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
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
Mooly said:
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.
anatech said:
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.
Hi fastvideo,
Fresh eyes or a fresh approach is required. I wish you luck either way.
-Chris
Clock signal.
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
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 🙂
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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