I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good time
for a Huntron. But no matter what I do I can't seem to isolate the problem.
It seems where ever the fault is it influences the whole board. Is there a
technique or tool I can use to figure out where the problem is? I can't
apply power because it needs the whole setup to run and it is far away in a
crowed busy place. Any helpful ideas out there for me.
Thanks
Russ

"russ lavergne" wrote in message
news:KfEBf.2092$AV.429@trnddc07...
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good time
for a Huntron. But no matter what I do I can't seem to isolate the
problem. It seems where ever the fault is it influences the whole board.
Is there a technique or tool I can use to figure out where the problem is?
I can't apply power because it needs the whole setup to run and it is far
away in a crowed busy place. Any helpful ideas out there for me.
Thanks
Russ
Might be helpful to know what the problem is. I repair some boards for a
commercial operation, that has machines that use them all over the place. In
theory, these need the rest of the machine as well, but by providing these
boards with power on the bench, and then simulating the inputs with
switches, the CPU clock and strobe signals with a couple of 555 timers and
the output loads with power resistors with LEDs across them, I am able to
carry out full diagnostic checks on every aspect of the board's operation,
and repair them with absolute confidence. Might be possible to do the same -
especially if you are likely to have to do more ??

Arfa

"russ lavergne" wrote in message
news:KfEBf.2092$AV.429@trnddc07...
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good time
for a Huntron. But no matter what I do I can't seem to isolate the
problem. It seems where ever the fault is it influences the whole board.
Is there a technique or tool I can use to figure out where the problem is?
I can't apply power because it needs the whole setup to run and it is far
away in a crowed busy place. Any helpful ideas out there for me.
Thanks
Russ

The first step to any effective troubleshooting is to understand the
function of the circuit. Without that info you can't really do very much.
Next you have to understand the individual components and their relation to
the function of the circuit. What does the board do? What are its inputs
and outputs? What components are these ICs and transistors that you listed?

Leonard

"russ lavergne" wrote in message
news:KfEBf.2092$AV.429@trnddc07...
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good time
for a Huntron. But no matter what I do I can't seem to isolate the
problem.
It seems where ever the fault is it influences the whole board. Is there
a
technique or tool I can use to figure out where the problem is? I can't
apply power because it needs the whole setup to run and it is far away in
a
crowed busy place. Any helpful ideas out there for me.
Thanks
Russ

Here's a thought...... maybe only practical if the IC's are
through-hole (not surface mount).
I was faced with a similar problem which involved a car wash facility
with about a dozen exact duplicate PCB's (and one spare!). Instead of trying
to reinvent the entire operation (no schematics or manuals, of course), I
noted that new IC's were available for about $.30 each, and the transistors
were even less. Just change them all! Didn't take much more time than first
troubleshooting and then repairing (which involved replacing something
anyhow)
Dumb, stupid and lazy? You bet! But, hey.... I could get the car wash
up and running pretty darn quick.
Old Chief Lynn

russ lavergne wrote:
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good time
for a Huntron. But no matter what I do I can't seem to isolate the problem.
It seems where ever the fault is it influences the whole board. Is there a
technique or tool I can use to figure out where the problem is? I can't
apply power because it needs the whole setup to run and it is far away in a
crowed busy place. Any helpful ideas out there for me.
Thanks
Russ




What's wrong with the boards? A DMM with a diode check function is
probably the best tool for the job, just test all the transistors,
they're the most likely fault in a machine like that which drives motors
or lamps.

James Sweet wrote in
news:I9OBf.32350$jd5.18427@trnddc02:

russ lavergne wrote:
I am working on a little board that is part of a big coin
op
redemption piece. It has 5 IC's 12 TIP22 transistors a
bunch of caps
on the IC's. another transistor and two other electrolytic.
There
are five of these boards. All exact duplicates. So I
thought that
this would be a good time for a Huntron. But no matter
what I do I
can't seem to isolate the problem. It seems where ever the
fault is
it influences the whole board. Is there a technique or
tool I can
use to figure out where the problem is? I can't apply
power because
it needs the whole setup to run and it is far away in a
crowed busy
place. Any helpful ideas out there for me. Thanks
Russ




What's wrong with the boards? A DMM with a diode check
function is
probably the best tool for the job, just test all the
transistors,
they're the most likely fault in a machine like that which
drives
motors or lmps.


--

"Receive to it the right in top you, kissing you the stupid
hun and kiss
your team like well." - Glasweigan
"we are total pricks!" - ZB
"We are tramps ****ed" - Paddy

We're in Europe and you're no.

I'm LOVIN' it.

"Receive to it the right in top you, kissing you the stupid
hun and kiss
your team like well." - Glasweigan
"we are total pricks!" - ZB
"We are tramps ****ed" - Paddy

We're in Europe and you're no.

I'm LOVIN' it.

http://www.yourdictionary.com/ahd/pron/J0002500.wav

"russ lavergne" wrote in message
news:KfEBf.2092$AV.429@trnddc07...
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good time
for a Huntron. But no matter what I do I can't seem to isolate the
problem. It seems where ever the fault is it influences the whole board.
Is there a technique or tool I can use to figure out where the problem is?
I can't apply power because it needs the whole setup to run and it is far
away in a crowed busy place. Any helpful ideas out there for me.
Thanks
Russ


In this scenario, your best approach might be to get a known good board and
record (sketch) the Huntron waveforms on each of the ICs and transistors.
Then you can compare the waveforms on the bad boards to the good one and
come up with a likely bad component.

Another approach could be to try to reverse engineer the circuit and draw a
schematic. That would certainly help you to analyze the problems. The
circuit schematic would also allow you to design and build a test setup that
would simulate normal inputs and allow you to analyze the outputs.

What kind of ICs are on the boards? Download datasheets from the internet
to help you determine what's working and what isn't.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in
the address)

Never take a laxative and a sleeping pill at the same time!!

I will answer each question as I go along. Thanks for all of the feedback.
It is a row of lamps part of 5 rows. and it just doesn't light up. I have
no schematic and I don't know where, or if the power inputs would do
anything. It is from a game called Cyclone. there are lights that go
around and you press a button and try and stop it on a particular light that
has the most tickits. I don't think it would be practical to work up a
setup as described. There is only one of these games.
Thank you
Russ
"Arfa Daily" wrote in message
...

"russ lavergne" wrote in message
news:KfEBf.2092$AV.429@trnddc07...
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good time
for a Huntron. But no matter what I do I can't seem to isolate the
problem. It seems where ever the fault is it influences the whole board.
Is there a technique or tool I can use to figure out where the problem is?
I can't apply power because it needs the whole setup to run and it is far
away in a crowed busy place. Any helpful ideas out there for me.
Thanks
Russ
Might be helpful to know what the problem is. I repair some boards for a
commercial operation, that has machines that use them all over the place.
In theory, these need the rest of the machine as well, but by providing
these boards with power on the bench, and then simulating the inputs with
switches, the CPU clock and strobe signals with a couple of 555 timers and
the output loads with power resistors with LEDs across them, I am able to
carry out full diagnostic checks on every aspect of the board's operation,
and repair them with absolute confidence. Might be possible to do the
same - especially if you are likely to have to do more ??

Arfa

Well, this board is one of five that controls a ring of lights. But I can't
work on it while it is put toghter. I don't have a schematic and the chips
are 74HC14 74HC273 74HC373 and Ten Tip22, one other transitor, two
electrolytics, and 8 ceramic caps next to the IC's. Is there no way to
troubleshoot without power and schemtics?
Thanks
Russ
"Leonard Caillouet" wrote in message
news:awKBf.14784$bF.1004@dukeread07...

"russ lavergne" wrote in message
news:KfEBf.2092$AV.429@trnddc07...
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good time
for a Huntron. But no matter what I do I can't seem to isolate the
problem. It seems where ever the fault is it influences the whole board.
Is there a technique or tool I can use to figure out where the problem is?
I can't apply power because it needs the whole setup to run and it is far
away in a crowed busy place. Any helpful ideas out there for me.
Thanks
Russ

The first step to any effective troubleshooting is to understand the
function of the circuit. Without that info you can't really do very much.
Next you have to understand the individual components and their relation
to the function of the circuit. What does the board do? What are its
inputs and outputs? What components are these ICs and transistors that
you listed?

Leonard

I ended up doing this, but there has to be better faster way. ????
"Lynn Coffelt" wrote in message
...

"russ lavergne" wrote in message
news:KfEBf.2092$AV.429@trnddc07...
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good
time
for a Huntron. But no matter what I do I can't seem to isolate the
problem.
It seems where ever the fault is it influences the whole board. Is there
a
technique or tool I can use to figure out where the problem is? I can't
apply power because it needs the whole setup to run and it is far away in
a
crowed busy place. Any helpful ideas out there for me.
Thanks
Russ

Here's a thought...... maybe only practical if the IC's are
through-hole (not surface mount).
I was faced with a similar problem which involved a car wash facility
with about a dozen exact duplicate PCB's (and one spare!). Instead of
trying
to reinvent the entire operation (no schematics or manuals, of course), I
noted that new IC's were available for about $.30 each, and the
transistors
were even less. Just change them all! Didn't take much more time than
first
troubleshooting and then repairing (which involved replacing something
anyhow)
Dumb, stupid and lazy? You bet! But, hey.... I could get the car wash
up and running pretty darn quick.
Old Chief Lynn

All of the trans check ok, I think it was one of the chips but how to you
isolate a chip problem with out power?
"James Sweet" wrote in message
news:I9OBf.32350$jd5.18427@trnddc02...
russ lavergne wrote:
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good
time for a Huntron. But no matter what I do I can't seem to isolate the
problem. It seems where ever the fault is it influences the whole board.
Is there a technique or tool I can use to figure out where the problem
is? I can't apply power because it needs the whole setup to run and it
is far away in a crowed busy place. Any helpful ideas out there for me.
Thanks
Russ


What's wrong with the boards? A DMM with a diode check function is
probably the best tool for the job, just test all the transistors, they're
the most likely fault in a machine like that which drives motors or lamps.

That is what I did with the Huntron but every chip shows problems. I know
every chip is not bad. I think the one bad chip influences the circuit and
makes all chips look bad. Or maybe I am doing something wrong.?
"DaveM" wrote in message
. ..
"russ lavergne" wrote in message
news:KfEBf.2092$AV.429@trnddc07...
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good time
for a Huntron. But no matter what I do I can't seem to isolate the
problem. It seems where ever the fault is it influences the whole board.
Is there a technique or tool I can use to figure out where the problem is?
I can't apply power because it needs the whole setup to run and it is far
away in a crowed busy place. Any helpful ideas out there for me.
Thanks
Russ


In this scenario, your best approach might be to get a known good board
and record (sketch) the Huntron waveforms on each of the ICs and
transistors. Then you can compare the waveforms on the bad boards to the
good one and come up with a likely bad component.

Another approach could be to try to reverse engineer the circuit and draw
a schematic. That would certainly help you to analyze the problems. The
circuit schematic would also allow you to design and build a test setup
that would simulate normal inputs and allow you to analyze the outputs.

What kind of ICs are on the boards? Download datasheets from the internet
to help you determine what's working and what isn't.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters
in the address)

Never take a laxative and a sleeping pill at the same time!!

"russ lavergne" wrote in message
news:OiSBf.38334$Me5.2515@trnddc05...
That is what I did with the Huntron but every chip shows problems. I know
every chip is not bad. I think the one bad chip influences the circuit
and makes all chips look bad. Or maybe I am doing something wrong.?
"DaveM" wrote in message
. ..
"russ lavergne" wrote in message
news:KfEBf.2092$AV.429@trnddc07...
I am working on a little board that is part of a big coin op redemption
piece. It has 5 IC's 12 TIP22 transistors a bunch of caps on the IC's.
another transistor and two other electrolytic. There are five of these
boards. All exact duplicates. So I thought that this would be a good
time for a Huntron. But no matter what I do I can't seem to isolate the
problem. It seems where ever the fault is it influences the whole board.
Is there a technique or tool I can use to figure out where the problem
is? I can't apply power because it needs the whole setup to run and it is
far away in a crowed busy place. Any helpful ideas out there for me.
Thanks
Russ


In this scenario, your best approach might be to get a known good board
and record (sketch) the Huntron waveforms on each of the ICs and
transistors. Then you can compare the waveforms on the bad boards to the
good one and come up with a likely bad component.

Another approach could be to try to reverse engineer the circuit and draw
a schematic. That would certainly help you to analyze the problems. The
circuit schematic would also allow you to design and build a test setup
that would simulate normal inputs and allow you to analyze the outputs.

What kind of ICs are on the boards? Download datasheets from the
internet to help you determine what's working and what isn't.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters
in the address)

Never take a laxative and a sleeping pill at the same time!!



A way that I've used in the past to reverse engineer a board and determine a
schematic for it, is to photocopy the print side, then draw on the actual
parts, but in schematic form rather than physical form. You can then derive
the schematic trace by trace, scribbling them out on the photocopy as you
go, using a coloured felt tip pen. From the number of components on the
board, and the simple logic function ICs, should be practical in your case.
I suppose these days, you could probably do the same thing with a scanner
rather than photocopier.

Arfa

"russ lavergne" bravely wrote to "All" (25 Jan 06 21:40:46)
--- on the heady topic of " Repair method"

rl From: "russ lavergne"
rl Xref: core-easynews sci.electronics.repair:356515

rl Well, this board is one of five that controls a ring of lights. But I
rl can't work on it while it is put toghter. I don't have a schematic
rl and the chips are 74HC14 74HC273 74HC373 and Ten Tip22, one other
rl transitor, two electrolytics, and 8 ceramic caps next to the IC's. Is
rl there no way to troubleshoot without power and schemtics?
rl Thanks
rl Russ


With such few jellybean IC's might it not be logical to simply change
them all wholesale style and never develop a migrain over it?
It is an infallible way to fix it after all!

A*s*i*m*o*v

.... Enter any 12-digit prime number to continue.