CurtPalme.com Home Theater Forum

[Corleone88]

Hi,

On a Barco 1209s (or more generally), what are the symptoms of a quad board showing signs of weakness before complete failure?
Thanks

[jaredjaric]

I think the symptoms would be the same with most of the barco crt models.

On my 909s, i remember,
The symptom was blooming video or out of focus video , like boosting the contrast too high.

[Corleone88]

Thanks jaredjaric.
I remembered something about a permanent noise (buzzing) and a suddent black picture (but projector keeps running though). But I am not sure, that is why I am asking

[jaredjaric]

The buzzing usually or in my experience was the quad leaking out hVs or arcing.
This is what Curt was saying about the potting compound failing and becoming conductive from the carbon dust,
look for arcing quad body in the dark, and try to locate it.
Usually arcing is near the two bolts ,these bolts also holds the transformer inside the quad,
if you can see carbon buildups.
Try to clean it up and insulate it with rtv silicone,it will last a bit longer.

[Dancrt]

From my failed ones you watch a movie and after about a hour picture goes black
Tubes off and in restart does same after 10 mins if you let alone for ages might work again
For 30 min but in the error log shows HV failed.
Another one I had would flicker blue and werid scrolling screens then picture off...
Also when my convergence board failed it did simalar but no hv fail code but had a bad smell as something shorted

[Corleone88]

[Curt Palme]

Shorted quads can smoke the transistor on the EHT board, usually instantly, which then blows the fuse.
Most quads will trigger the EHT shutdown light(s) on the EHT board.

Bad splitters can change the focus of the set over 30 minutes or so, sometimes longer. Arcing splitters internally can also make the picture shake.

That's why I've been selling the quads and splitters as tested pairs in the last year, and I run them for 24 hours in a set here before shipping.

I am now totally out of 808 and 909 quads, but the 1208/1209/1209s quads will work, if you use a longer mounting bolt, and a nut, to offset the quad from the chassis by 3/4 of a cm or so. That allows the side mounted HV wires to clear the chassis so that they do not get pinched. Unless someone else has 808/909 quads out there, I'm down to about 20 of the 1209 style.

[Curt Palme]

Shorted quads can smoke the transistor on the EHT board, usually instantly, which then blows the fuse.
Most quads will trigger the EHT shutdown light(s) on the EHT board.

Bad splitters can change the focus of the set over 30 minutes or so, sometimes longer. Arcing splitters internally can also make the picture shake.

That's why I've been selling the quads and splitters as tested pairs in the last year, and I run them for 24 hours in a set here before shipping.

I am now totally out of 808 and 909 quads, but the 1208/1209/1209s quads will work, if you use a longer mounting bolt, and a nut, to offset the quad from the chassis by 3/4 of a cm or so. That allows the side mounted HV wires to clear the chassis so that they do not get pinched. Unless someone else has 808/909 quads out there, I'm down to about 20 of the 1209 style.

[AnalogRocks]

Didn't someone try to make these a few years back?

[AnalogRocks]

Didn't someone try to make these a few years back?