Positive. 1000 percent positive. I need more than just an hour a day on this in order to get it sorted . Although its a pain it's quite interesting
The fuses that are failing is fuse 4 and fuse 2. They have something to do with tray laser and power off/on. When I left it the day before it was normal, but the GF had company, so they might have tried to play it.
oops!
Check we are using the same manual. Mine says F2 is on one phase of a centre-tapped 17vac+17vac supply. F4 is on the opposite phase of a centre-tapped 11vac+11vac supply. F3 and F1, respectively, are their partners on the other phases.
Check the transformer by unplugging J2 and measuring the ac voltage between each fuseholder and the brown centre-tap connection.
Assuming ac voltages are good and fuses don't blow with J2 unplugged, the question then is why are the fuses of only one phase of each supply blowing? Shorts to ground after a bridge rectifier should blow both phases, whereas shorts between phases should blow only one phase.
Assuming now that your girlfriend is innocent and that the fuses blew as a result of the cap disaster and collateral, you might still have been able to read approximately the right voltages on all voltage regulator outputs except the -17V one. However, they would have been derived from half-wave rectification because only one phase was present in each case. That should have been apparent if you also measured using the AC range on your meter, because the regulators would be dropping out and lots of ripple would be present.
Rectifier diodes and the bridge rectifier are now suspect. The regulators are current-limiting so should have protected themselves. They are 1.5A devices, so they would not have stopped the 800mA fuses from blowing. If the disaster cap failed to a short suddenly enough, the bridge rectifier and/or some of the rectifier diodes might have been damaged before the fuses had time to blow. If the 7010 failed suddenly, then that might have taken out more diodes, although I doubt it.
So, with J2 still unplugged, and looking at the board connector now, use the ohms setting on your meter to check the resistance between each of the J2 connections and ground.
It would be safer to try and find a problem without connecting the power, so take out all the fuses and leave J2 unplugged for now. That should be girlfriend-proof.
Check we are using the same manual. Mine says F2 is on one phase of a centre-tapped 17vac+17vac supply. F4 is on the opposite phase of a centre-tapped 11vac+11vac supply. F3 and F1, respectively, are their partners on the other phases.
Check the transformer by unplugging J2 and measuring the ac voltage between each fuseholder and the brown centre-tap connection.
Assuming ac voltages are good and fuses don't blow with J2 unplugged, the question then is why are the fuses of only one phase of each supply blowing? Shorts to ground after a bridge rectifier should blow both phases, whereas shorts between phases should blow only one phase.
Assuming now that your girlfriend is innocent and that the fuses blew as a result of the cap disaster and collateral, you might still have been able to read approximately the right voltages on all voltage regulator outputs except the -17V one. However, they would have been derived from half-wave rectification because only one phase was present in each case. That should have been apparent if you also measured using the AC range on your meter, because the regulators would be dropping out and lots of ripple would be present.
Rectifier diodes and the bridge rectifier are now suspect. The regulators are current-limiting so should have protected themselves. They are 1.5A devices, so they would not have stopped the 800mA fuses from blowing. If the disaster cap failed to a short suddenly enough, the bridge rectifier and/or some of the rectifier diodes might have been damaged before the fuses had time to blow. If the 7010 failed suddenly, then that might have taken out more diodes, although I doubt it.
So, with J2 still unplugged, and looking at the board connector now, use the ohms setting on your meter to check the resistance between each of the J2 connections and ground.
It would be safer to try and find a problem without connecting the power, so take out all the fuses and leave J2 unplugged for now. That should be girlfriend-proof.
F1 and F4 are blowing..I didn't have the manual with me when i wrote the reply. So that is happening. Right. The other thing that is happening is:
Try keeps opening and won't stop opening, could the switch be bad? I don't know. 😡
Also, power off and on does not respond. I checked all the diodes on the power supply and they all tested fine. I pulled one leg out of each diode and tested them, so that puts an end to the diode theory. I checked all the resistors and THEY tested to spec, perhaps (2) 47K resistors had trouble climbing to 47k and would slowly rise, but otherwise all tested fine. I have not checked the transistors, there is like 11 of em on the PCB and need to device some plan of getting to each leg without pulling them out.
As for J2 it's fine. I also tested the points between DZ1 and J2, and only place where there is continuity is where there should be.
As for the fuses( F4 AND F1,) they say SLOW BLOW, but they act like FAST BLOW.😀
Try keeps opening and won't stop opening, could the switch be bad? I don't know. 😡
Also, power off and on does not respond. I checked all the diodes on the power supply and they all tested fine. I pulled one leg out of each diode and tested them, so that puts an end to the diode theory. I checked all the resistors and THEY tested to spec, perhaps (2) 47K resistors had trouble climbing to 47k and would slowly rise, but otherwise all tested fine. I have not checked the transistors, there is like 11 of em on the PCB and need to device some plan of getting to each leg without pulling them out.
As for J2 it's fine. I also tested the points between DZ1 and J2, and only place where there is continuity is where there should be.
As for the fuses( F4 AND F1,) they say SLOW BLOW, but they act like FAST BLOW.😀
F1 and F4 makes more sense. Now check resistance from +5V regulator to ground. Ditto for -7V. Ditto for +5V-STBY. That is, pin 2 of IC5, pin 3 of IC4, and pin 2 of IC6, each to pin 1 of J2.
They should show an instantaneous low reading, but then climb to some steady reading as the caps charge up, unless there is a short, in which case the reading will remain low.
If no short is detected there, check inputs of same regulators in the same way.
Don't panic over all the operational symptoms: a missing supply voltage can explain many things. Try not to wander...take one thorough, methodical step at a time.
Resistors don't fail to a short so forget them. I can't see how any of the transistors can be a cause of blowing fuses either, so you can forget them too for the moment. The more work you do on the board, the greater the chance of introducing yet more faults.
They should show an instantaneous low reading, but then climb to some steady reading as the caps charge up, unless there is a short, in which case the reading will remain low.
If no short is detected there, check inputs of same regulators in the same way.
Don't panic over all the operational symptoms: a missing supply voltage can explain many things. Try not to wander...take one thorough, methodical step at a time.
Resistors don't fail to a short so forget them. I can't see how any of the transistors can be a cause of blowing fuses either, so you can forget them too for the moment. The more work you do on the board, the greater the chance of introducing yet more faults.
Here is the update...
On J1,
Pin10=12.35v
Pin12=-12.20v
And Q6 and Q7 measure the same.
Now it gets messy.
Readings for IC9-IC4
IC9:
-17.40v
-16.09v
IC8=
-12.32v
-11.03v
-18.15v
IC7=
18.03
10.95
12.23
IC6=
11.84V
3.82V
5.06
IC5=
11.85
3.83
5.04
IC4=
-7.11V
-5.84
-13.73
NONE OF THESE READINGS MAKE SENSE!!!!
Fuse F1 and F4 no longer blow. I assume its cause i unplugged the tray motor. That won't stop turning. I would like to put and end to that. i assume the sensor is no longer in operation or the motor has a short.
On J1,
Pin10=12.35v
Pin12=-12.20v
And Q6 and Q7 measure the same.
Now it gets messy.
Readings for IC9-IC4
IC9:
-17.40v
-16.09v
IC8=
-12.32v
-11.03v
-18.15v
IC7=
18.03
10.95
12.23
IC6=
11.84V
3.82V
5.06
IC5=
11.85
3.83
5.04
IC4=
-7.11V
-5.84
-13.73
NONE OF THESE READINGS MAKE SENSE!!!!
Fuse F1 and F4 no longer blow. I assume its cause i unplugged the tray motor. That won't stop turning. I would like to put and end to that. i assume the sensor is no longer in operation or the motor has a short.
Last edited:
Guessing which pins are which, but all those readings seem good to me.
The motor won't run if it "has a short". Neither will it blow a fuse.
The motor won't run if it "has a short". Neither will it blow a fuse.
The motor runs constantly only if the ribbon cable is plugged in. once the ribbon cable is unplugged motor behave as usual. But none of the buttons work and I can't seem to power of the player without unplugging it. Will go back at it on wednesday, as for the values they don't seem right to me, but will confirm once i measure the chips elsewhere.
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