# Help ID blown transistor on Phoenix PB9 board



## Daveyj199 (Mar 25, 2020)

HI ALL,
My first post of 2022. Happy b-l8'ed new year! I have a client with a screeching sound board - a phoenix PB-9 diesel. Can anyone help me identify transistor Q2 in the following photos of the board ? Its too damaged to make out the code...
Thanks,
Dave


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## Daveyj199 (Mar 25, 2020)

With the help of a stereo microscope and some online sleuthing into what this device might be I've now determined the part number.... for anyone else suffering this failure... its a high current PNP transistor part number FZT951. Its function on the board appears to be charge current regulation for the 3.7 volt battery.

And FYI, I contacted Phoenix by email at the time of my first post and have yet to get a reply. I don't know what is going on with that company...


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## Greg Elmassian (Jan 3, 2008)

So, are you going to replace it right off, or are you going to try to find why it failed? (something to do with excessive charging current being drawn?)

Yes, Phoenix is way behind and they are terrible at responding. It really does not take a lot of time to respond to emails, they could just cut and paste a standard response.

They DO have a disclaimer on the site:










And there are 32,000 of them in stock at Digikey, so no "global shortage" about a buck each.

I get that parts to make NEW stuff can be hard to get or upped in price, but REPAIR stuff? 

Too many people using a blanket excuse I think.

Greg


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## Daveyj199 (Mar 25, 2020)

Thanks, Greg ,
Yes I spotted many FZT951 in stock here and there. But , Today I found the LEDs and lamps on the rear light board are all fried so There was obviously a power surge that took out these and the sound board. I tried substitution of a close spec PNP transistor on the sound board but it’s still squealing like a pig so it’s shot. Yes I did test everything else I could practically test on this board. Tons of microscopic diodes and what not can’t find anything else. Luckily Winona up here in Canada has an NOS one as these are NLA after 12 - 15 years. ...oh well !
Dave


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## Greg Elmassian (Jan 3, 2008)

Sorry to hear was not an easy fix.... but you found a replacement, that's a positive!

Greg


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