C734T Touch Working/Audio is Not

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1

I recently installed a new touchscreen for an Acer C734T and the touch function wouldn’t work. To get touch working, I ran the line ectool cbi set 8 0 4. Touch function works now but I’m not getting any audio output. I’ve tried restoring factory setting and recovery of ChromeOS, nothings working. Any help would be appreciated.

2

why? what made you think that was the correct thing to do?

well, because you broke the audio config in CBI, running a command you didn’t understand

3

My understanding was this was used to set the SSFC value for the touchscreen, not the audio config.

4

I was also going off previous advice you had given to run:

ssfc_val=$((ssfc-val | 0x40))

ssfc_val=$((ssfc-val | 0x80))

ssfc_val=$((ssfc-val | 0xc0))

This had the same effect but both touch and audio stopped working.

Touch only began working when I set the value to 0.

5

SMH.

did you bother reading/saving the previous value before you nuked it?

6

yeah I have cbi_info from chrome://system before and after running the code.

7

Before

IMG_0991.HEIC
IMG_0991.HEIC3024×4032 5.27 MB

8

After

IMG_0993
IMG_09931920×2560 993 KB

9

what would be the right way to get touch working on this device?

I followed others and your advice on previous posts to get the touch working. Nothing about audio config was ever mentioned.

10

I don’t even know what device we are dealing with. what’s the board name? make/model are useless.

11

Dedede is the board name. maglith is the model.

12 
	field CAMERA_WFC 38 40
		option CAMERA_UNPROVISIONED 0
		option CAMERA_OVTI5675 1
		option CAMERA_OVTI8856 2
	end
	field CAMERA_UFC 41 42
		option CAMERA_UFC_UNPROVISIONED 0
	end
	field CAMERA_VCM 43 44
		option CAMERA_VCM_UNPROVISIONED 0
		option CAMERA_VCM0 1
	end
	field TS_SOURCE 45 48
		option TS_UNPROVISIONED 0
		option TS_ELAN_6915 1
		option TS_ELAN_6918 2
		option TS_ELAN_0001 3
		option TS_RAYD_0001 4
		option TS_WDHT0002 5
		option TS_GTCH7503 6
		option TS_ELAN_9004 7
	end
	field AUDIO_CODEC_SOURCE 49 51
		option AUDIO_CODEC_UNPROVISIONED 0
		option AUDIO_CODEC_DA7219 1
		option AUDIO_CODEC_RT5682 2
		option AUDIO_CODEC_ALC5682I_VS 3
	end
end

from your pic above, SSFC was not set at all, so everything defaults to unprovisioned

was audio working before you messed with it?

13

Yes it was working.

The driver for the screen I installed is ELAN0001. I can see that in dmesg tab.