Has anyone repaired a power supply in a Panasonic FS200 VCR?

[coopermc]

Hi, My Panasonic VCR Type FS200 has developed a fault after many years of good service. The display is very weak and there is hardly any life in the machine.
I suspect the power supply module is at fault and am trying to figure out how to remove it.
Can anyone advise on the repair and how to remove the module please?
Thank you.

 

[kellys_eye]

. The display is very weak

Vacuum fluorescent? It happens with age and short of replacement there is little you can do about it.

 

[debe]

If theres hardly any life in the machine, check the voltages from the power supply. Probably needs all the electrolytic capacitors replaced in the power supply. Fairly common fault in older machines. Probably why the display is weak. Use low ESR & 105 degree C capacitors.

 

[dave9]

You'll need new belts, new rubber rollers, new PSU capacitors, new vacuum tube display, to lube all moving parts, demagnetize the heads, and possibly more to make it worth the bother.

What do you mean "trying to figure out how to remove it"? It's a circuit board held down with screws most likely, and depending on factory assembly sequence could require pulling a few other things out of the way first.

If you have valuable tapes that you need to convert to digital, I would get a new unit to do so, in order to preserve what little viewing quality that might remain at this point.

 

[73's de Edd]

Sir coopermc . . . . .

That's being the VERY top of the line PUNYSONIC machine of that vintage . . . . . WITH SVHS capability .

I have pre researched it for you. It has a little dedicated power supply just for that display and if its 2 output voltages decrease, the heater voltage or the grid displays negative polarity voltage, that will / can cause display dimming.
I also gave you the location of the YELLOW Circuit Board Assembly , which seems to be on very top and that cluster of boards must pivot and lift up after a couple of screws are removed.

Then you locate the YELLOW designated Service Pack board.
Note that all of that SPECIFIC boards parts will be using a 1700 series parts numbering.
Now find that labeled connector PS2503 on the board and use DVM in DC voltage mode and test with meter BLACK ground wire on pin 20 and confirm that meter RED wire is reading:
Minus 20 VDC on pin 29,
Minus 29.9 on pin 28
Minus 29.7 on pin 27
and then, see if there is a final approximate 10V between pins 29 to 28 ( Could read of either polarity.)

SCHEMATIC AND BOARD LAYOUT SNIPPET . . . . .



73's de Edd
.....

 

[coopermc]

Sir coopermc . . . . .

That's being the VERY top of the line PUNYSONIC machine of that vintage . . . . . WITH SVHS capability .

I have pre researched it for you. It has a little dedicated power supply just for that display and if its 2 output voltages decrease, the heater voltage or the grid displays negative polarity voltage, that will / can cause display dimming.
I also gave you the location of the YELLOW Circuit Board Assembly , which seems to be on very top and that cluster of boards must pivot and lift up after a couple of screws are removed.

Then you locate the YELLOW designated Service Pack board.
Note that all of that SPECIFIC boards parts will be using a 1700 series parts numbering.
Now find that labeled connector PS2503 on the board and use DVM in DC voltage mode and test with meter BLACK ground wire on pin 20 and confirm that meter RED wire is reading:
Minus 20 VDC on pin 29,
Minus 29.9 on pin 28
Minus 29.7 on pin 27
and then, see if there is a final approximate 10V between pins 29 to 28 ( Could read of either polarity.)

SCHEMATIC AND BOARD LAYOUT SNIPPET . . . . .

View attachment 43350

73's de Edd
.....

Thank you all for your helpful comments, It is not just the display that is weak but the whole machine is not responding to controls therefore it is most likely to be the power supply.
I intend to replace the capacitors for a start once I have managed to remove the psu module. I am gradually getting there.
Thanks very much for the diagram as I do not have a service manual.Doi you have one for the power supply module?
I know I should perhaps discard the VCR for another, I have three more VCR's but I like to get things working again which is very satisfying if I succeed and as one of you mentioned is was the top of the range at the time and it is the one I use most..
I attach photos of the VCR interior and the psu.

Thanks for your help.
Kind regards,
coopermc