Resistors assistance

[Sunday2471]

Can you tell me if the IRF across the board are all the same to replace? Some have 29k on them while the others have 30k.

 

[Sunday2471]

are these resistors the same when purchasing from Amazon? Can’t find 29k or 30k in the product specs

 

[rayma]

These are mosfets, not resistors. Note the ferrite beads on the gate leads.
The tabs are electrically hot and require isolation from the heat sink.
https://www.infineon.com/cms/en/product/power/mosfet/n-channel/irf3205/
Always use a reliable vendor, such as DIgikey, Mouser, etc.

 

[newvirus2008]

Note the ferrite beads on the gate leads.

The middle one is the drain, isn't it ?

 

[rayma]

Maybe so. But definitely not resistors.

 

[profiguy]

The pinout on those IR fets is "GDS" looking at it from the front.

 

[Mooly]

Threads merged. Please do not start multiple threads on the same topic.

 

[Perry Babin]

He doesn't need my second opinion but never buy semiconductors from Amazon or eBay. There may be a small number of legitimate vendors there but there are far more selling counterfeit or second-rate parts. Digi-key and mouser are the most user friendly sites.

All below the IRF3205 on the face of the FET are production codes and can be ignored when looking for replacements but I prefer for the numbers to match for groups of parallel parts.

https://www.infineon.com/dgdl/irf3205pbf.pdf?fileId=5546d462533600a4015355def244190a

The gate resistors and driver transistors for the 3205s may have failed as well as the output transistors (causing the 3205s to fail).

Read through page 20 of the following site:
https://www.bcae1.com

 

[Sunday2471]

 

[Sunday2471]

View attachment 1295755

First time I have ever opened an amp up. This is what I found. I know the mosfets need to be replaced. What else was probably damaged? Just need a starting point with my meter.

 

[PapaZBill]

What is the amp model?

All IRF3205's will need to be replaced. Preferably, matched as Perry mentioned. If you purchase from DigiKey, Mouser or another reputable vendor be sure that they have the same date code.

You will most likely replace a number of gate resistors and the gate drivers.

Once you have sent the model and post a picture of the entire board and preamp I can help guide you through the necessary repairs.

 

[Sunday2471]

Kicker zx750.1

 

[Sunday2471]

 

[Sunday2471]

I actually have two of these amps. Two different gens. They both go into protect mode. One clicks over and over going into protect mode. The other goes straight into protect mode.

 

[Sunday2471]

Maybe I can just take both amps and make a working one. Circuit board looks the same.

 

[PapaZBill]

Can you post pics of the other Rev?

 

[phase]

Going to have to read a bunch in order to get through this one, amp repairs aren’t like changing fuses.

Search to find other threads like this one, might be helpful possibly.

https://www.diyaudio.com/community/threads/need-schematic-for-kicker-zx750-1.143940/