Pioneer 1280 Power supply issue

[Leokarma]

I assume you mean 0.001 ohms, so in that case it means the diode is shorted out and needs replacement.

sorry ohms.

Is UF4005 the only replacement for S1B-01-02 ?

I have 1N-4002, 1N-4007, 1N-4148 and 1N-5257B. Is any of these equivalent ?

 

[markthefixer]

use the 1n4007 (1000v 1 amp) , the UF diodes in a power rectification position will have more "commutation" hum due to the crisp Ultra Fast response.
uf4005 is 600v 1 amp ultra fast switching diode

and a reading response of 0.001v in a DIODE test is a valid reading, albeit a shorted diode. The diode test response is expressed as volts. Forward volts.

the 1n4002 is too low of a voltage (200v 1 amp) even though a 10e2 is supposedly 200v at 1 amp.
1n4148 is also too low of a voltage AND ALSO too low of a current (Small Signal 100V Io/200mA)
1n5257b is a 33 V, 0.5W zener diode. - totally inappropriate.

 

[Leokarma]

use the 1n4007 (1000v 1 amp) , the UF diodes in a power rectification position will have more "commutation" hum due to the crisp Ultra Fast response.
uf4005 is 600v 1 amp ultra fast switching diode

and a reading response of 0.001v in a DIODE test is a valid reading, albeit a shorted diode. The diode test response is expressed as volts. Forward volts.

the 1n4002 is too low of a voltage (200v 1 amp) even though a 10e2 is supposedly 200v at 1 amp.
1n4148 is also too low of a voltage AND ALSO too low of a current (Small Signal 100V Io/200mA)
1n5257b is a 33 V, 0.5W zener diode. - totally inappropriate.

OK thanks. I'll replace with 1N4007 later today and report.......

 

[glen65]

I pulled one leg of D13 and checked. D13 seems to be OK. It's showing 0.675 V in one direction and "OL" in the other.

I also pulled one leg of D11 and checked. It's showing 0.001 V in both the direction.

Thats odd, you said it was showing "OL" in both directions which would indicate its open.
Anyway, good to see you're making progress.

 

[Leokarma]

You guys rock......replaced D11 and everything working fine

I'm getting 13.4 VDC on 16, 17, 18. Both channels tested and are working fine including FM.....
Thanks to all of you.....

 

[petehall347]

well done in getting it working ..
just being academic here ..i still don't understand the positive voltage you were getting at pin 15 ..

 

[Leokarma]

well done in getting it working ..
just being academic here ..i still don't understand the positive voltage you were getting at pin 15 ..

Thanks.

Actually if you refer to post #14 you said "......power on of course ..then for fun pull fuse 2 & measure voltage at pin 15."
When I measure the voltage on pin 15 (black to ground) I was getting +0.5 VDC. Now I'm getting +11.4 VDC.

 

[petehall347]

i cant figure that one out just yet .. if its working fine that's ok ..maybe i am just missing something that someone might be able to explain to me . i am always learning .