Jen Shinn Model 329 High Pitch "Whine"

[MK3FAN]

Ok, as I said in the title, I have a Jen Shinn Chassis that's only about 4 months old. It worked fine until I took it out of one of my cabs to replace the monitor. Something else came up and it sat in the garage for a couple months. Then I went to test it tonight, and all it does is make a high pitch "whine". It does this whether it's hooked up to the monitor or not. There is no neck glow or activity on the monitor of any kind. Anyone know anything about this?

[qrz]

if this chassis uses a Switch Mode Power Supply ( SMPS), there may be a short on a secondary in the supply .
possibly a diode/cap in the supply itself , or in the adjoining circuitry ( vert out ic/ HOT common faults ).
grab the vom and search....

qrz

[MK3FAN]

if this chassis uses a Switch Mode Power Supply ( SMPS), there may be a short on a secondary in the supply .
possibly a diode/cap in the supply itself , or in the adjoining circuitry ( vert out ic/ HOT common faults ).
grab the vom and search....

qrz

Sorry. Not familiar with the term "vom." You'll have to forgive me.

[sarge]

VOM=Volt Ohm Meter

Are you sure there is no neck glow?  Many chassis make a high pitch whine if their not receiving the sync signal they are expecting.  Not very familiar with your make/model though.

[Ken Layton]

Only four months old? Might be under warranty. Contact whoever you bought it from.

[MK3FAN]

VOM=Volt Ohm Meter

Are you sure there is no neck glow?  Many chassis make a high pitch whine if their not receiving the sync signal they are expecting.  Not very familiar with your make/model though.

Ah, I just refer to it as an Ohmmeter. I am positive there is no neck glow. The tube didn't even charge up when I turned the chassis on. Here is a picture of the chassis on the tube it used to work on....



When I tested it and found it not to be working, I used another chassis I had and verified that the tube was good. So, there is definitely something wrong with this chassis. No problem though. We'll figure it out.

[MK3FAN]

Got it working again. Turns out it was a sync wire that was cut down the line that I didn't know about. I ran a new wire, and it works now. Only thing is, the picture is kinda "dull." I adjusted the standards like screen, and remote controls, but still seems "dull." It's not the tube, cuz when I take this chassis out and put a WG k7000 on it, it looks great! The Jen Shinn chassis is practically brand new. I don't know if there's anything I can do about it, just seems kinda strange. All my other Jen Shinn chassis's have a fantastic picture. It's something with this particular one.

[Ken Layton]

You tried adjusting the neckboard pots?

[MK3FAN]

You tried adjusting the neckboard pots?

Yes. They all work respectively, but does not add to the 'crispness' of the picture. This same kinda thing happened on one of my other k7000's a while back and it turned out to be a flyback. After I changed it out, the picture was much sharper and much crisper. I think it may be a faulty/not-all-it-can-be flyback.

[qrz]

ok, ur whine was a free running h osc  ( no sync) .hadn'd thought of that       surprised was nothing on screen.

i doubt the fly is ur problem . would suggest checking the video input lines and then
do an alignment .

with a color bar pattern ( many times on game test)  on screen .
turn brightness and contrast to min.
adjust screen ctl ( bottom pot on fly) up/dwn until a very faint image is seen .
then adjust contrast and brightness to desired levels .

white balance  ( greyscale) adjustments may be performed at this point if needed

qrz

[MK3FAN]

Thanks qrz. I'll try that.