Removing existing monitor...discharge?

[Sailorgoon]

I'm in the process of converting a 1995 Kaneko Great 1000 Mile Rally cab.  The existing 19" monitor is in decent shape with only minor burn in.  The colors are beginning to fade however, and I don't want to mess with a cap kit.

Since I'll be running Mame32, I am going to use an SVGA PC monitor.  In order to install a monitor however, I need to remove the existing one.

Should I attempt to discharge the monitor before removing it?  I belive that I can do it, but I don't feel completely comfortable trying.

Any input you can offer would be greatly appriciated.  Thanks for your time.

-Goon-Kun

[Dave_K.]

Yes, you should dischard the monitor before removing it.  All monitors are supposed to have a bleed off circuit to slowly drop the charge if its been off over time.  Sometimese these don't work very well in older monitors.  Better to make sure (at least 2 times) before attempting to remove it.

Use the search function above as there have been many good posts with advice.  Search google newsgoups also.  

My quick advice.  Unplug the cabinet, and monitor power.  Use a big flathead screwdriver (with long plastic insolating grip).  Get a thick gage wire (I used an appliance cord which was cut) wrap one end around the metal of the screw driver and the other end connect to the chasis/ground of the cabinet.  Using one hand (and the other hand behind your back) slide the screwdriver under the cup and make contact with the metal clip underneath.  You may here a snap.  Wait 5 minutes and do it again.  After that its safe to handle/remove the monitor.

Every time I do this, its very dissapointing as nothing ever happens (no snap).  Most monitors have a bleed off circuit to safely discharge the monitor while its off.  But better safe than sorry (especially on older monitors).

[AndyWarne]

Sorry to post again on this subject but it's a pet subject of mine as I started my career rapairing TVs and then computer CRT devices (including computer vector displays!, showing my age here)
The advice about discharging monitors is incorrect and dangerous. Monitor techs do NOT discharge CRTs before working on a monitor UNLESS they are going to do one of the following:
Replace the CRT
Replace the flyback transformer
Separate the CRT from the main board for any reason.
It is a dangerous process! It is perfectly safe to leave the charge in the CRT as it literally cannot escape unless you dive under that CRT rubber cap. The charge cannot be distributed onto the main board because it is prevented from doing so by tripler diodes sealed into the flyback molding. (otherwise the charge would quiclkly drain away through the EHT winding on the transformer). So don't do it!
BUT beware! Monitors have plenty of other nasty voltages around that ARE stored, in various capacitors on the main board. These are not discharged even if you do discharge the tube. So always leave a monitor with power off for as long as possible before handling the main board, at least 15 mins and preferably an hour or two.
Whenever I did need to replace an actual CRT tube, I used to hate discharging them, and got my fair share of whacks, when the screwdriver picks up the voltage and arcs across to your hand instead of the chassis! So dont do it just for handling the monitor intact. Think of it this way: A car mechanic does not drain the highly explosive fuel in the tank just to work on a car engine, he would do so if replacing the tank though.

[Dave_K.]

Andy, I understand there are two camps here...one side that always discharges the monitor before handling, and another thats says why bother if you aren't going near the HV parts.

I've just herd stories of people handleing tubes, and getting zapped from a charge arching from under the rubber cap.  Since this person is physically removing it from the cabinet, I'd think its safer to discharge than leave an exposed monitor laying around with a charge...but thats just my opinion.