Transistor ID...

Oct 13, 2010 6 Replies

Posted this at sci.electronics.basics; got redirected to here. Hope someone can help:



Have a broken inverter on a 2000fp Dell LCD monitor.



One of the transistors is visibly fried on the board.



Can anyone help me ID what type of transistor it is, and where I could source a replacement?



Markings on it: DT QX



Q12 in the photo linked below.



Photo:

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Thanks.


have a peek at

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and the SMD codebook lists DT as:

SGS BCW67AR SOT23R PNP 32V 0.8A Hfe 100min

Per

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it is a Rohm 2SD2391 Sources include both Mouser and Digikey in the US, eBay in the UK, and countless sites in the Far East.

PlainBill

I sort of like the layout of that board.

I was just working on a Vivitar 285 camera flash- talk about pile of junk that looks like, and was designed in the 1970s. Parts crammed in every direction, wires all over the place, strange daughterboards, junk and spacers that just fall out once you open it etc. Yuck.

Thanks everyone for the info (and thanks for the post at badcaps as well, PlainBill).

Have sourced a seller on eBay UK, so I'm good to try this one component in the first instance. I got the monitor for nothing, so it's worth a punt at least.

Cheers.

This circuit is a Royer oscillator, infamous for failures in Benq, Dell, and HP monitors. Always replace both transistors if one is bad. Also resolder the inverter transformer, and check for shorted diodes. The poly capacitor is also an item of concern - make sure it's properly soldered.

Good luck

PlainBill

In the UK they are available from Farnell.

PlainBill

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