| Author |
Message |
mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
|
| Posted: Sun Jul 18, 2010 6:24 pm Post subject: Marquee HVPS daughter board failure.. |
|
|
I've been going over a bunch of my HVPS the past few days seeing which ones worked and which did not because I've just had some here and there over the years.
In checking them out I found three of them to have problems on the daughter board (control PWB) inside the HVPS.
With the three defective boards removed from the HVPS. I put each of them in a working HVPS to further isolate and confirm they had a problem.
One would not allow the HVPV to fire up. The other two produced a problem one way or the other on the RED G2.
I have more HVPS to check out, but for now I'm stoked that for the first time I'm finding a problem on one of these boards.
I also found out that the G2 control for the G2 lines on the HVPS is on this same daughter board.
But the biggest thing I've noticed is that two of these boards show signs of glycol leaking onto them.
So before you trash that supply, make sure you check that daughter board...
Uploaded with ImageShack.us
|
|
| Back to top |
|
 |
Tim in Phoenix
Joined: 21 Oct 2006
Posts: 4409
Location: Phoenix
|
| Posted: Sun Jul 18, 2010 6:29 pm Post subject: |
|
|
Guys!
I fixed a board that exhibited flashing in the picture; the trick was to pull and clean each socketed chip and chip socket with solvent.
.
|
|
| Back to top |
|
|
antorsae
Joined: 16 Jul 2006
Posts: 297
|
| Posted: Sun Jul 18, 2010 7:53 pm Post subject: |
|
|
Is it a good two swap daughter board across HVPSs?
I am asking b/c if I recall correctly the potted trim was related to max HV current and calibrated with special equipment for each HVPS.... if you swap the daughter board you could change the effective max HV current - right?
|
|
| Back to top |
|
|
mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
|
| Posted: Sun Jul 18, 2010 8:55 pm Post subject: |
|
|
| antorsae wrote: | Is it a good two swap daughter board across HVPSs?
I am asking b/c if I recall correctly the potted trim was related to max HV current and calibrated with special equipment for each HVPS.... if you swap the daughter board you could change the effective max HV current - right? |
Good points!
I have a Fluke high voltage probe that I'll be looking at this when I get back to it. My probe has the lead from a CRT soldered onto it, so it connects directly to the splitter.
I plane to finish going over my HVPS's and when I do get things in order, I'll be upgrading the resistors and making a few other changes. I'll also be making sure the HV voltage is calibrated to the 34.9kv listed on the supply.
One thing I do know for sure is that it's very important to have that voltage as close as possible to the spec.
The first one I upgrade and calibrate I'm sending to Tim.
Here you go - get you one of these:
http://www.transcat.com/catalog/productdetail.aspx?itemnum=80K-40
You'll need a digital fluke meter to plug it into, but with a high end setup like yours, the cost for the probe would be worth it.
|
|
| Back to top |
|
|
JustGreg
Joined: 07 Mar 2006
Posts: 3098
Location: Kenosha, WI
|
| Posted: Mon Jul 19, 2010 5:31 am Post subject: |
|
|
Dayuuummmm! It would be WAY cheaper to ship it to you, Curt or Tim and pay you to calibrate it. The seals on the pots of both
my HVPS's look untouched but it does make me wonder how much they've drifted.
Are you going to post what you changed Mike? I know you guys don't want the casual electronics hobbyist in the HVPS for obvious safety reasons...perhaps if you aren't selling a re-cal service you could PM what you've done? Just a thought.
I'd definately pay to have mine calibrated regardless.
_________________
Greg
"Is it ignorance or apathy? Hey, I don't know and I don't care!" --Jimmy Buffett
|
|
| Back to top |
|
|
mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
|
| Posted: Mon Jul 19, 2010 8:10 am Post subject: |
|
|
I think Curt has a probe and could do this. And whatever I find out looking over the daughter board failures I'll pass on to him. Because you're right about us not wanting the hobbyist poking around in the HVPS for obvious safety reasons.
One thing for sure, if the HV is off, it will effect the overall performance of the projector. That can be found out quite easily by simply putting an earlier version 34kv HVPS in a 9500 and cranking up the brightness.
Two things happens with a 34kv in a 9500 - The projector will prematurely bloom when the contrast is increased. And the focus would drop out at higher scan rates with increased contrast.
The test to confirm this would be the SMPTE bandwidth test pattern at 1080P.
hard to believe the difference noticed from just that additional 900 volts on the later model HVPS...
Now what if your HVPS is not at spec (34.9KV)...hmm
Looking into this and troubleshooting the problem I don't mind doing. Repairing, upgrading and calibrating these supplies is something I'd rather see done by someone with Curt's qualifications. Plus, I'm not aways around to do this kind of stuff anymore.
Hey, I found another HVPS to not fire up because of a problem on a daughter board..
|
|
| Back to top |
|
|
|
|
