Friday, August 31, 2012

A question about my DVD player repair guide eBook.


Gerry…
Hello. Can you tell me if the DVD repair eBook methods can be applied to CD players?

My 2005 Dodge Grand Caravan automotive CD player does not play any CD's and does not eject CD's. 

We also have a Sony AM/FM CD player. We had a power outage several months ago. Ever since then the CD player won't read any CD's.

Everything else works perfectly and I can hear the player trying to read the CD. Thanks.


Hi Gerry,
Usually the CD/VCD/DVD player are similar electronically speaking, what make them different is actually the software but the hardware is the same.

DVD player is more advanced in terms of software technology and therefore can read CD/VCD discs but CD player cannot read DVD discs.

Having said that let me say that your 2005 automotive CD player sounds like it just need service like cleaning the dust inside, also check if there is anything blocking the drawer and if there is nothing then check if the spindle motor is shorted. 

These motors have a short lifespan and I suspect is the main cause of all this. Also be sure all power connectors are not loose.

For the CD player which was hit by power surge, power surge only affect the power supply section so I suggest you open the CD player and see if the main capacitor is slightly swollen at the top. And any burnt component on the power supply side.

If the main capacitor was affected, and being the main filter capacitor then it means the output voltages will be unstable and hence the CD player can behave abnormally.

Regards Humphrey


Hello Humphrey: I can't thank you enough for responding so quickly. I appreciate the CD/DVD clarification.

My automotive CD player has been removed and is on my desk. I can see that the internal workings are clean and free from any dust.

I have tested the two small motors inside the CD player for continuity. One motor I believe drives the CD in and out of the player, the second, larger motor spins the CD. Both read .01 on the continuity reading.

Does this low reading indicate good continuity or bad? I hope to be making a bench power supply out of a converted computer power supply so I can test the entire radio at my desk.

Until then I don't know what else to do. I have not yet tackled the Sony CD player so my findings on that will come later.

Sincerely


Hi Gerry,
There you go Gerry...that motor with 0.01 ohms is dead short...it should read between 5 ohm and 20 ohms. Change it directly
Regards Humphrey

Humphrey that is good news indeed. Question though.

My very limited and basic understanding of testing continuity says that a continuity reading should be 0.00 if there is good continuity. Is that not correct? 

How did you know the readings should be between 5 ohms and 20 ohms? 

One last question. Would your eBook help me with this and the Sony issue?  Thanks again for your insight.  



Hi Gerry,
Good question...please note there is a difference between a short circuit and continuity.

Motors when tested with a meter usually can have a continuity of between 5 ohms and 20 ohms.
Now if the motor shorts...it reads very low ohms...it is like you have connected the two wires + and - together and hence the short is created.

By the way to get 0.00 ohms is not possible because even the wires have some resistance and therefore I expect some reading on your meter like 0.1 to 1 ohm.

Again you can compare the reading of that motor with the other two and you will see the difference.

Be sure you dis-connect one wire of the motor from the circuit when doing this test.

With regards to my eBook I have written it from the technician workbench point of view so most of the things I have covered are the common problem with these things and therefore can be a very good source of reference.

Regards Humphrey



4 comments:

  1. HI HUMPHREY

    thanks for your technical dialog with GERRY it is very useful
    beh

    ReplyDelete
    Replies
    1. HiBeh, Thanks for your feedback...Glad to see you here!

      Regards Humphrey

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  2. Nice to hear and reading post here.A very informative sharing technical ideas.thanks Humphrey for your untiring suppot.

    ReplyDelete
    Replies
    1. Hi Mangjose, Thanks for your positive feedback...Here at hum-tech electronics value your comments and we are committed to consistently keep this blog updated with fresh materials..

      regards Humphrey

      Delete