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Volume 9 Issue
Issues | Linux
Productivity Magazine ]
“Don't sweat the small stuff.” -- Proverb
By Steve Litt
"When you narrow the problem down to three or four transisters, shotgun
Those words were spoken by my electronics trainer at Pacific Stereo.
Knowing absolutely nothing about the process of troubleshooting, I
simply took him at his word and did exactly what he said. That was one
of the things that, over time, made me one of the fastest techs in the
Pacific Stereo's Chicago region.
If you haven't heard the term before, shotgunning is the act of
replacing multiple components, even though only one is the root cause.
The purpose of shotgunning is economic.
My instructor went on to explain the rationale behind his statement.
Each transistor cost roughly a dollar. The labor charge was typically
$39.00. Is the customer really going to care whether the total repair
charge is $40.00 or $43.00? Probably not. Will the customer care
whether I get the receiver back to him today or in 4 days.
Definitely. If every repair takes extra time, it can lead to repair
cycle avalanche, which occurs when the logistics of reassuring
customers of overdue units and maintenance of the masses of
to-be-completed units encroaches on actual troubleshooting time, which
in turn leads to slower throughput, which leads to more logistics and
This issue of Troubleshooting Professional Magazine is devoted to
shotgunning -- how to do it, when to do it, and perhaps most
importantly, when not to do it. As always, if you're a Troubleshooter,
this is your magazine. Enjoy.
This document discusses the practice of replacing functional parts. I
do that in my own repairs, and in the past I've done it in repair shop
environments. I was taught to do that at Pacific Stereo, within the
parameters of appropriateness. Doing so has raised my productivity
without significantly raising the customer's repair bill.
When repairing equipment belonging to others, and billing for those
repairs, it is possible, and perhaps likely in certain circumstances,
that replacing functional parts could get you in legal trouble or
saddle you with negative publicity from the media. You, or your
organization, needs to decide on your own policies, weighing increased
productivity against legal and publicity risks.
FOLLOWING THE ADVICE IN THIS DOCUMENT COULD GET YOU IN LEGAL TROUBLE OR
GARNER ADVERSE PUBLICITY, SO USE IT AT YOUR OWN RISK!
You use this document at your own risk. I am not responsible
for any damage or injury caused by your use of this document, or caused
by errors and/or omissions in this document. If that's not acceptable
you, you may not use this document. By using this document you are
accepting this disclaimer.
By Steve Litt
"Thirty nine dollars just to look at it???"
If you've ever worked in a retail repair shop, you've come to hate
those words. Customers think part replacement is the hard part of a
repair, and diagnosis is trivial.
Of course, you know that the
opposite is true. Parts replacement takes less than an hour in most
cases, but diagnosis can go on and on. That's why you shotgun. If you
can replace five cheap parts and save 20 minutes on the repair, then
somebody is saving money. If you charge by the hour, the customer is
saving money. If you charge flat rate, then you save the money, but you
save quite a bit more than the customer spends on the possibly good
parts. In such a case, an argument could be made that the customer is
actually saving money because shotgunning enables you to set your flat
charge lower on all customers.
By Steve Litt
Doesn't it seem like the better you get at troubleshooting, the more
intermittents you see? Six months ago an event occurred in which my computer simply
turned itself off. It never happened again.
Til last night. After I replaced a defective DVD+RW drive, click, it
went off. I noticed that the computer was plugged into a power strip
that was in turn plugged into the UPS. The power strip was cheap, old,
and the switch didn't seem to work too well. I went back to work,
wondering if the power strip was the root cause.
Click, it went off 20 minutes later. I got really mad.
I'd had a tough day. I was putting the finishing touches on a backup
program that is configurable from an outline. The bad DVD+R player had
made it look like my backup program didn't work, requiring hours of
needless debugging. Finally I exchanged the bad DVD+R, and it looked
like my backup program was working except for some minor details. But
it was 11 pm, and I was tired, and in no mood for any more problems.
If there's one thing I know, it's that you never troubleshoot when
you're mad. I knocked off, figuring tomorrow is another day. While I
was showering it occurred to me that it might be nice to perform a
couple general maintenance items and then leave the computer cooking
So I replaced the AC cord, and I lubricated the contacts where the
power supply connects to the motherboard. It's been 12 hours, and so
far, no clickoff. The next step will be to put the cover back on the
computer -- both events last night were with the case on.
Computer AC cords cost about $5.00 apiece, so I want to keep that AC
cord. But if the event doesn't recur within a couple days, I'm cutting
up that cord and throwing it away, even though it's more likely that
the problem was caused by corroded contacts between the power supply
and the motherboard.
Why would I do that?
The slowest reproducible problems to fix are the ones where a wrong
assumption isn't tested. Most such situations are avoidable, and shame
on the Troubleshooter if she doesn't test assumptions. But some
assumptions must remain untested for productivity. Chief among such
assumptions is the assumption that the "known good" part is really
good. If I put a suspicious cord back into my stash of cords, a couple
months down the road it could complicate a troubleshoot.
But wait, there's more. This cord isn't suspected only of being
defective, it's suspected of being intermittently
defective. Its use in a swap could cause a problem not detectable in
testing -- a problem that could crop up days or months after its
insertion. It could cost days of troubleshooting. $5.00 is a cheap
price to eliminate that possiblility.
In fact, I routlinely destroy and dispose of suspected intermittent
components. Chief among such components are computer IDE cables. If I
swap it out I'll probably trash it, unless it's quickly obvious that
the symptom occurs also with the new component. When a motherboard is
suspect in an intermittent, I'll trash it unless I can prove it's not
the cause. Yes, I'm throwing away $79.00, but I'm guaranteeing that it
won't cause an intermittent in the middle of a troubleshooting course.
When one or more components are implicated in an intermittent, unless
they can quickly be proven non-causes, the dumpster is your friend.
By Steve Litt
You're fixing a six year old, heavily used server computer with an
intermittent disk problem. Both its IDE cables and its floppy cables
are dusty and old. So you shotgun both IDE and the floppy cable.
Why did you do that?
Because in any reasonable preventive maintenance program, those cables
would have been replaced already. If there's not something wrong with
them now, there very well might soon be. Meanwhile, replacing them
might fix the problem. So you swap them, lubricate their electronic
contacts, and cook the computer to see if that fixed the problem. If
If you were doing this work for a customer, and if swapping the cables
didn't fix the problem, ethically you'd need to get the customer's
consent. Just let him know you can't warranty your work unless he
lets you replace the cables. That should do it.
Shotgunning is an excellent idea when dealing with old components that
should have been replaced under a preventive maintenance program.
HOWEVER, if you're in a repair shop environment, you must be aware that
even replacement of old but still functioning components could get you
a consumer affairs investigation or an undercover visit from the local
TV channel. In a repair shop environment where you repair other
people's gear, the best strategy is to tell the people exactly why you
want to replace the old but still functioning parts, possibly denying
them warranty if they do not, and then give them the choice.
By Steve Litt
There's a fine line between replacing good parts to make repair more
efficient, as opposed to replacing good parts because of incompetence
or greed. If you fall on the wrong side of that line, you just might
end up with some very bad media coverage, or even legal problems. Not a
year goes by when the media doesn't expose a repair facility for
"unneeded repairs", including some very large outfits that are
To be appropriate, the shotgunned parts should be cheap relative to the
entire repair. In the case of Pacific Stereo, the added cost was
usually less than 10%.
Second, at least one of the shotgunned parts should cure the problem.
Otherwise you're not shotgunning, you're practicing diagnosis by serial
replacement. Diagnosis by serial replacement at least causes customers
to hate you, and might get you on TV in a way you don't like.
Of course, the worst practice is performing unnecessary repairs to pad
the repair bill. That's illegal and unconscionable. Anyone doing that
should be put out of business.
Shotgunning Fair to the Customer?
In other words, is it ethical?
I think appropriate
shotgunning is fair to the customer, and is ethical. Here's why:
For one thing, if you charge by the hour of actual work, shotgunning
can lower the customer's bill. Reduced cost for an equivalent (or
better) repair seems obviously fair and ethical, at least to me.
If you charge a flat labor charge, and the added cost is not
significant, I still think it's fair. If it weren't for shotgunning,
you'd need to raise that flat labor charge. Maybe not as much as the
cost of the shotgunned parts, but you'd need to raise it for all
customers, even those needing no parts replacement. Given the cost of
the shotgunned parts is a small portion of the total bill, I think this
is fair and ethical.
As the cost of the shotgunned parts rises, fairness and ethics come
more into question. If you're unsure, perhaps the best policy is to
bring the customer into the loop. Perhaps you can explain that you
warranty only the parts replaced, and if other parts turn out
problematic, they'll need a costly new repair. If the parts are old,
describe the preventive maintenance advantages. Then let the customer
make the decision.
By Steve Litt
I am not a lawyer. I do not know whether it's legal. That's something you need to find out.
I imagine it varies from state to state. If you fix other people's
equipment, you should check this out with a lawyer or someone very
knowledgeable. If you fix your own equipment or the equipment of your
employer, legality is a moot point.
Please keep in mind that state attorneys general and investigative TV
reporters don't understand repair, and don't cut repair shops much
slack. Like most of the populace, they think that the bulk of the
repair is actual parts replacement, not determining which parts to replace. They look
with skepticism on honest mistakes.
These are issues you need to consider before shotgunning when repairing
equipment belonging to others.
Should I Shotgun?
By Steve Litt
There's no easy answer, so I won't answer that question. In this
magazine, I've tried to lay out information so you can make your own
I shotgun. I shotgun on repairs I do for myself, and for customer owned
equipment when I was in the stereo repair business. I shotgunned both
in my own shop, and in shops owned by others. I always made sure such
shotgunning didn't inflict much additional cost on the customer. If in
doubt, I brought the customer into the decision making process. I was
never adversely publicized on TV, nor was I investigated by the Better
Business Bureau nor Consumer Affairs. I never felt guilty. Your mileage
It's your choice to make. The one piece of advice I can give you is if
you decide to shotgun, be sure you're doing it to increase
productivity. Be sure you never do it to pad a repair bill or cover up
for diagnostic ineptitude. Be sure that any added cost to the customer
is minor when compared to the entire bill.
From an ethical viewpoint, ask yourself what you'd do if the equipment
belonged to your mother, and she was paying you.
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