Please Suggest!

Individual PC boards? What is this, the first DVD player in a VME frame?

What are you trying to do? You'll learn more about how DVD players work by googling around than by blindly poking around a DVD player.

For the DVD player to work, every waveform is required.

As Phill Allison would say, groper alert.

Working on it means repairing it???

Yea, don't do it if you ever expect to use it again.

The proper syntax of posted questions is required generally.

For people who know how to use them.

Luhan ;(

The only meaningfull wave form measurements are for the power supply.

Don't touch the 220V AC or 300V DC.

All of them.

DVDs are digital. You would be better off with Logic Analyser, but still useless for mpeg decodings.

Sorry, but like some posters here, the very questions you ask indicate that you are trying to do something far beyond your knowledge. Also, that you probably have no idea what you are doing.

There is no way to give a technical answer in such a situation.

You may try posting to sci.electronics.basics ...

Luhan

How did you manage to get a job without knowing how to use a basic piece of test equipment?

You don't seem to have the skills for the simplest electronic job. And certainly not for development work.

Which company are you working for, and which country?

He's a good talker! :) I know from first hand experience when i interviewed a person to perform a break down electricians job. I'm usually thorough in interviewing people for those kind of jobs. I normally run them through a list of questions about drives, motors, controllers of various sorts. I must say, this person we hired not only fooled my boss which has an Electrical Degree and on job experience, but he also fooled me in the electronics area. My mistake was, I didn't actually request for him to show me something. His prior job that he held, to me was enough, along with how he was answering the questions sounded like he had more then enough confidence to perform the task we expected of him. As it stands now, 4 months down the road. I have concluded that he is the biggest bull shit artist and is very good at it. I have learned from this experience from now on, an on sight interview at the equipment that we expect the person to grasp is a must along with some basic electrical and electronic paper questions.

I'm sure others here have had similar experience as I ?

--
"I\'m never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.

Are you saying that I am good for nothing but only good at talking? I did not lie to my engineer in interviews, nor did I pretend to be a specialist in hands on electrionics. As I have said, our job nauture is more on documentation than hands on and they really needed someone who understands schematics and I had enough experience on schematic and printed circuit board drawing in Protel although I did not have enough experience in handling ALIVE circuits in which electrons used to go to and fro! My aeniors really know what kind of guy they have to choose as their temp staff. How do you feel humiliating a begineer? Do you feel good? Then it is OK. Fine, you can say what ever you wish to say. And more over, I have read "XYZ of Oscilloscopes" by Tektronix these days. And I came to understand the concept of Trigger systems was to stabilize a repititive waveform, creating a clear picture of signal. As I said earlier, I know I have to push trigger button sometimes but I just could not remember what is the reason behind all this. Now from the discussions in this forum, I learned that

1. I should at first need to ask my seniors about things I need to know.
2. Then I should read guide lines and try myself first rather than being a lazy bone, not reading what I should read thoroughly, but just submit some questions and get inintiave form the answers in the forum, thank you all for the answers you have given to me in this three months period, I have learned a lot from the forum these days.
3. Then again and again I need to study until the questions that needed to be asked in the forum gets clear to me. and 4. Then submit

OK?

And please tell me something about the trigger system if somebody is patient enough to answer my questions. :)

I understand that it is a system usually before the sweep generator in the horizontal system.

Still I do not understand this, written in the XYZ of oscilloscope:

" Triggering the horizontal system causes the horizontal time base to move the glowing dot across the screen from left to right within a specific time interval"

Please explain to me about it more clearly, and please show me some links explaining more about the trigger system with appropriate circuit diagrams.

Thank you very much for you motivations!

I will not stop learning until I understand the whole system of oscilloscope inside out, no matter what it takes.

:) My be you would say again I am a good talker.

Please wait and see how a talker alters the saying: " Talkers are not good done!"

:) Jamie wrote:

Late at night, by candle light, "Myauk" penned this immortal opus:

I suppose you already have the scope. Get yourself an audio generator and an old AM radio with schematic. The AG can be one of those PC based ones so you can supplement it with a MP3 player.

Set the AG for some well defined and easy to understand wave forms, play around with the scope settings until you see something that fits the wave form. Play around with the AG settings and see what happens with the display. After a while you'll get a feel for how the settings fit together. That can take a bit of time, from minutes to days to weeks to years, some people never get it.

Next step is to turn on the MP3 player and look at the output. This part is mostly for entertainment but that's what many real signals look like.

Once you have that down open up the radio, study the schematic to find the "diagnostic points" and scope them. You do know how an AM radio works, don't you? Confirm that the wave forms really look what the text books claim.

- YD.

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Remove HAT if replying by mail.

I just need that kind of encouragement. :)

Yes, sure, I am working on it.

And I am reading XYZ of Oscilloscopes from

and came to understand about Analogue, Digitat Storage, Digital Phosphor, and Digital Sampling types. I cannot use the devices you asked me to use because I do not have the oscilloscope at home but I am using it to do some waveform measurements at my office. Sicne I did documentation mostly, when it is time for me to do the wave form measurement for the first time in Singapore, I felt I forgot everything with my practical things. Being in the "International Environment", I am really afraid of doing what I am not supposed to do because as I have said I came from the undeveloped country.

This is the reason why I am submitting the question. Yes I try to test the oscilloscope in several different ways until I understand it well as you said.

The oscilloscope I used here is TDS 744A Tektronix.

And still I found something I do not understand while measuring the crystal clock signal of the Multistand Sound Processor ( Sound Audio Demodulator).

I found a sine wave there, and I measured the frequency of it but it said Hz waveform does not cross the reference!

I would like to know why.

Regards

P.S Well I talked much aga> Late at night, by candle light, "Myauk"

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Learn to bottom post.

From:

Late at night, by candle light, "Myauk" penned this immortal opus:

Set the reference at about the midpoint of the waveform. I don't know the scope your using but there must be a marker somewhere. The scope counts the times the waveform goes above and below the reference. It really should have said zero, so there may be something else going on.

If you tested across the crystal itself it's normal to see a sinewave, the circuitry squares it up before passing it along.

You have a lot of twiddling settings and knobs to do yet. Don't give up, reading a scope takes practice.

- YD.

--
Remove HAT if replying by mail.

Make sure you have at least 2 or 3 full cycles of the signal displayed on the screen, and make the waveform at least half the height of the screen.

Also, on a mullti-channel scope, make sure the scope is measuring the channel you want it to!

--
Peter Bennett, VE7CEI  
peterbb4 (at) interchange.ubc.ca  

Thank you, Finally, I learned how to use the oscillope before my supervisor came back. I did not bother him much but you people in this group. Now I am printing waveforms well and it is cool! Regards