sl11@prism.gatech.EDU (LIEBESKIND,SUSAN H) (06/14/91)
We've bought a few of the 400s and 400t machines, and have
noticed a bad flicker on all of the monitors that we never
had on our Apollos. I understand that these machines use
a 60 hz HP monitor (1280 color, model #98754A) and our
Apollos use a 70 hz monitor. This flicker is apparent in
color or monochrome modes, with the room lighting on and
off, and through all ranges of contrast, brightness, etc.
Can anything (short of the $10,000 upgrade per machine
suggested by our HP rep) alleviate this problem? If we
swap monitors with HP enough, could we eventually get one
with a more persistent phosphor?
We can now add migraines and eye strain to our carpal tunnel
and back problems.
If anyone can help or commiserate, please post a reply or
respond to:
Stuart McRae
Georgia Tech Research Institute
Atlanta, GA
(404) 853-0942
email: stuart@prism.gatech.edu
**********************************************
Please send all responses to stuart@prism.gatech.edu.
**********************************************
Thanks.
Susan
--
LIEBESKIND,SUSAN H
Georgia Tech Research Institute, GTRI/CSITL, Atlanta Georgia, 30332
uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!sl11
Internet: sl11@prism.gatech.edumike@bellcorebellcore.com (Mike Lukacs 21341) (06/15/91)
In article <31321@hydra.gatech.EDU>, sl11@prism.gatech.EDU (LIEBESKIND,SUSAN H) writes: |> |> We've bought a few of the 400s and 400t machines, and have |> noticed a bad flicker on all of the monitors that we never |> had on our Apollos. I understand that these machines use |> a 60 hz HP monitor (1280 color, model #98754A) and our |> Apollos use a 70 hz monitor. This flicker is apparent in |> color or monochrome modes, with the room lighting on and |> off, and through all ranges of contrast, brightness, etc. |> |> Can anything (short of the $10,000 upgrade per machine |> suggested by our HP rep) alleviate this problem? If we |> swap monitors with HP enough, could we eventually get one |> with a more persistent phosphor? |> |> We can now add migraines and eye strain to our carpal tunnel |> and back problems. |> |> If anyone can help or commiserate, please post a reply or |> respond to: |> Stuart McRae |> Georgia Tech Research Institute |> Atlanta, GA |> (404) 853-0942 |> |> email: stuart@prism.gatech.edu |> |> ********************************************** |> Please send all responses to stuart@prism.gatech.edu. |> ********************************************** |> |> Thanks. |> |> Susan |> |> We Have several of these, and although the flicker IS slightly worse than the earlier machines, only one person complained. HIS WAS A SPECIAL CASE! Because you say that your problems are unaffected by luminance level, you may have the same sort of problem. The new 1280*1024 color monitors used on the 400 series machines are made by Sony and are Trinitrons. This means that the color electron beam control shadow mask which stretches across the front of the tube just behind the phosphors is a parallel set of wires instead of a foil full of holes. This has some advantage for brighter displays and easier convergence, but has one large disadvantage; they are VERY vibration and shock sensitive. You can demonstrate this by hitting the side of the monitor with your hand while watching a screen full of text. After you hit it can see ripples go across the screen and die out over about one second. The person who complained about the flicker on his monitor was in a room near the main air return of the building, and there was a barely perceptible vibration in his floor and his desktop. this was enough to BADLY upset the trinitron monitor. Three solutions are possible, either isolate the monitors from the source of the vibration with rubber "typewriter pads" or other such mounts, or find and stop the source of the vibration, or replace the monitors with the 1280*1024 high res option monitor that was used with the DN4500 (these will work, I have tried it) that monitor was not a trinitron. HP/Apollo or Mentor or whoever your supplier/servicer is may be amenable to this last solution as a no cost swap, because the Sony monitors are actually usually more expensive than the older variety. Good Luck, Mike Lukacs DISCLAIMER: The opinions expressed | M. E. Lukacs NVC-3X-330 in the above are my own, and not | Bell Communications Research(BELLCORE) those of Bell Communications Research. | 331 Newman Springs Road By Law, BELLCORE may not have such | Red Bank, New Jersey, USA 07701-7040 opinions; and if they did, they would | not tell you for free. And I am not | (201)or(908) 758-2876 FAX: 758-0889 the person who would be giving out | official opinions anyway. And unless | mike@nyquist.bellcore.com you can PROVE that this isn't a | "First 'mike' on the UUCP network" forgery, I did not say this. | (ca.1974)