DeLonghi AC Remote only accepts 3V

[cstout]

Hello all, I've been looking into this portable air conditioner's remote control and can't find what could be causing the problem - or possibly this remote is just terribly designed.

The remote only works at exactly 3V - if I drop it any lower, using my bench power supply, to say, 2.9V then the remote will not flash the display and turn off. I don't have any AAA batteries that are exactly 1.5V each so I'm not sure if this remote is designed this way - to only use the freshest possible batteries, or if there's a failed component in the mix.

I can't find any schematics for it, but the board reads:

Goldcorolla
COR472R V1.1
2014-11-25

SMD chip: HB8514F F1HP11.1 (photo attached, I can't find anything on this either)

I've done the following so far:

• replaced the E1 capacitor as it did not read the proper value (16V, 42uF)
• verified the Y1 crystal is reading properly - it is
• removed and tested all SMD resistors and capacitors
• replaced all 0 ohm resistors with jumper wire

There were two 0805 white smds, with no resistance, no capacitance, and no continuity - so my best guess is that these are blown smd fuses. Really not sure though, but there are no markings on any side of it that I can see under the microscope. They were located at C2 and C3.

J2 was empty from the start.

The remote works when 3V is applied but does not at any lower voltage. I'm not sure what to check next.

[cstout]

If C2 and C3 were in fact fuses, would it be worthwhile to use magnet wire on these pads and test? I'm hesitant simply because the remote works normally at 3V and I'd assume a blown fuse should stop normal function. It's all very odd to me.