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Equipment Repairs => PLASMA TV forum => Topic started by: delphi on May 18, 2007,09:15:11

Title: Hitachi CMP307XE
Post by: delphi on May 18, 2007,09:15:11

Hi,

This unit is dead. I found 2 chopper transistors dead. These were duly replaced.

Switched unit on, standby red light lit for 3 seconds before tripping the building trip fuse (Apparently this is a design feature of the unit) Now the unit doesn't go into standby, it just trips the fuse. Checked the following components, Bridge rectifier, Triac, Chopper transistor (associated with the standby circuit) Output rectifier diodes for standby supply. I'm thinking of checking the filter capacitors on the primary side of the psu, but in the meantime, does anyone know of any stock faults?

Unfortunately, the service manual does not allow repair to component level, so I've basically been using my own logic gained from repairing CRT smps.
Thanks for any help, maybe the filter caps are faulty, will let you know when I get around to checking them.

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Post by: cueboy on June 02, 2007,15:21:22

bin the thing he he

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Post by: delphi on June 21, 2007,08:34:36

Maaged to repair the PSU 2 transistors SC. A1884 and C3851, had to use sub BD909 for C3851.

But, that's not the end of it. The monitor and fans power up, green light lit, but the display is blank.

Any ideas? Apart from the bin it idea.

Thanks

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Post by: delphi on July 12, 2007,08:27:02

Ouick update, I've studied the service manual, which has more info than I first thought. 5v line is missing, so out with the PSU, again!. I will let you know what happens.

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Post by: delphi on July 26, 2007,06:51:21

5v line wasn't missing, the service manual has the wrong info on it!! Turns out the main 180v line is missing. As the choppers have been replaced, I'm looking to replace the FA5304A driver chip.

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Post by: delphi on October 16, 2007,04:36:46

Just to let you know the PSU is now working!!