Hey folks,
I'm getting way different AC voltage readings than the schematic calls for. Sorry I don't have the ability to post one page of a pdf here, but the manual (with schematics at the end) can be found here: Free Otari Schematics and Manuals - from AnalogRules.com and AudioSchematics.com under "MX 5050 B II Schematics"
Anyway, the machine is completely black (not dead because I can still read these voltages on the power supply, but black with no function whatsoever) It was working fine until I accidentally left a socket wrench on the end of the solenoid that (I think physically) prevented a fast forward function (or else shorted something) and burned the 100 ohm resistor R712. I replaced the resistor, but I got problems. At first the machine would fast forward and rewind but not play. Then it eventually went black.
In investigating, I found the following AC voltages at the connector labeled "U" which appear to be power transformer secondaries, but they're way off. I'm wondering if I damaged the power transformer?
Schematic AC Voltages:
U1 0V
U2 19.5V
U3 19.5V
U4 19V
U5 0V
U6 0V
U7 21V
U8 0V
U9 8.5V
U10 27V
U11 0V
U12 26V
My AC readings:
U1 gnd
U2 21V
U3 21V
U4 10.4V
U5 11.9V
U6 11.8V
U7 10.8V
U8 .2V
U9 9V
U10 14.7V
U11 14.3V
U12 18.3V
P.S.
I should mention as well, I measured all the fuses and found a blown one at FS703.
I also measured ohms across the diodes (in circuit) and I'm generally getting from 105K-120K EXCEPT in the case of D705, which is only around 3K.
???
I'm getting way different AC voltage readings than the schematic calls for. Sorry I don't have the ability to post one page of a pdf here, but the manual (with schematics at the end) can be found here: Free Otari Schematics and Manuals - from AnalogRules.com and AudioSchematics.com under "MX 5050 B II Schematics"
Anyway, the machine is completely black (not dead because I can still read these voltages on the power supply, but black with no function whatsoever) It was working fine until I accidentally left a socket wrench on the end of the solenoid that (I think physically) prevented a fast forward function (or else shorted something) and burned the 100 ohm resistor R712. I replaced the resistor, but I got problems. At first the machine would fast forward and rewind but not play. Then it eventually went black.
In investigating, I found the following AC voltages at the connector labeled "U" which appear to be power transformer secondaries, but they're way off. I'm wondering if I damaged the power transformer?
Schematic AC Voltages:
U1 0V
U2 19.5V
U3 19.5V
U4 19V
U5 0V
U6 0V
U7 21V
U8 0V
U9 8.5V
U10 27V
U11 0V
U12 26V
My AC readings:
U1 gnd
U2 21V
U3 21V
U4 10.4V
U5 11.9V
U6 11.8V
U7 10.8V
U8 .2V
U9 9V
U10 14.7V
U11 14.3V
U12 18.3V
P.S.
I should mention as well, I measured all the fuses and found a blown one at FS703.
I also measured ohms across the diodes (in circuit) and I'm generally getting from 105K-120K EXCEPT in the case of D705, which is only around 3K.
???
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