Well, I have new results
I connected the potentiometer U17 as indicated in Seankane thread, I have also removed R31 and R35
No MOSFET transistor output on the motherboard
When connecting, and testing, the pins on the motherboard of the first group of eight MOSFETs, -9.70v. and 9.68 v. respectively when turning the knob from right to left.
But, to do the same with the other group of eight MOSFETs, and turn the knob, -9.92 v only appear as shown in photo
Which makes me suspect that there is any fault in what belongs to that section, but where? Any hints?
I will order more parts ... (LM6171, HCPL2211, MIC4420, etc. ...)
I connected the potentiometer U17 as indicated in Seankane thread, I have also removed R31 and R35
No MOSFET transistor output on the motherboard
When connecting, and testing, the pins on the motherboard of the first group of eight MOSFETs, -9.70v. and 9.68 v. respectively when turning the knob from right to left.
But, to do the same with the other group of eight MOSFETs, and turn the knob, -9.92 v only appear as shown in photo
Which makes me suspect that there is any fault in what belongs to that section, but where? Any hints?
I will order more parts ... (LM6171, HCPL2211, MIC4420, etc. ...)
Attachments
Well, I'm here again
I have checked, U5, U6, U7, U8, U9, U10 and U15,
Turning the potentiometer all well regulated, volts positive and negative volt, at its inputs and its outputs, except the output of U15 (pin 7) and the output of U6 (pin 5) to give - 9.70 v always
I'm surprised that the latter are wrong, I have changed recently, is it possible that you are wrong? IC should I check some more? (TL 074, LM6172IM, .....)
I have checked, U5, U6, U7, U8, U9, U10 and U15,
Turning the potentiometer all well regulated, volts positive and negative volt, at its inputs and its outputs, except the output of U15 (pin 7) and the output of U6 (pin 5) to give - 9.70 v always
I'm surprised that the latter are wrong, I have changed recently, is it possible that you are wrong? IC should I check some more? (TL 074, LM6172IM, .....)
Hey, Perry, what do you think? the gould or the hameg?
http://www.ebay.es/itm/180864467380?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
http://www.ebay.es/itm/120897679647?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
http://www.ebay.es/itm/180864467380?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
http://www.ebay.es/itm/120897679647?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
Sorry that I didn't see #103 earlier.
Confirm that the voltage measured directly across pins 2 and 3 of U15 are switching from 1.1v to -0.6v when you go from one extreme to the other with the potentiometer.
If that's right and the output of the opto-coupler isn't swinging to plus and minus 9v, the opto-coupler is defective. I'm assuming that the opto-coupler has approximately 18v across pins 5 and 8.
The scope with the sine wave locked on the display seems less likely to be defective. The one with only two straight traces could have several problems. Either one would should be good enough they are both in good working order.
Confirm that the voltage measured directly across pins 2 and 3 of U15 are switching from 1.1v to -0.6v when you go from one extreme to the other with the potentiometer.
If that's right and the output of the opto-coupler isn't swinging to plus and minus 9v, the opto-coupler is defective. I'm assuming that the opto-coupler has approximately 18v across pins 5 and 8.
The scope with the sine wave locked on the display seems less likely to be defective. The one with only two straight traces could have several problems. Either one would should be good enough they are both in good working order.
Perry quiet, do not feel, I know I'm patient and wait
I've done the checks that have told me and the voltage measured directly across pins 2 and 3 of the U15 is changing from 1.4V up to -0.68 V when going from one extreme to another with a potentiometer.
Between pins 5 and 8 is 19V
And on pin 7, there is always -9.70 V, while moving from one extreme to another with potentiometer
So I'll order a HCPL2211 (I heard that this IC, it is delicate to handle, is it true?)
Regarding the scope, most likely, I do, is to follow his wise advice, and try to stay with the Gould Ø300
Thanks again, Perry, and when you receive the parts, tell what happens.
I've done the checks that have told me and the voltage measured directly across pins 2 and 3 of the U15 is changing from 1.4V up to -0.68 V when going from one extreme to another with a potentiometer.
Between pins 5 and 8 is 19V
And on pin 7, there is always -9.70 V, while moving from one extreme to another with potentiometer
So I'll order a HCPL2211 (I heard that this IC, it is delicate to handle, is it true?)
Regarding the scope, most likely, I do, is to follow his wise advice, and try to stay with the Gould Ø300
Thanks again, Perry, and when you receive the parts, tell what happens.
Well, I got the A2211 (U15)
And, check voltages, I noticed that when you turn the potentiometer back and forth in the output of this IC, I have, -9.70 v and 7.28v is this correct?
For a comparison with the other IC (U9) I have, -9.90 v and 10.28v Do these tensions should be more similar (7.28 and 10.28)?
¿I can ride MEHSA strip with all the mosfet?
And, check voltages, I noticed that when you turn the potentiometer back and forth in the output of this IC, I have, -9.70 v and 7.28v is this correct?
For a comparison with the other IC (U9) I have, -9.90 v and 10.28v Do these tensions should be more similar (7.28 and 10.28)?
¿I can ride MEHSA strip with all the mosfet?
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