Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to sci.electronics.repair
|
|||
|
|||
Proscan PSVR80 power supply
Looking for the schematic for just this section if possible. I am
pretty sure I have a flaky supply on one pin. The VCR would work for a while then display would blank out. Working time got shorter and shorter. |
#2
Posted to sci.electronics.repair
|
|||
|
|||
Proscan PSVR80 power supply
Does the vcr function but just the display craps out? May be specific to the
supplies to the display area. Or is the whole vcr intermittant? wrote in message ... Looking for the schematic for just this section if possible. I am pretty sure I have a flaky supply on one pin. The VCR would work for a while then display would blank out. Working time got shorter and shorter. |
#3
Posted to sci.electronics.repair
|
|||
|
|||
Proscan PSVR80 power supply
On Dec 15, 9:42 am, "AJ" wrote:
Does the vcr function but just the display craps out? May be specific to the supplies to the display area. Or is the whole vcr wrote in message ... Looking for the schematic for just this section if possible. I am pretty sure I have a flaky supply on one pin. The VCR would work for a while then display would blank out. Working time got shorter and shorter. Hi - At this point it's pretty much dead, no display or motor function. When in it's death throes, I could press a button on the control panel, it would begin the function (eject, FF, RW etc) the display would blink out WHILE it was operating, then when the operation completed, it wouldn't respond to any key presses any more. If I pulled the plug for a while, then plugged back in and left it alone, the display would work for a random amount of time before blinking out. I took out the power supply section and was probing the pins that fed everything - I came across a pin that was fluctuating between 6 and 8 volts. I followed the traces on the PCB to a patch of poorly cleaned flux and thought maybe it was allowing voltage to leak. I cleaned the flux and tested the pin again - it was hovering steady at 0.2 volts. I hooked it back into the VCR - still dead. My conclusion is that there is supposed to be voltage on that pin, but I need schematics to be sure. I guess eventually I will break down and buy a Sams copy but at this point the cost is not worth it, so I thought I would through out the question and see what happens. |
#4
Posted to sci.electronics.repair
|
|||
|
|||
Proscan PSVR80 power supply
wrote in message ... On Dec 15, 9:42 am, "AJ" wrote: Does the vcr function but just the display craps out? May be specific to the supplies to the display area. Or is the whole vcr wrote in message ... Looking for the schematic for just this section if possible. I am pretty sure I have a flaky supply on one pin. The VCR would work for a while then display would blank out. Working time got shorter and shorter. Hi - At this point it's pretty much dead, no display or motor function. When in it's death throes, I could press a button on the control panel, it would begin the function (eject, FF, RW etc) the display would blink out WHILE it was operating, then when the operation completed, it wouldn't respond to any key presses any more. If I pulled the plug for a while, then plugged back in and left it alone, the display would work for a random amount of time before blinking out. I took out the power supply section and was probing the pins that fed everything - I came across a pin that was fluctuating between 6 and 8 volts. I followed the traces on the PCB to a patch of poorly cleaned flux and thought maybe it was allowing voltage to leak. I cleaned the flux and tested the pin again - it was hovering steady at 0.2 volts. I hooked it back into the VCR - still dead. My conclusion is that there is supposed to be voltage on that pin, but I need schematics to be sure. I guess eventually I will break down and buy a Sams copy but at this point the cost is not worth it, so I thought I would through out the question and see what happens. The most likely culprit, generically speaking, is bad electrolytic caps in the power supply. Mainly but not limited to the secondary circuit. Anywhere from 10 to 1000 uF or so, there could be up to about ten of them. They should be replaced with low impedance 105 degree types - lesser quality ones may run for a while, then blow the thing up - learned that one the hard way. Switchmode type supplies are pretty critical about that sort of thing. Mark Z. |
#5
Posted to sci.electronics.repair
|
|||
|
|||
Proscan PSVR80 power supply
On Dec 16, 5:02 am, "Mark D. Zacharias"
wrote: wrote in message ... On Dec 15, 9:42 am, "AJ" wrote: Does the vcr function but just the display craps out? May be specific to the supplies to the display area. Or is the whole vcr wrote in message ... Looking for the schematic for just this section if possible. I am pretty sure I have a flaky supply on one pin. The VCR would work for a while then display would blank out. Working time got shorter and shorter. Hi - At this point it's pretty much dead, no display or motor function. When in it's death throes, I could press a button on the control panel, it would begin the function (eject, FF, RW etc) the display would blink out WHILE it was operating, then when the operation completed, it wouldn't respond to any key presses any more. If I pulled the plug for a while, then plugged back in and left it alone, the display would work for a random amount of time before blinking out. I took out the power supply section and was probing the pins that fed everything - I came across a pin that was fluctuating between 6 and 8 volts. I followed the traces on the PCB to a patch of poorly cleaned flux and thought maybe it was allowing voltage to leak. I cleaned the flux and tested the pin again - it was hovering steady at 0.2 volts. I hooked it back into the VCR - still dead. My conclusion is that there is supposed to be voltage on that pin, but I need schematics to be sure. I guess eventually I will break down and buy a Sams copy but at this point the cost is not worth it, so I thought I would through out the question and see what happens. The most likely culprit, generically speaking, is bad electrolytic caps in the power supply. Mainly but not limited to the secondary circuit. Anywhere from 10 to 1000 uF or so, there could be up to about ten of them. They should be replaced with low impedance 105 degree types - lesser quality ones may run for a while, then blow the thing up - learned that one the hard way. Switchmode type supplies are pretty critical about that sort of thing. Mark Z. Thanks for the reply, I'll give that a look. Here's when I wish I had an ESR tester... Scott |
#6
Posted to sci.electronics.repair
|
|||
|
|||
Proscan PSVR80 power supply
Bob Parker devices are still available at a very reasonable price. Google
for them. wrote in message ... On Dec 16, 5:02 am, "Mark D. Zacharias" wrote: wrote in message ... On Dec 15, 9:42 am, "AJ" wrote: Does the vcr function but just the display craps out? May be specific to the supplies to the display area. Or is the whole vcr wrote in message ... Looking for the schematic for just this section if possible. I am pretty sure I have a flaky supply on one pin. The VCR would work for a while then display would blank out. Working time got shorter and shorter. Hi - At this point it's pretty much dead, no display or motor function. When in it's death throes, I could press a button on the control panel, it would begin the function (eject, FF, RW etc) the display would blink out WHILE it was operating, then when the operation completed, it wouldn't respond to any key presses any more. If I pulled the plug for a while, then plugged back in and left it alone, the display would work for a random amount of time before blinking out. I took out the power supply section and was probing the pins that fed everything - I came across a pin that was fluctuating between 6 and 8 volts. I followed the traces on the PCB to a patch of poorly cleaned flux and thought maybe it was allowing voltage to leak. I cleaned the flux and tested the pin again - it was hovering steady at 0.2 volts. I hooked it back into the VCR - still dead. My conclusion is that there is supposed to be voltage on that pin, but I need schematics to be sure. I guess eventually I will break down and buy a Sams copy but at this point the cost is not worth it, so I thought I would through out the question and see what happens. The most likely culprit, generically speaking, is bad electrolytic caps in the power supply. Mainly but not limited to the secondary circuit. Anywhere from 10 to 1000 uF or so, there could be up to about ten of them. They should be replaced with low impedance 105 degree types - lesser quality ones may run for a while, then blow the thing up - learned that one the hard way. Switchmode type supplies are pretty critical about that sort of thing. Mark Z. Thanks for the reply, I'll give that a look. Here's when I wish I had an ESR tester... Scott |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
HP/Agilent E3632A programmable power supply has power up failure (solution) | Electronics Repair | |||
power supply heating problem [2/6] "HIGH POWER 2uS tb.jpg" (1/1) | Electronic Schematics | |||
power supply heating problem [3/6] "HIGH POWER 5uS tb.jpg" (1/1) | Electronic Schematics | |||
ATX power supply to bench supply conversion | Electronics Repair | |||
X-Box power surge - blew out switching power supply | Electronics Repair |