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Datasheet wanted for Q165A diode

nimiq

Jun 30, 2019
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Hello, I have a Panasonic TV which does not switch on. The power supply board has two diodes that appear short circuit (<1ohm either way). They are labelled Q165A and I suspect they may be transient suppression diodes as they are part of the transformer circuit. Problem is are these common cathode, common anode or what? Unless I can find out I can't really fix the board. I've not found a circuit diagram either. PCB reference is TNPA5806 which seems to be used in a number of Panasonic Viera TVs.
Any ideas appreciated.
 

bertus

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Nov 8, 2019
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Hello,

Is the Q165A written on the part or the board?
I can not find anything for Q165A.
Where is the part on the board.

Bertus
 

Attachments

  • TNPA5806_board.jpg
    TNPA5806_board.jpg
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nimiq

Jun 30, 2019
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Hi Bertus,
Thanks for replying.
The part is on the back of the board under the large transformer to the left of the board picture. The part is marked on the case Q165A, nothing else. I think the package is DPAK, problem is the tab could be cathode or anode it may be one or two diodes internally I just can't even guess.
Roger
 

nimiq

Jun 30, 2019
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...oh and the PCB is marked D7408 and D7409 (two diodes appear shorted) that's how I figured it was a diode of some sorts.
Roger
 

bertus

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Hello,

I see more of those diodes on the back.
Unfortunately the markings can not be read.
I have used the pictures from this page to show:
https://www.ebay.com/c/1271470258

What is the type number of the TV?
Perhaps we can find a manual with more info.

Bertus
 

Attachments

  • TNPA5806_back_board.jpg
    TNPA5806_back_board.jpg
    401.2 KB · Views: 6

nimiq

Jun 30, 2019
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The board is similar to mine but my D7413 and D7412 are not populated (maybe a lower power rated board).
In the photo you've attached all the diodes look fried.
 

Martaine2005

May 12, 2015
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Sorry, I am on a train with only my phone. Hope the pictures help you identify the correct component.

Martin
 

nimiq

Jun 30, 2019
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Hi Martin,
Thanks, that's great, I think you've cracked it. I found the circuit diagram for a similar PCB late last night (TNPA5808) and the circuit diagram symbol showed common cathode diodes on the transformer output windings (see attached filename 7 should be a 5). That ties in with the datasheet you have found.

Many thanks to both yourself and Bertie for helping.
Roger
 

Attachments

  • TPNA7808.JPG
    TPNA7808.JPG
    77.4 KB · Views: 5

nimiq

Jun 30, 2019
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Ha!! I had been to the alldata website but did not realize you could select mark as a filter...learn something every day.
Thanks Martin
 
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