Monday, July 25, 2011

PHILIPS 37PF9431D dead, power board 310432838621 not producing output voltage

Coppell TV Repair for long offers a repair service for the above mentioned power board, but today I've got a board with a problem that I have not seen before so I decided to share it so that those blog followers who wouldn't anyway pay for a service at least get a chance of doing it right by themselves :-)

Symptom: When connected to power, the board clicks periodically about once every second - not a relay click, but an electric click as of a toroid on overdrive only more quite and nicer. Like it's trying to start and failing.

Problem: it turned out transistor 7006 had failed. Drain-Source was shorted and so the transistor had to be replaced. This is the beast in reference:

It is STP15NK50ZFP SuperMESH MOSFET  - 500V / 14A - and since we couldn't find one handy we used a substitute replacement.

Here is how it looked after the replacement:

Note the insulation barrier behind the replacement - if you do something like that you will need to have one too since the original is in plastic TO-220 corpus whereas the replacement is in TO-247 has metal back electrically connected to the drain (or source, whatever).

We checked for other damages on the board and when we couldn't find any we connected to power and voila, it worked like a charm!

If you happen to have the same problem and can't find the appropriate replacement, below is a chance to get what we used at what we call reasonable price (especially considering you've got the whole solution laid in front of you):

Tuesday, July 5, 2011

How to solve support problems and avoid alienating vendors

The following is an unchanged message from our mailbox:

Dear Seller!
I'm running respected and responsible Business, where I can't take "used" or "rebuilt" IC chips(what is complete nonsence) for my Customer's repair jobs! Therefore, I need 2 chips replaced(mandatory) for the new ones! Not the way you treat my entity! One IC was brand new and legidemate, second one was used, with traces of "chiseling" out of heat sink and puncture marks. Still, I showed those 2 to my Customer, before instalationin his Y-sustainer module. He, also noticed that second one was "used". He agreed to try them both, as long as they work in tandem for a while. Yes, those 2 worked for a duration of 10 minutes with TV set completely operable. Then, of course the "used one" gave up with a click and the board went inoperable. You Must know, I can't replace just one IC, but both of the at the time! Why didn't you send me 2 new ones from the beginning? thinking: asshole will eat a s...t! Just get back you reputation, before it's too late, and send me 2 NEW ones now!

- algre1

The author is making a number of mistakes that I have come to realize over time I myself do when being in similar situation. Affected, I point all my energy towards a stupid/lame/idiotic counterpart - be it a telecom, bank or my local HOA - and then wonder why not only it didn't solve my problem, but often actually made it worse.

Over time, I learned that mistakes happen everywhere and I can't stop that from happening. I can only handle it in a way that doesn't disrupt my lifestyle significantly and helps me walk out faster and easier , even if I can't resolve it to the best of my liking.

So here it is, hoping it will help a poor customer avoid having to send an email like the above and maybe thinking (certainly incorrectly!) that they've "squared" the stupid/lame/idiotic vendor right on the spot:
1. Keep your cool!
When emotionally lifted, one tends to do a lot of things that only damage their own position - using bad language (never mind bad grammar), mixing facts and assumptions, being overly demanding in a situation that requires diplomacy to solve, taking offensive stand and thus causing anger in response...and God knows only what else.

Napoleon is said to have counted to 10 before giving a response to anything that angered him.

Think you are better than Napoleon?
2. Stick to the facts, not claims or assumptions
For example, claiming that you "are running a respected and reasonable Business" is fine, unless trying to impress it on someone who has a public record of doing just that (say over 2000 eBay customers with over 99% positive ratings) and you actually do not. You may be a respected and reasonable Business, but with a public profile of 7 transactions there is nothing behind your claim to back it up.
That matters to people.

Even worse is wearing your vendor's hat and trying to think on their behalf like illustrated above: "
thinking: asshole will eat a s...t!". 

Not everyone thinks as you think. Some of us even have a different vocabulary altogether!

And there are always at least two completely different explanations to everything that may have happened...looking for them rather than wearing the opposite party's hat and continuing to build to your own position is not going to help you.
3.  Communicate, do not demand
A direct consequence from the fact that there are at least two completely different explanations to every problem is that it is theoretically possible for the problem to have been in you in the first place. 
Whether you like to admit it or not it is always a possibility.

This is not the best example for it since it is likely that customer above was right that one of the ICs they received may have been bad, but I've blogged before about how people tend to make incorrect conclusions only to justify their own thesis.

In either case, if you want to achieve optimal result you'll be better off working under the assumption that a problem may have been caused by either side.

Certainly better than to take a one-sided stand and alienate the very people you're trying to work out a solution for yourself with.

4.  Take responsibility for your own actions
If you received something - in this case an IC - that you consider bad, then why did not act immediately and did not call the vendor?! Why instead you asked your own customer (?!) what to do - if he knew he would not have been your customer to start with.

Perhaps the following in the original listing somehow pushed you off your way:

"Please make sure to test the IC you receive before you put it on a board! We try our best to pre-screen them here and catch some problems, but ultimately you will help yourself and help us if you run a few quick checks before you spend time soldering the IC on the board."

Frankly, I think most of the customer's anger comes from the fact that they did not listen to the advice, took an action against their better judgement and are now facing the consequences of that very own action.

Granted, I'd be pissed off too when I receive something that's not what it is supposed to be, but if I try and use it against the warning and it naturally fails me I am rather certain I'd be equally mad at the vendor and myself for allowing to get into such a situation in the first place.

5. Recognize the simple fact that problems happen everywhereNothing is perfect and problems happen all the time. In any business, in any activity.
If you think your own business is perfect perhaps the first thing to do is force yourself to realize that it isn't.
Nothing is.
When a Bad Thing happens you're way better off asking yourself what's the optimal way to fix it than who is to blame, because often there is nobody actually to blame.
You may have received a bad part, but that doesn't mean your vendor put it there on purpose.

Working under that assumption is as wrong as claiming your Business is very respectable when there certainly are customers - if you are any Business at all - who surely don't think so high of you. There always are.

We've got the same blames from customers who received perfectly looking ICs. They weren't picking on the look, they were just complaining that the parts burst as soon as you power them on.
Sometimes they would have been correct and the parts would have indeed been bad and other times - without a doubt since we do repairs too - it would be something else on the board that would cause it.

Either way, building up a conspiracy theory where the vendor is trying to cheat on you - YOU of all! - is flat out immature, unless you've already given that vendor something to cause them cast trouble upon you.

As almost always, there's a simple and efficient explanation for the trouble, which does not at all require drama and conflict: there may have been a faulty product and vendor may have overlooked it. it's only normal and most vendors actually actively warn you for such a possibility as indicated above:

"Please make sure to test the IC you receive before you put it on a board! We try our best to pre-screen them here and catch some problems, but ultimately you will help yourself and help us if you run a few quick checks before you spend time soldering the IC on the board."

Your own day and the day of people around you would be so much better if you manage to stay cool and try to resolve a problem working with someone rather than trying to take a command and enforce your view and solution on others!

Sometimes you may get temporarily what you look for, but with this attitude and approach you're certain to ruin your life in the long run. 
It's a vicious cycle and it gets worse and worse as you keep discovering more and more enemies as the world inevitably hits you with more and more problems.
I guess that's why Vicodine and drinking are gaining traction all the time :-)
Isn't it so much easier to just say 
Hello, I have a problem with the parts I received from you. One of them looks like it has been used, can I please send it back for exchange/refund as per your own policy?

Of course not everyone is smart/brave/strong enough for a two-liner like that.

Luckily, most of the buyers still are and that is a fact, not a belief.

If it wasn't we wouldn't have been in business.

To set the record straight, here is the response I sent to the above letter:

"You know, I believe your story and I am sorry to hear about your troubles.

What I will do is assume that the problem is on our end, apologize for your experience and give you 100% refund on your order.

I will not offer you working parts for two reasons: first, because the original pair that you had received has come from the same box that everyone else receives parts from; you don't seem to believe that story and it's your right, but I happen to be in the position to operate based on facts, not beliefs, so if anything I certainly can make a decision easier than you do. We may not have checked the IC, that's completely possible, but that's about it and to make sure it won't happen again I am just giving you the opportunity to choose someone who can do better job for you.

Second, I just can't accept staying in a business with someone who can treat me the way you do.
Service repairs business is based on negative experiences and is tough enough as it is; inability to behave in the face of yet another problem is more than a strong indication for me to want off.

Not sure it will get through properly, but in a nutshell that's what it is: we are sorry if we have made a mistake, but those mistakes do happen, they are not purposeful and we are handling them the best we can.

In this case, we will take the complete loss and we will also take the possibility of you deciding it's all our fault and making sure we get our negative coverage for it.

We can't and won't do anything to stop you from doing that.

We just make sure that we've done the best we could for a customer and then for us to stay out of future trouble.
- coppelltvrepair"

I would not be surprised if case develops further, but at this point the only thing I really wished to say was that I am always sorry seeing how the concept of "competition" actually leads to spoiling customers by being forced to give them anything they want or else.

In long run it works against those very customers and this is something that every American is now feeling and is about to feel much more as the economic crisis unfolds further.