Blown IRFZ44N

[N-Channel]

F10U20DN

These are the output rectifiers for the DC-DC converter. Two positive diodes (common anode) for the (+) rail, and two negative diodes (common) for the (-) rail. This arrangement is very common in car amplifiers. you can replace them with the two following parts from OnSemi (formerly Motorola):

MUR1620CT - Common-anode diode pair for the positive bus
MUR1620CTR - Common-cathode diode pair for the negative bus.

Here are their datasheets:

http://www.onsemi.com/pub/Collateral/MUR1620CT-D.PDF
http://www.onsemi.com/pub/Collateral/MUR1620CTR-D.PDF

These parts are very easy to get, and should serve your purposes fine.

Regards,

Steve

 

[cruck00]

How do you normally test a diode?

 

[cruck00]

I compared the values for the on semiconductor MUR1620CTR and the fairchild FFPF10U20DN and the values did not match up in some of the categories (I fm, V fm, i R) is this going to make a difference or are they interchangeable?

 

[Perry Babin]

If yours are not physically broken or otherwise defective, there's no reason to replace them.

The 1620ct would be a good replacement. The ctR is reverse polarity (diodes on body of component face outward).

 

[cruck00]

I am going to test these two diode rectifiers to decide if I need to replace them or not could you please give me an idea of what kind of readings I should get.

 

[Perry Babin]

The test procedures for the most common components are on the following page.

http://www.bcae1.com/ampfail.htm

 

[N-Channel]

Interchangeability and Test Procedures

Perry,

That is an excellent tutorial webpage for car audio, and testing audio components in general. Concise & to the point.

Cruck-

I was not able to access the Fairchild website today (our work CPUs have many firewalls and filters), but the MURs should do just fine. 1620 yields 16A @200PIV. That's 8A per leg of each dual diode.

Steve