Type 4 Class D Automotive Car Amplifier 1500w 1800w Repair Process

Hello viewers!
First I would like to announce that Keysight has approved my workbench challenge submission! Please check it out and give me a vote at www.keysightbe...
What I have is another type 4 class D amplifier repair where I guide you through my process and what you should expect at each point of the Class D circuit. This one had a secret damaged VIA that one would easily oversee.
These boards are very common so a good understanding of the inner workings is a must if you plan on repairing these.
Here is a list of common parts that you will need for this job.
IRF640N transistors
2X and 2T transistors
Signal diodes (1n4148)
5v regulators
10-ohm gate resistors
10k pull-down resistors
The drive cards typically don't fail but here is a list of components for the cards:
74HC02
TL072
LM319
Signal diodes (1n4148)
Again thank you all for watching!
Ellensburgamplifier.com

[@roberthemphill6242]

Grest Todd!! As always. Those 2x transistors are what my problem has been all along. They have drove me nuts for months or a year since I've had them. Tossed them and ordered a new batch from mouser.

[@ellensburgamplifier]

Good to hear Rob. A person never knows about the quality of parts until thoroughly tested. Even my LCSC orders go through testing as I don't have much trust in today's discrete components.

[@user-vq4ed6lh5t]

Thank you sir

[@MrWaalkman]

Excellent as always. :) I'm working on a ShopLink Flash 2.0 that has a faulty USB connector. I found a cold solder joint on the negative pin, and tried to fix it, but it looks like I need a new connector.

[@PowerToneAudio]

I suggest you remove the header bro, i had an amp with header in and the board fell down after some time due to vibration secondly after sometime contact will get loose and amp will unstable functioning.

[@ellensburgamplifier]

Thank you Andres, these are just test boards and nut boards that are in use. The headers are for quick testing of cards that I rebuild.

[@Ali-nb1tx]

Hi, I have 2000w Kac-ps917D Kenwood amp as soon as I increase the volume it goes into protection mode, after troubleshooting found out that there is continuity between +ve and -ve power terminal checked the caps and fets everything is fine, any idea what should I look for?

[@ellensburgamplifier]

This is something I would have to see on a scope to be able to give any insight too. Sounds like an over-current circuit is being tripped.

[@Ali-nb1tx]

Thanks, I wish I could ship it to you.