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Old 19th July 2008, 06:50 PM   #21
anatech is offline anatech  Canada
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Hi Mooly,
Howdy!

I agree. I think the faults have become magnified and we are now dealing with more than one fault now. Your idea to test the laser circuit is a good one.

There is little hope of figuring this out over the internet. The unit needs to be in front of another set of eyes. A common problem when troubleshooting something that has "you" stuck.

Hi fastvideo,
You have two options I think. One is to leave the unit aside for a week or so, then approach it as a new case. Imagine it's been to another shop first. Then you start from square one and forget everything you think you know about it. Keep an open mind and try not to focus too quickly. The last option would be to have another good audio technician look at this on their own bench.

-Chris
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Old 20th July 2008, 02:38 AM   #22
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Quote:
Originally posted by Mooly
Hi,
I do know you will kick yourself when you find the fault. The laser has to light first whether or not there is any other problem.
Can I ask, did the player just fail "naturally" in use or has it a history

Edit, Have looked again at the data sheet just to confirm this is a totally "analogue device" -- no data lines, clock pulses, I2C --- anything. It's got to work as it is, nothing external can influence it. Pin 19 is active high meaning it should be tied to 5 volts to permanently enable the laser. It's has to work -- it's something silly this !!!
Just wondering where is the 16mhz signal coming from with the working sony.
I got this unit from a store which I am as their repair technician now as a scrap that the old tech could not fix it. It is very well make and have HDCD function with it, well worth for me to spend the time to get it fix.


Quote:
Originally posted by anatech

There is little hope of figuring this out over the internet. The unit needs to be in front of another set of eyes. A common problem when troubleshooting something that has "you" stuck.

Hi fastvideo,
You have two options I think. One is to leave the unit aside for a week or so, then approach it as a new case. Imagine it's been to another shop first. Then you start from square one and forget everything you think you know about it. Keep an open mind and try not to focus too quickly. The last option would be to have another good audio technician look at this on their own bench.

-Chris
I have this unit over 9 months. This is my 6 attempt to fix it. No rush but really need others fresh opinion.
Will keep this up with the working sony to campare.

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Old 20th July 2008, 03:31 AM   #23
anatech is offline anatech  Canada
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Hi fastvideo,
Quote:
Just wondering where is the 16mhz signal coming from with the working sony.
Clock signal.
Quote:
This is my 6 attempt to fix it.
You are repeating the same errors in that case. Re-read the responses you have in this thread. You should find the answer in there somewhere. Note that most of what I have said addresses the act of troubleshooting.

Fresh eyes or a fresh approach is required. I wish you luck either way.

-Chris
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Old 20th July 2008, 06:59 AM   #24
Mooly is offline Mooly  United Kingdom
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Well -- final thoughts -- this is what I would do. Solder a good tag on the ground around the IC so you can permanently connect your meter and 'scope -- there is nothing worse than having one eye on the DVM and trying to poke around with two hands.
Go around EVERY pin on that IC. Does each pin electrically go where it should -- don't just look - measure on low ohms -- could be a hairline crack etc. And measure the volts on each pin, not with a DVM use the 'scope on DC, it's much more revealing showing noise etc. Resolder that shorting link and measure each track on ohms from the pickup to the IC.
If you are still getting nowhere, REMOVE the PNP transistor and solder a 10k (anything between 4k7 and 100k ) between base and emmiter. Now measure again pin 1 both with pin 19 held high and again with it re-connected normally during focus search.
Is it still stuck high ? Lift pin 1 at the IC if so and measure again on the floating pin ? Just had a thought -- connect LED and resistor from collector to ground anyway during testing. Use a bright LED and say a 2K2. That shouldn't upset anything. Remember to unsolder the link again.

Keep us all updated
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Old 20th July 2008, 06:12 PM   #25
anatech is offline anatech  Canada
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Hi Mooly,
One thing to add to that. Take notes at each step fastvideo.

-Chris
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