Lingering Questions...

[FrizzleFried]

I have a PROMAX 1000C Electrohome G07 replacement chassis.   There is little information available on this chassis online...and I have a couple of lingering questions I didn't get answered on my last post,  but I feel I should find the answer to before going forward with this project.

First and foremost is the fact that I DO NOT see a grounding strap around the tube.  Is this normal?   I only have ONE SINGLE monitor for experience (a G07) and this one has nothing like the strap that goes around my G07 monitor tube about midway from the neck to the screen.  If it is normal NOT to have one,  great.   If it's supposed to have one,  can anyone point me in the direction of what i need to do to install one?

My second question is regarding the photo below.  I have circled the component on the original G07 chassis that is not hooked up to the monitor in any way.   Is this component something that this newer chassis may not need?  What is it and what does it do? 

Here's the photo:



My final question is in reference to the photo below.  I have circled what I believe is the B+ voltage pot.  Can anyone point me in the direction of where I can measure the B+ voltage in order to set this pot correctly?

Here's the photo:



Any information is GREATLY appreciated.  I should have my JPAC / AVGA here soon and will be rotating this monitor this weekend...which brings me to well..I guess a supplemental question...when I rotate,  do I rotate clockwise or counterclockwise while looking at the screen...or does it even matter?

Thanks!!

[eccs19]

I'm not an expert, but I think the item in the first picture is for degausing the monitor.  I hope someone will confirm if I'm correct or not. I'm learning also, so it's quite possible I'm wrong. 

Sorry no input on your second picture.   

[FrizzleFried]

...the white wire to the left that leads to the bundle of white tape which then leads to a red wire is attached to the degausing coil? I do believe.

Edit:

Here are some pix I just took of the monitor removed from the cabinet...

[grantspain]

you should have an earth braid on the tube linking the dag to the frame to help counter static.
is that a load resistor that was attached to the old chassis degauss,you don't need that
you should not need to adjust the b+,its factory set at the correct level
as for rotating your screen wait until you have a picture then turn the correct way

[Ken Layton]

The Promax chassis is actually a Wei-ya.

[FrizzleFried]

OK...where can one obtain an "earth braid"...or can one be made?  It it a simple case of running an exposed wire from one side of the chassis to the other ...across the tube?

...I assume I can remove the degusing resistor...being my new chasis degause works.

...I,  of course fudged with the B+ pot so factory settings have been screwed....

...I will take note of that Ken...and do a search for Wei-ya.


...and thanks!

[Rickn]

Yes, the resistor and stuff on the right are a power resistor and Thermistor for the degausser.

You don't need it discard or just leave it disconnected.

B+, - first off there is a good chance that the chassis is "hot" what this means is an isolation transformer is required (I will take another look at the picture, it is easy to tell).

In any case make sure you connect through an isolation transformer before connecting a signal or meter- or you will take out the fuse regulator and possibly more.

Having said this, still do not turn the monitor on!!

Make your own ground braid if necessary, to do this, here is a band aid.

Get some 14 Guage preferably stranded copper wire. Strip off the insulation so it is bare.

Now form a loop that will fit around 1 ear of the picture tube, say top left, the take it down and secure it to the bottom right- idealy with a spring so that it is held tight to the glass of the tube.

It must make contact to both ears and the gray area of the tube - this is the Aquadag of the picture tube and it completes the ground path of the picture tube.

Now you will need to connect an insulated wire to this Ground braid and the other end to a pin on the neckboard- it will be a molex stile pin GT- in other words it will be round in diameter (somewhat less than 1/8") and about 1/2 long.

Best way to be sure if you are not, it shoul be connected to the ground plain of the neck board.

Anyway, now we are grounded.

With Iso Transformer connected it is safe to connect signal and power up.

Now with a voltmeter- connect the ground lead to ground, the metal frame is fine.

Connect the otehr lead to the white power resistors right by trhe B+ pot, when you find one that measures between 100 and 130 volts DC -this is likely the B+.

I do not know thye B+ setting of the chassis but try 115 volts.

We do not want to set it too high , as this will cause the heater voltage of the tube to be high.

Hope this helps.

Rick Nieman

[sonetdude]

Hello,
this may be a little late,but i have one of these promax. Mind is missing a transistor to the left of the flyback Q302 gone (do you have a part number on there that would help.

thanks