Transistor 29999, Need help identifying this.

69Camaronut

New Member

• Jun 29, 2013

• #1

Can anyone identify this transistor. I'm looking for a Datasheet on it. I can't seem to find it in any of my books. I've never seen a a number with a circle around it. I tried looking it up as 2N9999 and still nothing.

 

Roff

Well-Known Member

• Jun 29, 2013

• #2

69Camaronut said:

Can anyone identify this transistor. I'm looking for a Datasheet on it. I can't seem to find it in any of my books. I've never seen a a number with a circle around it. I tried looking it up as 2N9999 and still nothing.View attachment 74562

Click to expand...

The numbers have obviously been added to the photograph. They are not printed on the transistor.

 

69Camaronut

New Member

• Jun 29, 2013

• #3

I added the part number text because its hard to see. Look across the lower section.
Also if you click on the first photo posted it has the actual dimensions of the part.
Here is the actual photo.

 

WTP Pepper

Active Member

• Jun 30, 2013

• #4

My guess purely down to seeing the odd transistor like it physically would be the 2N2926 series. The lower skirt is unusual on transistors these days.

https://tinyurl.com/ol2u7o4

Found by googling 2n2926

 

House0Fwax

Member

• Jun 30, 2013

• #5

The 2N3394 also came in that package, I've just found 7 of them in my transistor tray to look at.

 

69Camaronut

New Member

• Jun 30, 2013

• #6

This transistor was used from 1966-1975 by GM. I cant afford to guess at a replacement because it could set my 69 Z/28's electrical harness on fire. I've had the car 37 years and it would be nuts to experiment with it. Someone must know exactly that this is.

WTP Pepper, nice link, I haven't even been able to find another case style like this.

I have substitution books going back to 1971 but a local Electrical Parts Distributor said even though the part was used until 1975 it may have only been in production for a year or two and replaced by a better transistor.

 

Last edited: Jun 30, 2013

JimB

Super Moderator

Most Helpful Member

• Jun 30, 2013

• #7

The number is probably an "in-house" number from the company that made the circuit board.
Just to make it difficulty/impossible for users to arrange their own repairs.

Why do you think that this transistor is faulty?
Or, are you just trying to reverse engineer an old piece of equipment?

What is it anyway?

JimB

 

69Camaronut

New Member

• Jun 30, 2013

• #8

It stopped lighting up the Low Fuel lamp on the dash and I'd rather try to fix the original which is better to have and only a few cents for a transistor then to pay 55 dollars for a Chinese replica that a lot of friends have said burn out on occasion and take the fuel gauge with it.

 

Mr RB

Well-Known Member

• Jun 30, 2013

• #9

The 2Nseries ends at about 2N7xxx, and those high numbers are more modern parts, so it's very unlikely to be a 2N9999.

It will be easy enough to find a replacement if you post good photos of both sides of the PCB so we can work out the circuit. It's most likely just a small signal NPN.

 

MikeMl

Well-Known Member

Most Helpful Member

• Jul 1, 2013

• #10

69Camaronut said:

This transistor was used from 1966-1975 by GM. I cant afford to guess at a replacement because it could set my 69 Z/28's electrical harness on fire...

Click to expand...

bs, any low-level switching transistor will work. First thing you need to determine is if it is NPN or PNP. As long as the Vce is > 20V, there are probably are hundreds of general purpose transistors that will work...

 

V

vtech

Active Member

• Jul 1, 2013

• #11

That is the JEDEC TO-98 package which is obsolete---used back in the 70's.

"electrical harness on fire" Hu? It takes a LOT more to set the harness on fire than a simple shorted transistor.