CurtPalme.com Home Theater Forum

[Curt Palme]

So I'm working on a standard Barco 1208 power supply. WOrked on 100s before, literally.

Typical problem... or so I think. Blown parts, chip, etc. Replace them all, the set now powers up, but with a scan fail. No big deal, methinks, I go and tweak the H width pot, that seems to be a bit more finicky on 1208s than other Barcos. It has to be set within 1/8 turn or so usually, otherwise you'll get a scanfail.

POOF! Fuse blows, all the same parts that I just put in blow again. I check... there's a part that has NEVER failed before on any Barco SMPS that I've worked on which caused all the parts I put in to blow again.

1/2 hour later, I have all new parts in again. Turn set on. Dead.

Turns out that brand new chip that I put into the set has a dead short at its output. Again, in the dozens of SMPS chips I've changed (probably high dozens!), I've never had one bad one that was brand new. Good thing I had one more, I need to order more, that was my last one.

SMPS is working now, but what a long time to get to a working supply.

Oh, and in the process, I scrapped one of my 1208 test chassis. It was acting up for a while, but now I can't get the convergence to work at all, and I don't need two 1208 test chassis here. It's getting stripped.. NOW!

[Curt Palme]

So I'm working on a standard Barco 1208 power supply. WOrked on 100s before, literally.

Typical problem... or so I think. Blown parts, chip, etc. Replace them all, the set now powers up, but with a scan fail. No big deal, methinks, I go and tweak the H width pot, that seems to be a bit more finicky on 1208s than other Barcos. It has to be set within 1/8 turn or so usually, otherwise you'll get a scanfail.

POOF! Fuse blows, all the same parts that I just put in blow again. I check... there's a part that has NEVER failed before on any Barco SMPS that I've worked on which caused all the parts I put in to blow again.

1/2 hour later, I have all new parts in again. Turn set on. Dead.

Turns out that brand new chip that I put into the set has a dead short at its output. Again, in the dozens of SMPS chips I've changed (probably high dozens!), I've never had one bad one that was brand new. Good thing I had one more, I need to order more, that was my last one.

SMPS is working now, but what a long time to get to a working supply.

Oh, and in the process, I scrapped one of my 1208 test chassis. It was acting up for a while, but now I can't get the convergence to work at all, and I don't need two 1208 test chassis here. It's getting stripped.. NOW!

[macgyver655]

I think you were just in the mood to blow something up today. Come on now Curt, admit it. It's fun sometimes......

Maybe I'll go jam a screwdriver in a plasma and see what smokes up first.......