To make a long story short, I've got this Dragon Miner A1. One of the modules says it hashes at 750gh, but in reality it just isn't working. So, I did some research and found out that one of the VRM chips is probably bad (If my theory is wrong please correct me) and needs replacing. So the module apart today and discovered 2 VRM chips, one is a 1.8V and the other is a 3.3V. They have writing on them and I searched it up and found some, but the last string of numbers is different on all of them. Does the last string of numbers matter? I am also not currently sure of the amperage on the original chips. So if anyone knows that info please share that with me.
The 1.8V one is as follows: AMS1117 1.8V H418KE
The 3.3V one is as follows: AMS1117 3.3V H421PE
If the last set of numbers matters could someone tell me what they mean?
Thanks,
dako44
here is the datasheet of the LDO chips:
http://www.advanced-monolithic.com/pdf/ds1117.pdfI didn't check the pinout, but it's very likely that they are compatible with ncp1117, ncv1117, and many other "1117" LDOs, all outputting 1A.
But first, you'll need to check if the Vout is out of specs.
Center pin is the vout.
Most of the time, you can use almost any screw from the heatsink as a ground reference (or simply use pin 1 of the LDO).
I'm not too familiar with the dragon units, but I'm not sure the LDOs are at fault, maybe just the asics that went bad.
from what I remember (but I may be wrong), the I/O are all chained together. I don't know what will happen if one chip in the chain fails.