Need to identify diodes, Magnavox VCR model VR9550ATO1

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This is the old Panasonic type chassis that uses the removable power
supply. This is a small separate board mounted in a small ventilated
metal rectangular can which measures about 2" X 2" X 5". It is marked
"Power circuit ref. # 1000 series" , This power supply is mounted
vertically to the main board and connects with a small multi conductor
ribbon cable. There are two shorted diodes on this supply. They are
D14, a zener, and D8. I know this is a stretch but does anyone have a
schematic diagram for this model who might be kind enough to look
these up for me? I tried the distributors but they no longer have this
information. Thanks for any assistance. Lenny Stein, Barlen
Electronics.

 

[Bill S.]

[email protected]>, [email protected]
says...

There are two shorted diodes on this supply. They are
D14, a zener, and D8.

D1014 = MA2180 or RD18FB, Philips PN 5301921180
18V 1W Zener is there solely for protection - the circuit
would work fine without it under normal conditions. The fact
that it is shorted suggests that supply regulation has gone
awry. Common failures are C1015, 1000uF 16V output filter -
high ripple current is very hard on this capacitor - and C1007,
4.7uF 200V primary side snubber.

D1008 = ERB32-01 or RU2YX, Philips PN 5391200390
2A fast rectifier usually survives most bad things that
happen with these supplies.

These supplies tend toward cascade burnup when they go South,
and can be tricky to fix. I scanned a bit of the schematic
for you. Good luck!

http://www.bright.net/~olduffer/vr9550ps.jpg

 

[[email protected]]

[email protected]>, [email protected]
says...


D1014 = MA2180 or RD18FB, Philips PN 5301921180
18V 1W Zener is there solely for protection - the circuit
would work fine without it under normal conditions.  The fact
that it is shorted suggests that supply regulation has gone
awry.  Common failures are C1015, 1000uF 16V output filter -
high ripple current is very hard on this capacitor - and C1007,
4.7uF 200V primary side snubber.

D1008 = ERB32-01 or RU2YX, Philips PN 5391200390
2A fast rectifier usually survives most bad things that
happen with these supplies.

These supplies tend toward cascade burnup when they go South,
and can be tricky to fix.  I scanned a bit of the schematic
for you.  Good luck!

http://www.bright.net/~olduffer/vr9550ps.jpg

Bill thanks so much for sending me that information. This unit belongs
to a friend who would really like to have me fix it if its possible.
Now at least I have a good shot at it. Best regards, Lenny Stein.