GI 636 Rectifier Diode equivalent

[intelogic]

Hi all,

I have a faulty rectifier diode marked GI 636 (General Instrument?) that I'm looking for specs and/or an equivalent for.  It's part of the PS rectifier in a Rotel amp.

None of my data books has this one, nor a search on the web.  Would it be safe to assume a 1N5403 or 1N5404 would be suitable?

Thanks and regards

[floobydust]

Uh what package is it, how about a pic, what model Rotel... the more info you give us the easier it is to help.
1N540x has fat leads that may not fit the PC board and they are slow recovery.

[fzabkar]

Is this of any use?

https://mirrorservice.org/sites/www.bitsavers.org/components/gi/_dataBooks/

[intelogic]

Thanks guys,

Some pics added.  It's a Rotel RA-412.  Marked on the attached as D901 to D904, specified as "HIFI SPECIAL X4".

Thanks also for the link to the data books - checking through now!  The existing diode legs are ~1.3mm dia.

Cheers

[floobydust]

It's a Japanese build so I'd expect it would not use any American semiconductors. A JEITA package and possibly Sanken, Toshiba, Hitachi etc. The "hi-fi special" is likely soft-recovery for less rectifier switching hash and RFI ala 1976.
In a perfect world I would replace all four, check width might be too wide body. Use fast recovery and this is only 2x25W so even 2A parts enough. By today's standards the power transformer is good for 500W lol.
UF5404 or SBYV29-200
BYV28 sinterglass SOD-64 is fat leads 1.35mm and expensive but best recovery
1N5404 if it's on the cheap.
There should be an RC snubber across the transformer secondary but a scope check can show if there is too much ringing.
Down the rabbit hole https://www.desmith.net/NMdS/Data/Linear%20Audio%20-%20Soft%20Recovery%20Diodes%20Lower%20Transformer%20Ringing%20by%2010-20X.pdf

[intelogic]

That's great! Thanks mate for your reply and the info.

All understood and agreed on the replacement of all 4, UF5404 it is.  I'll also do a full check afterwards, but yes on the transformer rating

oh and thanks also for the rabbit hole reading - you learn something new every day!

Cheers