CurtPalme.com Home Theater Forum

[Curt Palme]

So.. the guilty shall remain nameless..

I sold a Barco 909 about 9 months ago for megabucks, this was one of the first 909s I'd had in, back when even less people had them Sold it for top $$.

A couple of months ago the customer called, saying that the set had died. I was a bit freaked, as I didn't have a spare test chassis, so I told him to send me 4 boards out of the set, the three power supplies and the H board. The exact problem was that the set 'chirped', usually indicating a power supply overload or short somewhere, so I figured those 4 boards would cover it.

Customer sends the boards in, I open the box, and there in this very thin box were three heavy boards, one lighter board, no bubble wrap between them, and all the module locking tab assemblies had snapped off the modules. Those are pretty hard to break, I wasn't impressed.

So, while I took a quick peek at the boards, I had to wait for a test chassis to show up, so the boards sat here for a bit. And a bit more.

Finally this week I got a test chassis in, so I dove into the boards. First off was the AC input board. It caused the working SMPS in my set to chirp. Good news, the problem is only on one board. I found three PC board traces that had broken due to the board flexing. Anyone that's seen the high quality fibreglass boards that Barco uses knows it takes a helluvan impact to fracture those boards. A few minutes later, that board is working. No defective components.

Next up, put the SMPS into the set. It chirps. WTF? OK, since the AC input board had physical damage, I figured maybe it was OK until it shipped, so I dive into the SMPS. I find a leaky surgistor, that diode I posted about yesterday. Pull out diode, run set for a couple of seconds, everything works. Put board aside, put original SMPS back in, test G2 board. It checks OK.

Then I put in the H deflection board. I get a scan fail LED on, no picture. Again... WTF? I spend some time printing and pasting together the large schematic of the H output board, and find that it has no drive to the H output tranistors. I look for physical damage, figuring I'd find something bent or snapped off the board. No burnt traces, no cracked PC board, nuffin.

Keep in mind that I'm learning the chassis as I'm going, as this is my first or second foray into a bad 909 board(s). So I keep tracing., keep running down to the computer to print out more schematics, etc.

Finally about 1/2 hour ago as I'm REALLY frustrated, I finally realize that right next to the ripped off module locking piece is a zener diode, right up against the plastic rail. Only on this board, the zener is missing. I check the original H board from the set, the zener is there. Grab magnifying glass, check where the zener is, it really doesn't look like it got ripped off the board, but hey, it's an SMT device, little pressure is needed to rip the part off the board, and maybe, just maybe, the solder joints COULD have bad an SMT device taken off them without showing signs of damage.

I go tack in a regular size zener, away the set goes! Whew!

So. Pack your damn boards up well as per the instructions on the main site! Throwing expensive boards that are currently not really available on the used market is a really BAD idea. Luckily I was able to save these.. and learn craploads about Barco power supplies and H boards..

[Curt Palme]

So.. the guilty shall remain nameless..

I sold a Barco 909 about 9 months ago for megabucks, this was one of the first 909s I'd had in, back when even less people had them Sold it for top $$.

A couple of months ago the customer called, saying that the set had died. I was a bit freaked, as I didn't have a spare test chassis, so I told him to send me 4 boards out of the set, the three power supplies and the H board. The exact problem was that the set 'chirped', usually indicating a power supply overload or short somewhere, so I figured those 4 boards would cover it.

Customer sends the boards in, I open the box, and there in this very thin box were three heavy boards, one lighter board, no bubble wrap between them, and all the module locking tab assemblies had snapped off the modules. Those are pretty hard to break, I wasn't impressed.

So, while I took a quick peek at the boards, I had to wait for a test chassis to show up, so the boards sat here for a bit. And a bit more.

Finally this week I got a test chassis in, so I dove into the boards. First off was the AC input board. It caused the working SMPS in my set to chirp. Good news, the problem is only on one board. I found three PC board traces that had broken due to the board flexing. Anyone that's seen the high quality fibreglass boards that Barco uses knows it takes a helluvan impact to fracture those boards. A few minutes later, that board is working. No defective components.

Next up, put the SMPS into the set. It chirps. WTF? OK, since the AC input board had physical damage, I figured maybe it was OK until it shipped, so I dive into the SMPS. I find a leaky surgistor, that diode I posted about yesterday. Pull out diode, run set for a couple of seconds, everything works. Put board aside, put original SMPS back in, test G2 board. It checks OK.

Then I put in the H deflection board. I get a scan fail LED on, no picture. Again... WTF? I spend some time printing and pasting together the large schematic of the H output board, and find that it has no drive to the H output tranistors. I look for physical damage, figuring I'd find something bent or snapped off the board. No burnt traces, no cracked PC board, nuffin.

Keep in mind that I'm learning the chassis as I'm going, as this is my first or second foray into a bad 909 board(s). So I keep tracing., keep running down to the computer to print out more schematics, etc.

Finally about 1/2 hour ago as I'm REALLY frustrated, I finally realize that right next to the ripped off module locking piece is a zener diode, right up against the plastic rail. Only on this board, the zener is missing. I check the original H board from the set, the zener is there. Grab magnifying glass, check where the zener is, it really doesn't look like it got ripped off the board, but hey, it's an SMT device, little pressure is needed to rip the part off the board, and maybe, just maybe, the solder joints COULD have bad an SMT device taken off them without showing signs of damage.

I go tack in a regular size zener, away the set goes! Whew!

So. Pack your damn boards up well as per the instructions on the main site! Throwing expensive boards that are currently not really available on the used market is a really BAD idea. Luckily I was able to save these.. and learn craploads about Barco power supplies and H boards..

[stefuel]

OK, I can't stand it any more. At this time, 118 people have read this thread. Who's gonna own up to shipping these things in a blender?

[Curt Palme]

He's probably not a forum member.

[Curt Palme]

He's probably not a forum member.

[stefuel]

"probably not"
That's kind'a like being almost pregnant.

[km987654]

This guy has too much money. After your repairs does the projector work or did you only reapir what was damaged in transit??

[Curt Palme]

I'm just waiting for the surge protector for the power supply to show up, but all the boards he sent now work.

[Curt Palme]

I'm just waiting for the surge protector for the power supply to show up, but all the boards he sent now work.