Basic repair question for HFI2500d

[typo]

So, first off i want to thank diy audio, Perry Babin, and bcae for teaching me literally everything i know.

So, this amp that i got for FREE had all its output transistors ( i think, near the transformer, removed in the picture) showing 0 to 1 ohm over every combo of legs. There was black mars from three of them and two were cracked in half.

now, the other side of the board, one row of the mosfets they all show around 900 ohms. The other row all read EXACTLY 20 ohms. are they all bad? or is there something else wrong making them all show the same thing?

I searched diy for this amp and nothing came up, i have the HFI1000d and couldn't find that either.

i repaired 2 of my amps but those both required simply replacing 2 transistors so i'm in over my head right now.

thank you guys for the awesome forum!!

[timwebb]

does that amp use irfp064n as the power supply transistor? most likey the drive transistors have failed.they normally go when the main transistors fail. u will need to replace the gate resistors in the amp.

[Perry Babin]

The output transistors are the ones on the left in the photo. The FETs missing from the board are the power supply transistors.

You need to remove all of the power supply transistors on the side where the cracked ones were and then re-check what's in the board.

You'll need to replace all of the ones in the group with the ones that cracked.

[typo]

So, the resistors going to the shorted components, (which were IRFP064N, 6 per side)(shown in blue on the picture) all showed what they were labeled: (47ohm) does this mean i still need to replace? will they not perform under current?

The resistors for the green and red components seem good (compared to each other and their markings)

the transistors labeled in green and red:
There are 5 of each kind in a single row, to total ten per side, 20 overall. the 5 near the blue lines: have sort of a script/logo/bold "F" followed by 10344. the other 5 towards the purple dots have the same "F" followed by M0351. i had some trouble finding the parts online, any substitutes?

pic 2: i re-checked the row labeled with green and found i only had resistance with one leg. 900ohms with the red lines 0 with the light blue. i assume i need to replace all 20. (the row in red all near 0 ohm)

are the "drive transistors" the ones i labeled green and red?

Perry, "then re-check what's in the board. " I'm sorry, i'm not really sure what you mean by this. the rest of the transistors? or where the transistors i removed were?

Finally, the purple dots are IC's i belive, TL075CN should i troubleshoot these at all?

THANK YOU

[Perry Babin]

If the resistors are within the tolerance indicated by their markings, they don't need to be replaced.

TL072s are op-amps.

The green and red transistors are the output transistors.

Do you read exactly 0 ohms for all of the output transistors from pin 1-2?

What is the value of the gate resistors for the output transistors?