a73camaro

I ran across this today.


Subject: Re: Pocket Programmer Info?

"Mark S. Riley" wrote:

> Sometime back a few months, someone posted a note about the pocket
> programmer loosing voltage and not programming chips. Transistor is bad, I
> think, and posted the common replacement number for it. I've killed mine
and> have searched the archives for GMECM and DIY-EFI using the word "pocket"
and
> returned several things but not that info. The Archives are very nice. If
> you have this info could you repost or send to me. Many Thanks, Mark Riley


Sorry I missed that thread, but since I have a Pocket Programmer I can crack
it open and take a look -

In the switching power supply area on the bottom of the pc board, there are
two
active components in it - a 7805 voltage regulator and a 2N4401 transistor.

According to NTE Inc. -
http://www.nteinc.com/

the 2N4401 is your garden variety NPN switching transistor. They list it as
an NTE123AP, although looking at the specs, I can't see why you can't use
a 2N2222 (NTE123A) (the "P" has a little better settling time).

So there ya go - if you have an NTE stocking dealer, get the NTE123AP,
otherwise use a 2N2222 from Radio Shack. They also have the regulator
if you need that. The other transistors on top of the board are 2N3906
(NTE159), 2N3905 (also NTE159), and another 2N4401. None of these should
be hard to find at your local shops.

While you have it open, make sure you have .001 caps to ground on pins 1, 2,
& 3 of the 74HC138 to help out with noise.

-|-|-|-|-|-|-|-|-
|16 9 |
| |
] 74HC138 |
| |
|1 2 3 4 5 6 7 8 |
-|-|-|-|-|-|-|-|-
| | | | | |
- - - | | |
.001uf X 3 - - - | | |
| | | | | |
V V V V V V Ground


And the latest version of software is Win 1.13. Hope this helps!

- -- Kris