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Troubleshooting CD Players

dr*audio said:
So now we know that the part that is loading down the reset line is in the lefthand part of the circuit.
1. Reinstall both jumpers.
2. Install a 1K resistor in place of the jumper near R314, and in place of the jumper below D907.
3. measure the voltage on both sides of the above resistors (just denote them by right and left side) as well as R230 and R360.
View attachment 2963118
Click to expand...
After replacing jumper wires for 1K resistors:

Near R314 left=1.73v right=4.88v
Below D907 Left=4.88v Right=4.88v
R230 Left=4.88v Right=4.88v
I could not find R360, maybe you meant R316 Left=4.88v Right=4.88v
 
"Near R314 left=1.73v right=4.88v" This is the branch drawing the current.
1. Do you understand what we are doing here and why?
2. Reinstall the jumpers.
3. Replace the jumper marked RST with a 1K resistor.
4. Measure the voltage on both sides of R313.
5. Measure the voltage on both sides of the RST 1K resistor, Top and Bottom.
 
I think I understand, Are we isolating the side drawing the current in the reset line by adding the resistors? Kind of squeezing the low voltage side towards the culprit?


1K resistor in place of jumper:

1K Resistor Top= 1.74v. Bottom = 4.89v
R313 left = 4.88v right = 4.88v
 
calavera68 said:
I think I understand, Are we isolating the side drawing the current in the reset line by adding the resistors? Kind of squeezing the low voltage side towards the culprit?


1K resistor in place of jumper:

1K Resistor Top= 1.74v. Bottom = 4.89v
R313 left = 4.88v right = 4.88v
Click to expand...
I think you have top and bottom reversed?
1692548209409.png
 
calavera68 said:
After replacing jumper with 1K resistor:

Top = 2.064v Bottom = 2.064v
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Excellent. Now unplug CN303 and measure again on both sides of the resistor.
Since the voltage is the same on both sides of the resistor we know that current is not flowing through the resistor to that part of the circuit, because of Ohm's Law; E = I X R Where E is voltage, I is current and R is resistance. So if you have 0V dropped across a resistor you know there is 0 Amps of current, or close to 0.
So we know, because of the layout, that the current has to be going through CN303 to the other board, but we must verify by unplugging the connector.
 
calavera68 said:
After removing connector:

Top = 4.99v Bottom = 4.99v

Also tray opens and closes and shows no disc
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OK! Now:
1. Reinstall the jumper and CN303.
2. The reset line connects to CN204 pin 6 on the other board. From there it splits in 2.
3. Replace the jumper under R212 with a 1K and measure voltage Right and Left.
 
dr*audio said:
OK! Now:
1. Reinstall the jumper and CN303.
2. The reset line connects to CN204 pin 6 on the other board. From there it splits in 2.
3. Replace the jumper under R212 with a 1K and measure voltage Right and Left.
Click to expand...
As soon as I removed the bottom cover to work on the audio board and follow your instructions I found the problem. I missed trimming the positive lead of capacitor C418 and it was shorting out with the bottom cover. I apologize for all the time you wasted helping me out troubleshoot this. What a rookie mistake! I corrected my mistake and connected everything and it works OK.
I really appreciate you taking your time to help me.
 
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1692562858088.png
calavera68 said:
As soon as I removed the bottom cover to work on the audio board and follow your instructions I found the problem. I missed trimming the positive lead of capacitor C418 and it was shorting out with the bottom cover. I apologize for all the time you wasted helping me out troubleshoot this. What a rookie mistake! I corrected my mistake and connected everything and it works OK.
I really appreciate you taking your time to help me.
Click to expand...
No, none of us have ever done that! LOL! Glad to have helped.
 
Hello everyone. For Dr audio and others, I have a TEAC CD player, CD P1120 with a sprayed pickup focus magnet. I got a new pick up (NOS) with mechanism in a store, the Sanyo SF-P101N 5/8. I know that this issue was already discussed at the beginning but my confusion is that being a new part of an old manufacture, I did not expect to have problems. Remove bead of safety solder, lens does focus but puck won't spin, only sees a few short pulses but never starts to spin, had to supplement rubber seats because puck was slowing down, now free moving but it doesn't rotate. Any ideas?
 
Xavirom said:
Hello everyone. For Dr audio and others, I have a TEAC CD player, CD P1120 with a sprayed pickup focus magnet. I got a new pick up (NOS) with mechanism in a store, the Sanyo SF-P101N 5/8. I know that this issue was already discussed at the beginning but my confusion is that being a new part of an old manufacture, I did not expect to have problems. Remove bead of safety solder, lens does focus but puck won't spin, only sees a few short pulses but never starts to spin, had to supplement rubber seats because puck was slowing down, now free moving but it doesn't rotate. Any ideas?
Click to expand...
Sounds like it isn't achieving focus lock. Where did you get the new pickup? I suspect that the pickup is bad or the original pickup was ok and something else is wrong with the player. Did it do the same thing before you changed the pickup?
 
In the original pickup, one of the focus field magnets was sprayed, where the focus coils are and it was all stuck, there was no movement of the lens, the machine did nothing with this pickup
 
Xavirom said:
I meant smashed, little bits stuck together. Sorry, google traslator, my english is very, very bad:confused:
Click to expand...
So, where did you get the replacement pickup? I suspect it is bad. The only reliable source I have found for laser pickups is Liberty Electronics on e-bay.
 
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