if i run a 200 ohm test both resistors show 0.5
and for 2k test D4 actually shows 0.787 one way and “1.” other way
0.5 ohms sounds ok for a resistor but normally such a low value is used with power devices and the resistors are relatively large in physical size. With a very low resistance like that, any amount of voltage across the resistor will cause high currents, so the power rating of the resistor has to be high.
Also, you could be dealing with a fuse, or fusible resistor.
With digital voltmeters (DVMs) you can get away with a 200 ohm range but you should really get onto as low a range as possible if your resistors are that small.
If you have fried them due to over-voltage, there should be signs of burning. If you get your nose close to them you’ll smell it, or the PCB will have signs of burning on the traces. The traces may even melt. Get a high powered magnifying glass and have a close look. However, a high powere transient voltage will take out devices without showing damage. It depends how long you had the over-voltage applied.
With a diode measurements of 0.787 one way and 1 the other way, I am sure you have a device in parallel, like another diode. When you reverse bias a diode junction it should read almost infinite resistance.
Removing the PCB is not enough. You have to interrupt the diode circuit at one end.
I have spent hours and hours trying to repair hard drives and the returns are disappointing. I have opened them up, removed the heads and cleaned them but the tolerances are so incredibly small these days that getting them working again without the proper equipment is virtually impossible.
I have worked in electronics for decades and repairing a hard drive is far more complex than checking a few resistors and diodes. I would never try to discourage you from experimenting but I can tell you from experience that an over-voltage condition has likely taken out junctions inside chips and there’s no way to repair those, even if you can find them. Junctions in transistors are far more fragile than resistors and they’ll go just by sneezing on the chip.
The problem with chips is finding the right one, then there is the problem of changing a surface mount chip. The diodes and resistors you are testing are likely only an 1/8" long, if that.