TECHNICS SB-AS500 Repair

[KeepItSimpleStupid]

Photo - dud!

 

[Sid Snake]

Not to good on the forum etiquette as my first time using one!
But I am sure that I will get it

 

[Sid Snake]

Is this ok

 

[KeepItSimpleStupid]

The top227Y is probably this part: **broken link removed**
==
I did download the SM from electrotanya.

 

[Sid Snake]

yes I am happy with the TOP227Y I am able to acquir it without any problems.
It is the other one that I have a issue with, just need to now if the BC2726-ND is your choice now you have the schematics or if you would fit something different?
Sid

 

[KeepItSimpleStupid]

I'm still a bit confused if it's supposed to be inrush current limiting or protection. Maybe it really is inrush current limiting. The data sheet for the OEM part seems wrong. Here https://www.soselectronic.com/a_info/resource/a/pdf/ntc.pdf is an article on NTC selection for inrush current limiting.

The voltage on the NTC/PTC will be about 170 V and not 400 VDC.

I think, I'll change my recommendation to this https://www.digikey.com/product-search/en?mpart=B57235S100M&vendor=495 one and assume it's for inrush current limiting.

 

[Nigel Goodwin]

I'm still a bit confused if it's supposed to be inrush current limiting or protection. Maybe it really is inrush current limiting.

Nothing confusing about it at all, it's an inrush surge limiter - the circuit makes that perfectly clear.

 

[KeepItSimpleStupid]

Nigel:

This https://www.allproducts.com/ee/taos/03scl_print.html datasheet for the OEM part (SCL 083) doesn't make any sense to me. the zero power resistance is lower than the max current resistance which to me suggests a PTC. The schematic labels it as an NTC and so does the datasheet.

This https://www.soselectronic.com/a_info/resource/a/pdf/ntc.pdf datasheet has it right for an NTC.

 

[Nigel Goodwin]

OEM numbers are pretty well meaningless, just because you managed to find something with asimilar number doesn't mean it's the same part.

Like I said, it's an NTC for inrush current limiting, as it's absolutely clear from the circuit.

You could easily replace it with a 4.7 or 10 ohm 5W wirewound resistor, certainly for testing purposes.

As far as replacing it with the correct part goes, get the exact spare part from Panasonic, and certainly not something with a similar number but a completely different function.

 

[Sid Snake]

Hi Nigel
Thank You for the input and help.