CurtPalme.com Home Theater Forum

Zook94 · Joined: 21 Nov 2006 Posts: 19

I have a NEC PG9, and I am on my 4th C drive in this unit in 4 years. I bought it with a bad drive, unknowing it was bad, and have replaced it 3 additional times since installation. This last issue I think is my fault, I had my teenager put the boards back in the unit, and upon inspection, the furthest screw on the second STK is missing. Could that cause failure? What other than those STK's go bad regularly on the C drive?

I need quick help, the Michigan/Michigan State game is right around the corner, and if Mama doesnt have HDTV, well, you know....

Thanks.

Mark_A_W · Posted: Fri Oct 26, 2007 12:12 am Post subject:

Interesting.

I've owned 5 or 6 PG Xtras and an XG, and 4 of the Xtras were bought broken.

I've never seen or had to work on a NEC with a bad STK chip or C drive/F drive/A drive. None of my broken Xtras had bad drives.

I think there is something wrong with your chassis or setup. Add some heatsinks and fans to the bottom plate, opposite the C drive, at the very least.

stefuel · Posted: Fri Oct 26, 2007 10:42 am Post subject:

1. Marathon convergence sessions can cause premature stk failure. Make a few changes then take a break.
2. Lack of heat transfere paste between the stk and chassis will cause failure.
3. Poor mechanical set-up with large electronic correction could cause it.
4. Aftermarket stk's have been known to fail pre-maturely.
5. If the projector is hung, check the aluminum base (which is now facing up) for a buildup of dust. The base is one large heatsinc. Dust acts as a insulation and holds the heat in the aluminum.

But then what do I know? I'm a AmPro guy

Dave Lister · Posted: Fri Oct 26, 2007 11:41 am Post subject:

Could that missing screw be causing a short circuit?

dbaisey · Posted: Fri Oct 26, 2007 2:26 pm Post subject:

Chip's list has everything covered and Marks suggestion does help adding a external heat sync. Some of the overheating is from the F drive right next to the C drive. The combined heat transfer of the two can cause problems on the bottom plate if the set up is a bit taxed.

Are you having a problem now or are you talking preventative? If your not having a issue now I would leave it alone until after your game. If your rebuilding the same drive board each time I would stock a different one to have as a spare. The other problem a C drive can have is the connector solder joints can become weak from abuse. The connectors sticks up quite a ways. Wiggle each lightly and see if it affects the problem color esp if your using the same board to rebuild. Doug

Zook94 · Joined: 21 Nov 2006 Posts: 19

I wouldn't mess with it if it weren't broken. I think I may have found the cause, searching through old posts. I found a picture of the connectors that set the actual drive parameters. Mine were a little different. I recieved this projector in working order, and so when things got put back together, they were reconnected in the wrong order again. STK's should be here today, I will find out soon.

**Curt Palme** · Posted: Fri Oct 26, 2007 3:08 pm Post subject:

Counterfeit chips can also cause issues.

dbaisey · Posted: Fri Oct 26, 2007 3:16 pm Post subject:

Yes I have seen a few drives with those. Numbers look to be painted on. Doug

**kal** · Posted: Fri Oct 26, 2007 4:29 pm Post subject:

Thread title changed to something useful.

Kal

Zook94 · Joined: 21 Nov 2006 Posts: 19

**Curt Palme** · Posted: Sat Oct 27, 2007 12:04 am Post subject:

Also, the back heat sink metal can warp, so that a good portion of one or both chips doesn't touch the actual chip. Seen a few of those... That will cause premature failure.

Zook94 · Joined: 21 Nov 2006 Posts: 19

Zook94 · Joined: 21 Nov 2006 Posts: 19

Ack! I got counterfiet chips. Got the new chips in and let the set warm up. I decided to set the static image.

Controls didn't do what I expected. Everything was connected correctly, but when I moved the red crt vertical controls, it controlled green vertical movement?? I shut everything off, triple checked connections, then turned it back on. I decided to find out what was really happening. When I used blue horizontal controls the red crt moved. Green horizontal made red move. Red made green move. Thats as far as I got before it shut itself off. It sat and crackled and sizzled for a couple minutes (I was hoping it would catch on fire) but after 15 minutes I decided to unplug it. My wife stole her mirror back, so I can't really see the panel for a trouble code. I was thinking more like pinata party.

Needless to say, the big game this weekend will NOT be broadcast in HDTV in my residence. At least I have my 1031 to fall back on.

Zook94 · Joined: 21 Nov 2006 Posts: 19

So every time this set has failed in the last week, it has taken the .33 resistor next to the power connector on the C drive. I took it over to my favorite TV repair shop, and had a friend check it over with his multi meter. He even got out his little sight glass to check out solder joints to make sure none were shorted out. I'm at a loss. Every component on the board matches what it says its supposed to be on the component, and I have had 3 different sets of STK chips in it. The picture works fine until the resistor blows, and the diagnostic goes F8. Unplugging the C drive, the projector powers up and shows a picture, out of convergence of course, but none the less, it works. I'm stumped. I don't want to buy another board just to have it blow on me just like the current one is doing.

Anyone? Bueller?

**Curt Palme** · Posted: Tue Oct 30, 2007 8:04 pm Post subject:

Send it up if you want. It's a seemingly simple board, but with lotsa problems on it.

Mark_A_W · Posted: Sun Nov 04, 2007 9:42 pm Post subject:

Get a new board!