Sony PVM (20M4"x") what dose the H & V Frequency setting do?

[wade010]

I recently purchased this model Sony PVM, it's my first high end CRT and is (was) being used for gaming, out of the box the picture was very very good, though I noticed some geometry/bending issues in the top corners and some parts of the image going off screen, I decided to play with the settings to try correct the issues, I entered the Advanced settings by pressing degauss and enter at the same time while in the main menu.

There are a bunch of changeable options to cycle through, I adjusted them all just to get an idea what they do, near the end of the list of settings was H Frequency & V Frequency I think they where called, the first time I lowered their settings the screen faded to black, I turned the monitor off and everything had reset to as it was before, in my infinite wisdom I decided to play with those settings again and see if the screen fades away, it did and then 2 seconds later I heard pop and lost power, I had managed to overheat & blow a part on the power board, a STR-M6524 IC, which I found a replacement for and am waiting to arrive in the mail.

Can anyone let me know what the purpose of those settings is, and do they require tweaking to improve picture quality in any way, or should I just leave them alone.
By lowering the values for the V & H Freq. settings I caused an IC to overheat and blowup, should that the full extent of the damage or could I have fried another component someone?
Also if anyone has this model pvm, or similar are there any setting I should look out for to improving picture quality or recommended settings to use?

A couple of other settings come to mind, Component Level: N10/SMPTE, BETA 7.5, BETA 0, which of these should be used for console video gaming? I am not sure what they do.
ACC (Auto Color Control) On/Off, is this a good or bad thing to use?

And information is appreciated & will ease the pain I feel of having just blew up my pvm within 24hrs of owning it

[trap15]

[ryu]

stay away from service menu options that don't just effect the picture in way it would be interesting for a customer (geometry, rgb gain/cut-off, pic width/height & positions).
not many people here (if any at all) have any real knowledge on these things. you'd have to ask a former sony technician.

i believethe rgb colors from the beam can age unevenly, so auto color correction might have something to do with that. i advice you just leave the option unchanged though. same for the component option.

[wade010]

That seems to be sound advice, I'll have to make sure I know exactly what the setting I am adjusting dose, because these monitors can sustain damage in a small amount of time if you "mess something up".

[22point8]

[fagin]

not many people here (if any at all) have any real knowledge on these things.

Speak for yourself.

[fagin]

wade010,
Adjusting H or V FREQ via the service menu will not blow the chassis - this has been a coincidence and has probably placed strain on a component that was on it's last legs.

[wade010]

@22point8
Thanks for the scans, very helpful.

@fagin
Thanks for the insight, this pvm was manufactured in 1999 so that makes sense, hopefully the rest of the components hold up for at least a few years, or until I get a backup pvm/bvm.
Do you know the purpose of V & H Freq.? My guess is its the flickering you see when recording a crt screen with a camera, and adjusting the settings change the V & H directions of that flicker, which should be stright up and down / left and right, which should serve a purpose, noticeable or not, or maybe its something else completely.

[fagin]

Horizontal Frequency is the frequency relating to the beam moving from the left to right and back again (number of hori lines displayed per second).

Vertical Frequency relates to number of times an entire frame is drawn per second (refresh rate).


HFREQ can be a chassis killer, if you try to drive a higher frequency than the chassis can handle. Normally you'll hear a high pitched squeal (that's the frequency) and a messed up image initially. Pushing a higher than chassis expected HFREQ won't immediately blow it - but it won't do it any good and over a period of time may cause a failure, especially on weak components.