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From: ttak@uhura.cc.rochester.edu (Timothy Takahashi)
Newsgroups: comp.sys.tandy
Subject: Re: TRS-80 monitor goes blank
Keywords: TRS-80,monitor,problems
Message-ID: <8937@ur-cc.UUCP>
Date: 13 Aug 90 14:01:48 GMT
References: <1335@svin02.info.win.tue.nl>
Reply-To: ttak@uhura.cc.rochester.edu (Timothy Takahashi)
Distribution: comp
Organization: University of Rochester
Lines: 33

In article <1335@svin02.info.win.tue.nl> wsinkees@wsinti01.info.win.tue.nl (Kees Huizing) writes:
>My father in law has an old TRS-80 Model I with a expansion box with
>extra memory, floppy connector, etc.  He still uses it, because he
>likes the computer, although connections are bad and things often fail
>several times before they work properly, etc.  Recently, a more serious
>problem occurred:  the monitor doesn't work anymore.  First, it showed
>a lot of >-signs and "encrypted" text, but he knew the questions, like
>"HOW MANY FILES?" (in Basic) and just typed the answers, and the
>program worked.  The output of the program got better and better, until
>
>1.  Do you have any idea what could be wrong?  

Sounds like a problem in the video circuitry of the keyboard/cpu unit.
A failed RAM chip in the video (a 2102 I believe). If the unit has had
a lower case modification on it, there is a lot of extra wiring on the cpu
unit. Also, the character generator chip could have fallen off! (I've seen it)

>3.  If it is the monitor, can we connect another monitor to the computer,
>for testing or replacement? 

I doubt that it is the screen that has failed.

>4.  Does it make sense to go to a Tandy shop and ask for advise, or are the
>guys there too young to know about this machine?

Try. I think there are a few Model I parts still kicking around.


>Kees Huizing - Eindhoven Univ of Techn - Dept Math & Comp Sc - The Netherlands


Tim Takahashi
ttak@uhura.cc.rochester.edu