Brian, Is this something I can safely swap out and see if it works without putting the power supply in danger? Also, I've powered up my other power supply and it powers up with a 5A fuse but the +18 and -18 lights aren't lighting up, but the fuses are fine...any thoughts on that?
On Tue, Apr 19, 2011 at 11:07 PM, Brian Roth <[email protected]> wrote: > I knew Ike would have the definitive answer for the correct fuse value! > > Indeed, the rectifier diodes lead a rough life as they deal with large > power-on inrush surges due to charging of the large filter caps in the PSU. > > I'm sure Ike does this same thing: up-size the rectifier to the highest > amperage rating that will physically fit into the available space inside the > unit. It also doesn't hurt to up-size the PIV (voltage) rating as well. > > If the rectifier is a 4-terminal "bridge" that is bolted to the chassis, > like this: > > http://www.mouser.com/Search/Refine.aspx?Keyword=625-GBPC3506-E4 > > ....be sure to apply a thin film of silicon heat sink grease on the > underside of the bridge to help move heat from the bridge to the metal panel > when the bridge is bolted down. > > The example bridge I linked above is rated at 35 Amps. I believe I've seen > rectifiers in that same package rated at 40 Amps or more. > > Best, > > Bri > > > > > On 4/19/2011 21:03, Ike wrote: > >> Hi all, >> The correct mains fuse value for a stock PS-3 is 5 amp slow-blow, as >> Brian says. I THINK that the Sytek rebuilt units have up rated >> transformers which could account for the 7 amp fuse on your spare >> supply. If the fuse has vaporized, the most likely culprit is a failed >> bridge rectifier. Any competent tech should be able to replace it. >> Best >> Ike >> >> Ike Zimbel >> Zimbel Audio Ltd >> 416-720-0887 >> www.zimbelaudio.com <http://www.zimbelaudio.com> >> >> Sent from my iPhone >> >> On 2011-04-19, at 9:44 PM, Tommy Mokas <[email protected] >> <mailto:[email protected]>> wrote: >> >> Thanks for the response Brian. Well, the fuse is definitely blown, >>> which is disheartening at this hour...but alas, I'm going to go get >>> more fuses right now, and I'll report back soon. Hopefully its >>> something simple, although I'm doubting it is for some reason. Anybody >>> have a neotek tech in NYC, in case I need to make that call? >>> >>> On Tue, Apr 19, 2011 at 9:05 PM, Brian Roth >>> <<mailto:[email protected]>[email protected] >>> >>> <mailto:[email protected]>> wrote: >>> >>> If the inside of the glass tube of the fuse has black "crap" blown >>> all over, that sounds as if there is a short circuit somewhere >>> inside the power supply. But, if the wire link inside is merely >>> broken, it could be a case of "who knows?" >>> >>> I don't have schemos for that unit, so I can't say whether 5 or 7 >>> Amps is correct. It almost certainly needs to be a slow-blow type. >>> I think you will be OK trying a 5A slow-blow in there to see if it >>> blows again. If it blows again, STOP and have the PSU serviced. If >>> the fuse holds and the desk works, the next step would be to see >>> if 7A is actually the correct value, which could explain the blown 5A. >>> >>> Best, >>> >>> Bri >>> >>> >>> >>> >>> On 4/19/2011 19:09, Tommy Mokas wrote: >>> >>> Hello Neoteks, >>> >>> Quick question, if the fuse on the back of the power supply blows, >>> what should be my main concerns? There was no other reason for >>> me to >>> believe that the power supply wasn't functioning correctly >>> until my >>> biz partner went to turn it on and it didn't power up. I just >>> got back >>> into town to find a blown fuse in the back. >>> >>> The fuse that was in it was a 5A 250V 3/3. However I have a backup >>> power supply (which I've never needed) that has a sticker >>> indicating a >>> 7a fuse. I assume this referring to amps, but I want to be >>> sure. Is it >>> possible that the other power supply (which apparently serviced in >>> '96) has a changed value on this particular fuse? Is that a >>> mod done >>> to these? >>> >>> And for my final question, am I risking the power supply by >>> putting >>> the same fuse in only to have it blow again? I don't want to >>> do any >>> more damage but I do have work to do :). Any insight is really >>> appreciated, especially if you're a night owl such as myself. >>> Thanks >>> so much! >>> >>> Best, >>> Tommy Mokas >>> Casa Nova Studios >>> <http://www.twitter.com/tommymokas>www.twitter.com/tommymokas >>> >>> <http://www.twitter.com/tommymokas> >>> <<http://www.twitter.com/tommymokas> >>> http://www.twitter.com/tommymokas> >>> <http://www.twitter.com/casanovastudios> >>> www.twitter.com/casanovastudios >>> >>> <http://www.twitter.com/casanovastudios> >>> <<http://www.twitter.com/casanovastudios> >>> http://www.twitter.com/casanovastudios> >>> >>> >>> >>> >>> >>> No virus found in this incoming message. >>> Checked by AVG - <http://www.avg.com>www.avg.com >>> <http://www.avg.com> >>> >>> Version: 9.0.894 / Virus Database: 271.1.1/3582 - Release >>> Date: 04/18/11 09:22:00 >>> >>> ------ >>> >>> View the list online at: >>> <http://www.mail-archive.com/[email protected]> >>> http://www.mail-archive.com/[email protected] >>> >>> >>> You can unsubscribe at anytime by sending an email to >>> mailto:<mailto:[email protected]>[email protected] >>> >>> <mailto:[email protected]> with "unsubscribe neotek" in the >>> message body. If you have any difficulties, or questions --please >>> send an email to >>> mailto:<mailto:[email protected]>[email protected] >>> >>> <mailto:[email protected]>. >>> >>> The Neotek list is lovingly hosted by Catapult Web. Remember that >>> any message or reply sent to the list will be automatically >>> forwarded to all subscribers. >>> >>> Vive Le Neotek! >>> >>> Thanks. >>> >>> >>> >> >> >> No virus found in this incoming message. >> Checked by AVG - www.avg.com >> Version: 9.0.894 / Virus Database: 271.1.1/3582 - Release Date: 04/18/11 >> 09:22:00 >> >> ------ > > View the list online at: http://www.mail-archive.com/[email protected] > > You can unsubscribe at anytime by sending an email to mailto: > [email protected] with "unsubscribe neotek" in the message body. If > you have any difficulties, or questions --please send an email to mailto: > [email protected]. > > The Neotek list is lovingly hosted by Catapult Web. 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