🚀 go-pugleaf

IRFZ34 available from Digi-key http://www.digikey.com , East Coast
Transistor www.kenwoodparts.com . Can be replaced with IRFZ44 for an
upgrade. Usual causes for failure like this in a car audio amp DC-DC
converter is shorted finals, too low impedance load, low voltage, or some
dummy hooked it up backwards. Make sure to check the gate bias resistors,
and if this one uses a TL494C PWM controller, check the transistors that
drive the FET's. A quick-n-dirty way to check most of these car amp power
supplies is to remove the bad FET's and power up the amp, and use a
oscilloscope to check for a clean square wave with little or no DC at the
connection the FET gate goes to. This eliminates putting in new FET's only
to cook them in the event the PWM/drivers were damaged. Also check the
reverse-bias diode connected across the battery terminals. If the unit was
connected backwards, it may be shorted.


-- 
Jammy Harbin
J & J Electronics, Inc.
227 S. 4th St.
Selmer, TN 38375
731-645-3311
"Matt Flax the original flatmax" <flatmax@noSPASMS.ieee.org> wrote in
message news:WHUtc.15880$L.361@news-server.bigpond.net.au...
> HI I am in the process of fixing a car amp.
> These transistors are clean blown off ! I don't know how it happened
> 'cause it arrive to me in this shape.
>
> Anyways I have these transistor packages to replace :
> http://www.pgb.unsw.edu.au/~flatmax/burntTransistors.jpg
>
> The packages say (on the casing) :
> SEC
> 629
> IRFZ34
>
> Could anyone tell me how to find an equivalent (or the same) package ?
>
> thanks
> Matt
>