Monitor won't work with 4400/160

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2 total messages Started by Chris Bennett Tue, 17 Mar 1998 00:00

#1444

Author: Chris Bennett
Date: Tue, 17 Mar 1998 00:00

25 lines
1508 bytes

I'm trying to get a new multisync monitor to work on a powermac
4400/160, but it just goes into sleep mode as soon as the mac starts up.
If you force it to wake up (by pressing a button on the front panel) it
cycles on and off, with no picture on the screen.

Now, this monitor *does* work on an old performa 475 and switches
resolution with no problems. Similarly, the 4400 does work with the old
fixed frequency 14" monitor. It's just the combination of 4400 and new
monitor that doesn't work.

The mac adaptor supplied (it's got a vga connector) does not have any
switches and is marked 640x480/832x624/1024x768. These modes work with
the 475.

I have been in touch with the shop it came from, but they haven't yet
been able to sort it out. I've also spent 2 hours doing web/usenet
searches with no success, although there are similar problems which seem
to have cropped up with other people, especially with Sony monitors and
Tanzania motherboards :-(  (not necessarily together).

Any ideas ? apart from zapping PRAM and booting from CD, neither of
which help.

Chris.

Re: Monitor won't work with 4400/160

#1451

Author: andy the pugh
Date: Wed, 18 Mar 1998 00:00

38 lines
2260 bytes

In article <1d61r0w.8icmhy1dsbgkoN@lunedale.demon.co.uk>, the moving finger 
of chris@lunedale.demon.co.uk wrote...
>
>I'm trying to get a new multisync monitor to work on a powermac
>4400/160, but it just goes into sleep mode as soon as the mac starts up.
>If you force it to wake up (by pressing a button on the front panel) it
>cycles on and off, with no picture on the screen.
>

>I have been in touch with the shop it came from, but they haven't yet
>been able to sort it out. I've also spent 2 hours doing web/usenet
>searches with no success, although there are similar problems which seem
>to have cropped up with other people, especially with Sony monitors and
>Tanzania motherboards 

The problem may well be that the Tanzania on-board video doesn't do 
composite synch above 640x480.[1], and the adaptor probably just 
takes CSYNCH through and ignores H and V synch, merely emulating the 
17" multiscan monitor sense codes. 

I had a really rather wierd time getting an old fixed frequency workstation 
monitor working with my 4400[2], but finally cracked it by using the 'Mac 
Composite Adaptor' from Griffin (http://www.nashville.net/~griffin). They 
told me what I needed promptly and put me in touch with a UK distributor. 
The adaptor takes the Mac H and V synch signals and makes a CSYNCH. It cost 
about 20 quid.

[1] Not, as it happens, the whole truth. If you boot with the 14" monitor 
then switch to a higher resolution using the 'Multi Resolutions' contol 
strip module(highly recommended for this sort of faffing about) , then plug 
the bigger monitor in to the mac you may find it happily cntinues to do 
CSYNCH at the higher resolution. Not a good long term solution though.

[2] And all dur to be repeated now I have pulled a 20" Hitachi out of the 
skip. 

ap

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