Power supply diode help

[MGS]

I'm hoping someone can help me with the SMPS in my Sony BDP-S1E Blu-ray player.
It appears two of the four GPP20J rectifier diodes have shorted out which has taken the ceramic fuse out also. I can replace the diodes and fuse but I cannot source the same diodes as in the circuit. I spoke to an electronics shop who say I should be able to use BYM26E avalanche diodes but I am unsure if this is the case. I do not have an equivalents book so can anyone suggest a suitable part to use instead of the GPP20J. It was quite an expensive Blu ray player and I would like to get it working again. I intend to replace All of the diodes. The caps all look good but I cant test as I do not have an ESR meter.

Thanks in advance.
Martin

[SamRodgers]

It's a 600 volt, 2 Amp glass passivated junction diode.
I'd try a 1N5062. http://www.vishay.com/docs/86000/1n5059.pdf
I'd also check the capacitor ESRs. You can get a cheap ESR meter from Hong Kong via eBay. Or support England and buy one from Peak:
http://www.peakelec.co.uk/acatalog/jz_esr70.html

[MGS]

Thanks for your replay, in that case wouldn't I just need the 1N5061?
For test purposes I tried some 1N5406 from maplin's in place of the 2 blown GPP20J's and replaced the blown fuse and she powered up and functioned OK.
I'm not really sure why Glass passivated diodes are specified or do I know the difference.
I think I may have found the reason they popped though! the fan in the back of the unit is not working, but I 'm not sure if it is temp controlled or if it should be on all the time. I measured zero voltage from the header pins that run to the fan during the first 10 mins of operation.
The problem is getting hold of parts as I don't really do repairs much these days, do you think I should just leave those 1N5406 in there long term or change them? I can get some SF38G from ebay which are Glass passivated ones of a higher ampage rating. http://www.ebay.co.uk/itm/5-X-DIODE-FAS ... 5ae9476345

[Simon (Webmaster)]

My Sony blu-ray player (cheaper model) has a temperature controlled fan, and it hardly ever switches on. Yours may well be the same. It might be worth checking the temperature inside the case after running it for 30 mins or so of playing a disc.

[MGS]

Thank you, it appears you are correct Simon, after the unit was on for 45mins the fan kicked in (It's so quiet I've never heard it running before)
An ESR meter like the one at Peek would be very handy but as I rarely do repairs for people now (This was my own Blu-Ray Player) I cant really justify the cost. The caps in this player are of high quality and as I said look perfect so I will have to see if the repair lasts with the correct diodes in place.
I Would still like opinions on keeping or changing the diodes listed above though.

[carsi]

A glass passivated diode basically does the same function but reduces the leakage current because of its preparation stage, the whole open P-N junction of the diode is coated with a passivation glass layer. The passivation glass layer is applied to the whole cutting area of each diode chip and fired separately during the preparation procedure. The open P-N junction of the glass passivated silicon semiconductor diode chip has a positive beveled cut, thereby the reverse voltage resistance may be enhanced and the possibility of leakage may be reduced...

smt pcb assembly