Blue circles are the IRFP064N
Red circles are the IRFP054N
Yellow circles are FMU32U
Pink circle was the C4468 that looked out of place
also in my last post i meant IRFP064N ( i said IRFP64N)
Red circles are the IRFP054N
Yellow circles are FMU32U
Pink circle was the C4468 that looked out of place
An externally hosted image should be here but it was not working when we last tested it.
also in my last post i meant IRFP064N ( i said IRFP64N)
It's likely that the power supply failed and someone replaced only 2 of the FETs. It's likely that the others had failed also but the previous tech failed to notice.
You'll need to replace all of the FETs in that power supply (6 FETs) and the gate resistors that are out of tolerance.
After you remove the FETs, you need to measure the DC voltage on the gate resistors. All should have the same voltage and should be approximately 5v.
Do you have an oscilloscope?
You'll need to replace all of the FETs in that power supply (6 FETs) and the gate resistors that are out of tolerance.
After you remove the FETs, you need to measure the DC voltage on the gate resistors. All should have the same voltage and should be approximately 5v.
Do you have an oscilloscope?
Do you happen to know what gate resistors this board use's? Also will i be replacing all the IRFP054N's with IRFP064N's?
And does the C4468 belong in that spot or did the other owner add that wrongly as well?
Unfortunately i dont have an oscilloscope yet.
And thanks a ton for your help so far Perry, i just hope one day i know amps half as much as you do!
And does the C4468 belong in that spot or did the other owner add that wrongly as well?
Unfortunately i dont have an oscilloscope yet.
And thanks a ton for your help so far Perry, i just hope one day i know amps half as much as you do!
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There should be six IRFP064Ns in each power supply. I've never seen the IRFP054Ns used in any amp so I suspect that they're not the original FETS in this amp.
The C4469 was definitely not supposed to be in this amp.
The C4469 was definitely not supposed to be in this amp.
I removed all the fets and the amp will now idle correctly with no protection lights, The led comes on as it should to signal the amp is functioning.
All gate resistors test within tolerance as well.
I will be ordering some new P064N's to throw in it as well.
current draw is no longer excessive.
All gate resistors test within tolerance as well.
I will be ordering some new P064N's to throw in it as well.
current draw is no longer excessive.
is there a nominal resistance / voltage i should look for on the outputs?
they are all IRF9640 , IRF640N and the former owner put two IRF640's in there
im assuming the two IRF640 should be IRF640N
they are all IRF9640 , IRF640N and the former owner put two IRF640's in there
im assuming the two IRF640 should be IRF640N
You should not read anything near 0 ohms when you place the probes on the legs of any individual transistor in any configuration.
If the 640Ns appear to be the originals, that's what you should use. If I'm not mistaken, these are in groups of 3. If so, you'd need to replace the two that are different and the one that was working in parallel with those transistors.
If the 640Ns appear to be the originals, that's what you should use. If I'm not mistaken, these are in groups of 3. If so, you'd need to replace the two that are different and the one that was working in parallel with those transistors.
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