Please help.

snork · 7th June 2004, 04:27 PM

I found an old pioneer amp(SA-610) laying around.

It does'nt work, and when I opened it up, I found 4 blown transistors.

My problem is that I can't find the markings in the standard transistor codes.

All four transistors have 'c1914 A02g' marked on them.

My knowlege of all things electric is pretty basic, and I would like to know what those markings translate to in standard codes (I thought maybe 2s********, but I'm not at all sure.)

What could be a possible modern replacement.

A good question is also, what could have caused four transistors of the same type to blow? All the other parts seem OK, and the there are no other 'c1914' types.

dhaen · 9th June 2004, 07:33 AM

Quote:

I thought maybe 2s********

You are probably right in your presumption: 2SC1914
Are you sure they're faulty?

Nothing special:

TO92 ecb

VCB 90V
VCE 90V
VEB 5V
IC MAX 50mA
P tot 200mW
FT 75 MHz
hfe 250 @ 1mA

snork · 9th June 2004, 11:09 AM

One is split down the middle, the other three are all black with the top half missing(blown off).

Do you know how something like this could have happened? I don't want to replace the transistors just to have them blow again.

snork · 12th June 2004, 12:21 AM

Would it be safe to test a pair of speakers once I replace the transistors?

dhaen · 12th June 2004, 09:40 AM

They were most probably blown because another device - one or more power tansistors have failed.
Changing these alone will only blow up another set. Sorry..

snork · 22nd June 2004, 11:34 AM

Hm,
Is there any way to test what the problem is?

7th June 2004, 04:27 PM	#1
snork diyAudio Member Join Date: Jun 2004 Location: geneva	Please help. I found an old pioneer amp(SA-610) laying around. It does'nt work, and when I opened it up, I found 4 blown transistors. My problem is that I can't find the markings in the standard transistor codes. All four transistors have 'c1914 A02g' marked on them. My knowlege of all things electric is pretty basic, and I would like to know what those markings translate to in standard codes (I thought maybe 2s********, but I'm not at all sure.) What could be a possible modern replacement. A good question is also, what could have caused four transistors of the same type to blow? All the other parts seem OK, and the there are no other 'c1914' types.

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9th June 2004, 11:09 AM	#3
snork diyAudio Member Join Date: Jun 2004 Location: geneva	One is split down the middle, the other three are all black with the top half missing(blown off). Do you know how something like this could have happened? I don't want to replace the transistors just to have them blow again.

12th June 2004, 12:21 AM	#4
snork diyAudio Member Join Date: Jun 2004 Location: geneva	Would it be safe to test a pair of speakers once I replace the transistors?

12th June 2004, 09:40 AM	#5
dhaen diyAudio Moderator Emeritus Join Date: Jun 2002 Location: U.K.	They were most probably blown because another device - one or more power tansistors have failed. Changing these alone will only blow up another set. Sorry..

22nd June 2004, 11:34 AM	#6
snork diyAudio Member Join Date: Jun 2004 Location: geneva	Hm, Is there any way to test what the problem is?

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