Need Help Identifying Transistors

[tuck05]

I am a complete newb at amp repair.

I am in the process of attempting to repair a Cadence txa-1000d. The amp would come on and go into protect and stay in protect. I found that the transistors at D13, D14, D40, and D41 were shorted out. I cut them off the board and the amp will now power up normally. I however cannot identify them. The only markings on the transistors are c25 59 02c and the other one says c25 67 02n. What transistors are they and where can I order quality replacements.

Thanks

 

[Minion]

Ususally on Schematics and PCB"s transistors are designated with a Q , like Q13 , Q14 Q40 ect , D usually means a Diode , are you sure they are transistors and not diodes ??

Anyways , maybe they are 2sc2559 ?? if they are they are a discontinued Japanese transistor , couldn"t find a Datasheet sorry .....

good luck

 

[Mooly]

Close up photo of them maybe ?

If they are output devices then there may be other problems... always power up with a "bulb tester" first... 100 watt bulb in series with the mains.

 

[tuck05]

I'm not sure what they are. I looked around on the net and the pictures I found that looked like the pieces were called transistors/mosfets.

I've been running the amp on 2 RE SX 15's wired to .5 ohm. I figured the output transistors burnt up seeing as how I've been running at it .5ohm for over a year now. I watched a vid on youtube and it showed a guy measuring measuring the "transistors" with a multimeter. I followed the vid and did the same thing he did. The 4 transistors I cut out measured real low ohms while the rest of them measured high ohms.

Maybe the pix will work.

Pictures by tuck - Photobucket

 

[Yurk]

I'm not sure, but I think they might be Super Barrier Rectifiers, something like this:

SBR40U60CT Diodes Inc.

Looks like you have two types, one pair with common cathode, and one pair with common anode.

I don't know how to tell what amperage rating you've got because I can't find those exact parts. Maybe this will help you get closer to finding them.

Yurk

Disclaimer: I'm an amateur. I reserve the right to be wrong. Your mileage may vary. Get a second opinion. Maybe a third opinion. etc.

 

[Yurk]

Or, they could be Switchmode Power Rectifiers, which I'd actually lean more towards. Again, couldn't find the exact part:

Rectifier On Semi

 

[infinia]

Take a better picture of the parts laying down outside w/o flash maybe.
more people with experience in the Car Audio Forum here???

Yea the D (diode) parts are similar to what Yurk found, the center pin is the common case, so most common type is the common cathode both arrows point in.

 

[Mooly]

There going to be hi-speed diodes for SMPS use.
Something like,
http://www.datasheetcatalog.org/datasheet2/7/0tgpx61uwi2i5sz8txqp59f5jcyy.pdf


Also to add a picture to a thread directly,


Too add a photo,
First click "go advanced" in the box below the "quick reply" message box. Doesn't matter if you decide half way through a message to do that, it carries it foward.

Then click "Manage attachements"
Click browse in the first box at the top and find your picture. Repeat for any more pictures.
Click upload... a message appears "uploading"
When complete, scroll down to the bottom of page and click "close this window"

The pictures should now be attached and when you post will appear. I don't think they show in message preview... they never used to anyway.

Make sure your pics aren't too big, a couple of 100k is plenty, and many object when they are massive and it alters the margins
It tells you in the attachments window what max sizes are allowed.