Re: Went Dead

Clark Martin
 

With the symptoms described there is a microscopic chance it’s something other than a shorted MOSFET. You might want to consider replacing both final transistors. Whatever killed the one that is shorted may have damaged the other. Make sure to buy several spares, this may not be the first time you need to replace them.

I’d strongly suggest putting a fuse inline, this may protect the final transistors from future damage and also protect your power source from overload if it does happen again.

Make sure you replace the thermal grease between the transistors and heatsink. Don’t forget to set the bias adjustment for the new transistor (you should probably verify the bias adjustment for the other.

Below are some reputable sources for replacement IRF510s:

https://www.mouser.com/ProductDetail/Vishay-Siliconix/IRF510PBF?qs=sGAEpiMZZMshyDBzk1%2fWi1F3z9PgzPBnjAas2zQPJco%3d


https://www.jameco.com/z/IRF510-Major-Brands-Transistor-IRF510-MOSFET-N-Channel-100-Volt_209234.html?CID=GOOG&gclid=EAIaIQobChMI7cCJuLTW2wIVEsNkCh3wXQNhEAkYASABEgLGAfD_BwE

https://www.arrow.com/en/products/irf510pbf/vishay?utm_source=google&utm_campaign=g-shp-us-fet_transistors&utm_medium=cpc&utm_term=PRODUCT+GROUP&gclid=EAIaIQobChMItr2Vt7TW2wIVQ41-Ch1L7gdWEAkYASABEgLXDfD_BwE&gclsrc=aw.ds&dclid=CIaN0ti01tsCFUzLZAodA5cAUg

https://www.alliedelec.com/vishay-pcs-irf510pbf/70078850/?mkwid=s6sX9YbUa&pcrid=30980760979&gclid=EAIaIQobChMItr2Vt7TW2wIVQ41-Ch1L7gdWEAkYBCABEgKC6PD_BwE

http://www.newark.com/vishay/irf510pbf/n-channel-mosfet-100v-5-6a-to/dp/63J7301?mckv=sNl2veeHe_dc%7Cpcrid%7C81515566701%7Cplid%7C%7Ckword%7C%7Cmatch%7C%7Cslid%7C%7Cproduct%7C63J7301%7C&gross_price=true&CATCI=pla-148794670821&CAAGID=20376568701&CMP=KNC-GUSA-GEN-SHOPPING-63J7301&CAGPSPN=pla&gclid=EAIaIQobChMItr2Vt7TW2wIVQ41-Ch1L7gdWEAkYBiABEgK82_D_BwE&CAWELAID=120185550001121418

Clark Martin
KK6ISP

On Jun 15, 2018, at 12:24 PM, Bill Watkins <kf7yxs@...> wrote:

Thanks,

So, one mosfet is shorted. I'm no electronics wiz so I have to ask basic questions. It's an irf510, right? Fry's electronics shows no item of that name. Is there another company that makes something generically the same, or is there a similar item available at Fry's that I can replace it with?

Is that the real issue? With the zero ohms from source to drain on one transistor and with the unit powering up when brown wire disconnected is shorted mosfet the answer to this problem (at least short-term, anyway)?

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