Re: function of multisync relay

Choreboy wrote: 
I have an NEC MS75 CRT monitor that's 3 or 4 years old.  Lately there
have been times when the horizontal sweep shrinks slightly, for less
than a second.  It can happen every couple of minutes or not happen for
several hours.

I seem to recall something similar with my last monitor before it
suddenly failed.  There's a relay that clicks when I change resolutions
or put the computer to sleep.  I suspect this relay because I do these
things much more than other computer users I know.  I have found reports
online that with other monitors this relay has been associated with
narrowing of the display.

What is the function of this relay? NEC says it closes when you go to
800x600 or higher. That seems to be true; of my five available
resolutions, there are two transitions where the relay doesn't click. However, it clicks twice when I go to or from 1024x768. 

It clicks once when the monitor is put to sleep or waked.  The screen
goes momentarily black any time I switch resolutions, whether or not the
relay clicks, so the relay doesn't cut power to the flyback.

Not understanding the function of the relay, I'm afraid it could cause a
sudden monitor failure.

This relay has an SA surrounded by a C. It is labeled VBT12TBU-5. 1/6 HP 120 VAC 5A 24VDC. 0124L2. How can I get a replacement? 

I expect different vendors use different circuits.
I remember an old monitor that used the relay to switch a capacitor
that changed the resonant frequency of the flyback circuit.
mike

--
Return address is VALID but some sites block emails
with links.  Delete this sig when replying.
..
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted 12" LCD for Compaq Armada 7770MT.
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
ht<removethis>tp://www.geocities.com/SiliconValley/Monitor/4710/

.

Relevant Pages

  • Re: function of multisync relay
    ... there are two transitions where the relay doesn't click. ... monitor's power supply as required by different resolutions and scan rates. ... If your monitor is anything like one of the NEC MultiSync 95 units I have, ...
    (sci.electronics.repair)
  • Re: function of multisync relay
    ... there are two transitions where the relay doesn't click. ... > monitor's power supply as required by different resolutions and scan rates. ... > If your monitor is anything like one of the NEC MultiSync 95 units I have, ... > then you have capacitors working on going bad in the monitor. ...
    (sci.electronics.repair)
  • Re: lighting---hacked!
    ... > You rely on ipchains/iptables to stop inappropriate packets from ... > You relay on your logging to monitor and alert you to this. ...
    (comp.os.linux.security)
  • function of multisync relay
    ... I have an NEC MS75 CRT monitor that's 3 or 4 years old. ... There's a relay that clicks when I change resolutions ... resolutions, there are two transitions where the relay doesn't click. ...
    (sci.electronics.repair)
  • Re: hvac control and ammeter
    ... the circuit breaker for the ... I'd like to monitor the current that the unit draws. ... I'm also planning on using a relay (Potter & Brumfield K10P-11D15-12, ... rated for 15A, 1/3HP, 120VAC) to control the unit. ...
    (sci.electronics.design)
Loading