I dont recall if I have explained it in other threads, but here is what happens with the Hybrid IC:
The resistors are printed directly onto the ceramic substrate, Just like standard SMD resistors. Also, they have a laser etch cut to trim the carbon into the correct value of resistance. So, This is all well and good until you introduce capacitor electrolyte from the tank farm that sits just below. it gets infused into the carbon composition and alters the values of the resistors, or causes the resistors to either open, or start varying widely in resistance under load, introducing noise or instability.
Reflowing and heating up the hybrid can sometimes drive that out, but not always, sometimes its beyond repair and the Hybrid has to be replaced.
This is usually what happens and is almost always fatal.
So what worries me is the guy doing the schematic for the Hybrid, While nice, it wont be a good reference to manufacture one-off replacements because of this problem. The resistance values I am seeing in the schematic does pose problems. So the only way to precisely reverse engineer a Hybrid, is to use a known good working one with Zero issues. All mine have issues so I havent been able to do so. Getting accurate resistance readings for a reverse engineering process will be difficult, if not impossible due to the above scenario.
I am seeing 7.6Meg and 7.5Meg and 9.7Meg resistor values in here. which I know a couple of these arnt correct, and several other resistor values are all over the place. So its not a good scenario.
The resistors are printed directly onto the ceramic substrate, Just like standard SMD resistors. Also, they have a laser etch cut to trim the carbon into the correct value of resistance. So, This is all well and good until you introduce capacitor electrolyte from the tank farm that sits just below. it gets infused into the carbon composition and alters the values of the resistors, or causes the resistors to either open, or start varying widely in resistance under load, introducing noise or instability.
Reflowing and heating up the hybrid can sometimes drive that out, but not always, sometimes its beyond repair and the Hybrid has to be replaced.
This is usually what happens and is almost always fatal.
So what worries me is the guy doing the schematic for the Hybrid, While nice, it wont be a good reference to manufacture one-off replacements because of this problem. The resistance values I am seeing in the schematic does pose problems. So the only way to precisely reverse engineer a Hybrid, is to use a known good working one with Zero issues. All mine have issues so I havent been able to do so. Getting accurate resistance readings for a reverse engineering process will be difficult, if not impossible due to the above scenario.
I am seeing 7.6Meg and 7.5Meg and 9.7Meg resistor values in here. which I know a couple of these arnt correct, and several other resistor values are all over the place. So its not a good scenario.
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