CurtPalme.com Home Theater Forum

CIR Engineering · Posted: Fri Sep 26, 2008 9:58 pm Post subject:

**JohnHWman** · Posted: Sat Sep 27, 2008 10:10 am Post subject:

kschmit2 · Posted: Sat Sep 27, 2008 11:50 am Post subject:

CIR Engineering · Posted: Sat Sep 27, 2008 2:35 pm Post subject:

[QUOTE=macgyver655;14750006]I believe Ten Four requires you to order a minimum of 5 mosfet's. B&D has them as individuals.

http://www.bdent.com/search/part.jsp?partnum=2SK2349[/QUOTE]

WOW, great link. They also have some of the other parts I need. Can someone help me with D608? I am having trouble figuring out what it is part number RD20ESB2. I found this, but don't know if it is correct or not:

**JohnHWman** · Posted: Sat Sep 27, 2008 5:21 pm Post subject:

CIR Engineering · Posted: Sat Sep 27, 2008 9:27 pm Post subject:

I ordered this one http://www.bdent.com/search/part.jsp?partnum=GZB20.0B as I got all the other parts from them already.

craigr

**JohnHWman** · Posted: Sun Sep 28, 2008 7:12 am Post subject:

Fine Craig,

B&D is the source when I need STK Sanyo hybrid amplifiers used for CRT MG coils drivers Smile

Please check other PA power surrounding components health to be sure that there is no more hidden failure(s)

John

CIR Engineering · Posted: Sun Sep 28, 2008 1:00 pm Post subject:

CIR Engineering · Posted: Fri Oct 03, 2008 7:49 pm Post subject:

FIXED!!!!

craigr

Nashou66 · Posted: Fri Oct 03, 2008 8:14 pm Post subject:

CIR Engineering · Posted: Fri Oct 03, 2008 8:24 pm Post subject:

Frank D · Joined: 20 Jun 2006 Posts: 65

CIR Engineering · Posted: Sat Oct 04, 2008 2:29 pm Post subject:

So I was thinking about it and there isn't really any type of write up to do for this. Basically, if you can do component level repair then I would suggest pulling out the PA and trouble shooting it Neutral

However, if you loose HV without an error code, it's a good bet that the PA is at fault. If you have a high voltage probe, measure the voltage at pin 1 or pin 2 of CN89 or CN90. You should see a HV waveform or 875 volts pp.

If there is no waveform (or if you don't own an HV probe), the first thing to do would be to pull the PA board. But before that, you must drain off the 200 volt section with a resistor, or let the board set for two hours with the G90 unplugged.

Once the board is out, test the six fusible links R614~R619. You can test them in circuit, and if they measure much higher than 0.1 mega ohms then the fusibles are blown. Fusibles being blown will most likely indicate that there are other problems on your PA board.

The good news is that the high voltage section of the PA isn't that complicated. So use your judgment to measure any components that might be part of the problem. You will probably need to pull a lot of the HV components off the PA board to make the measurements.

On my PA the following parts were blown and I replaced them.

The three 1500 volt MOSFET transistors Q600~Q602.
The six 19.2 volt zener diodes D601, D602, D604, D605, D607, D608.
The six fusible links R614~R619.

I also replaced transistors Q503~508 as John pointed out that they are in phase with the big dogs Q600~Q601. The big transistor were $75 each and the little Q503~Q508 transistors were only $6 total. The Q503~Q508 transistors tested good, but sometimes transistors can test good and still be blown. I figured I would spend the extra $6 bucks to help ensure that I did not ruin the $225 transistors on the other side.

Here are some links for parts. Some were provided by friends here and on AVS and some I found myself.

Best prices and excellent customer service, but you will need to make substitutions.
http://www.bdent.com/index.jsp

Good but has order minimums.
http://www.tenfourltd.com/index.php

Expensive, but they have EVERYTHING with no minimums.
http://www.nexttronics.com/

Expensive, but they have some things although many are special order with a delay.
http://www.ued.net/website/index.html

I'd also like to thank everyone who helped and provided moral support including JohnHWman, tse, and macgyver655.

craigr

CIR Engineering · Posted: Sat Oct 04, 2008 2:31 pm Post subject: