I need to readjust it again.
>  
> Succes. 
> 
> Paul.
> 
> 
> 
Yes, the anode on the tube has 28.8 kilo volts.  Enough to turn anyone to 
ashes from the bone out.  It used to take my monitor a long time to come
up until I upgraded my rom revision.  The latest rom revision for 3/60 is 
3.0.  I have it, and it is software writable.  Let me know if anyone 
wants it.  I thought of attaching it to this letter, but it may not be
the responsible thing to do.
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     .--.  __  .---------     Rahim Azizarab     
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