Jumperless JM20330 based SATA to IDE adapter hack

drugkito

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Aug 8, 2016
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I've bought a couple of these cheap random SATA to IDE adapters on the other bay last year or so but didn't even look at them till today.
To my surprise, there was no master/slave jumper present on the PCB. Adapter always presents the connected SATA device as a master.

So, here's a little hack how to get JM20330 based adapters without the master/slave jumper working as a slave on the IDE bus.
I'm not sure if this is a widely known thing or not, haven't really googled around much tbh.
Anyway, here's how to do, somebody might find it useful perhaps *shrug*.

Adapter in question:
_01.jpg _02.jpg

When two SATA hard drives are connected to the internal IDE connector on A4000D, both using this identical adapter at least, no hard drives are visible:
_03.jpg

Consulting the JM20330 datasheet reveals pin 33 could have been used for master/slave selection.
Unfortunately, on these boards this pin is tied to the ground (pulled low).

To modify the adapter to act as a slave we need to pull pin 33 high.
What you need to do is lift pin 33 from the pad (blue arrow in the 1st pic, red circle in the 2nd) so it is no longer connected to ground and solder a 1k resistor to a suitable 3.3V spot (in my case capacitor C101, red circle in the 1st pic):
_10.jpg _11.jpg

Next, connect the lifted pin with the resistor, effectively pulling the pin high:
_20.jpg

You might want to be extra careful not to break off the pin as it's a really tiny and fragile bit.
I broke it of course, so I had to file a bit of plastic off the chip :cool:.

Anyway, after the mod, lo and behold, both drives do get recognized and work properly:
_21.jpg _22.jpg

Maybe someone, someday, finds this info useful. Or not :p.
 
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