CurtPalme.com Home Theater Forum

HK-Steve · Posted: Fri Jun 11, 2010 1:16 pm Post subject: Marquee HVPS Fuse exploded

Hey Everyone,
I just picked up a friends HVPS because he turned on his 9500 Ultra, then heard this very loud "POP"
Projector would then not run.

Went over this morning, pulled his HDM, FCM LVPS all OK.
HVPS, Fuse has exploded, only 1 end of the fuse left in the holder, the rest in all small pieces.
No other visible damage to anything else.

Anyone know the cause, or had this happen??
Should I replace the fuse and fire it up?? don't want to damage anything in my projector testing it.

I will post a pic later when I get a chance.

Appreciate any commments
Cheers
Steve

Sparky015 · Posted: Fri Jun 11, 2010 1:23 pm Post subject:

wow, the fuse exploded! It's possible the fuse went bad, but there is the greater likelyhood that something else is wrong, most likely a huge short. Short of building a test bed and slowly powering it up with a variac, I think all you can do is pop another fuse in and see if it blows again, then you'll know if you have a bad HVPS or just a bad fuse. I would think if it was a bad HVPS and the fuse exploded, that the short is in the potted section, in which case it's shot. I don't think there is a reliable method to repair it. That's my opnion, anways.

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

I think Sparky is right. there are some pics floating around here recently Steve of the Potted HV section. And if I am not mistaken didnt you modify that section per Chris Stevens mods he has done there in your own HVPS? But id look at the 390 v section coming out of the LVPS as well. Most likley the Transformer in the potted section either shorted or one of the HV diodes in that section failed.

Athanasios

**Curt Palme** · Posted: Fri Jun 11, 2010 1:50 pm Post subject:

I'd say it's a fluke. Most likely there is a short on the MOSFETS in the set, but those fgass fuses aren't guaranteed to be explosion proof when they blow, which is why Barco's original fuses are all sand filled, which are considered explosion proof.

Of course they are more expensive than the glass fuses, which is why no one uses them. Smile

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

Whats the number on the supply? X what?s

HK-Steve · Posted: Fri Jun 11, 2010 6:36 pm Post subject:

The power supply is from a 2004 Ultra.
10-000310-02 Issue
Model X2532

Here are some cool pics

Cheers
Steve

HK-Steve · Posted: Fri Jun 11, 2010 6:40 pm Post subject:

Curt,
Which mosfets are you talking about, inside the HVPS??

Appreciate all the comments,
I just don't want to damage my projector, as the World Cup is on in South Africa ATM.

Go Soccerroos, Australia for those not into soccer.

Cheers
Steve

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

The mosfets are in the HVPS but not in the potted section. If my print is right the mosfets are Q1 and Q2 and should be mounted on a heatsink. Between the mosfets and that fuse are some diodes......CR3, CR4, CR5 and CR6. You may want to check them also. might want to check C1 and C2 also.

HK-Steve · Posted: Fri Jun 11, 2010 8:40 pm Post subject:

The mosfets and the diodes check put ok on my meter.
The caps also are good on my cap tester.

looks like a new HVPS is needed.

Appreciate the advice and tips

Cheers
Steve

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

What does the other piece of the fuse with the wire in look like?

Sparky015 · Posted: Fri Jun 11, 2010 11:39 pm Post subject:

Steve, I would at least try a new fuse. It may not be it, but it's cheap enough before you put a fork in it.

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

oh and if you replace it put a sand filled fuse in. Mr. Green

JustGreg · Joined: 07 Mar 2006 Posts: 3098 Location: Kenosha, WI

Out of curiosity, Is the nuked fuse rated correctly?

Tom.W · Joined: 09 Mar 2006 Posts: 6635

Also is it possible the power company just had a voltage spike ?

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

I dont think he wants to try another fuse and he has the unit at his house and doesn't want to blow anything in his own PJ.

2004 ultra, hats the same year as mine. uh oh ! Wink

Nashou

Tom.W · Joined: 09 Mar 2006 Posts: 6635

Understood but Steve why are testing this on your working projector instead of the one in question ? Try a quick blow fuse at 75% the rating of the original fuse and see what happens on the projector in question.

HK-Steve · Posted: Sat Jun 12, 2010 6:53 am Post subject:

The projector is 1 hr drive away, so a long way to go and blow a fuse.

The rest of the fuse was shattered glass, very small pieces, the other end cap of the fuse showed the same burn mark on it, there was no fuse wire left at all.

The fuse is the correct size.

Cheers
Steve

HK-Steve · Posted: Sat Jun 12, 2010 6:56 am Post subject:

Don't think there are any issues with a power spike, as it happened at turn "on"

Would be pretty bad luck to get a spike just as the projector was turned on, plus no equipment in the same room has any damage. So I ruled this out.

Cheers
Steve

stefuel · Posted: Sat Jun 12, 2010 11:01 am Post subject:

The fuse is doing it's job. If it's the supply, it will blow again no matter what PJ it's in. You could pull a mac and build a test rig with a in-line fuse of the correct amps, a in-line amp meter and booted gator clips on each end. You could clip the rig in place of the fuse in your good running supply and see how many amps yours starts and runs at. Then you could install his and check his. If anything looks funky on the meter pull one clip off. Although if something is bad, it would probably pop the fuse before you could pull a clip. If it doesn't blow, you'll have amp readings to match with yours. If the amp readings match, put the fuse back in and go with it.

My first cup of coffee thought for the day.

**Curt Palme** · Posted: Sat Jun 12, 2010 1:19 pm Post subject:

I have a special sized nail to fit fuse holders that keep blowing those pesky fuses. Smile