Left output from headphone jack inop

Did a dumb thing.....running audio-video for our church I used a mono jack to feed sound into the building sound system, now left output is kaput. Speakers work normally, just the headphone jack is messed up.

Looking at the manual PDF I don't see any schematic, is there a board I blew up? I've had the bottom off so I could look next week sometime, any advice would be fantastic.

 

What model??????:hi2:

 

Hi Shawn you know that might be important!

CF-74CGDCDBM

 

What are you using to test the jack? Try another set of speakers to verify it's the laptop.
Headphone jack is mounted directly to the motherboard.

 

My speakers work fine, my Bluetooth stereo headset works ok. I can go into sounds in control panel and adjust the balance on the headset (Bluetooth) and test the left and right speakers on the laptop. I have used two headphones and an external speaker set and the left side from headphone jack is inoperative. Being on the MB is not good. I'm bummed I did a really bad one.

 

Try reloading the sound drivers; if yours uses the RealTek audio chipset, the driver may have misinterpreted your connection as a mic in or subwoofer out. (RealTek tries to auto-identify any connection)

Go to Control Panel
Disable, then Uninstall RealTek Audio device
Reboot & allow it to reinstall drivers

If that doesn't fix it, odds are you need someone with soldering-fu to replace your headphone jack; I'm not certain what the part # might be. You can try resoldering the existing one; you may have cracked out the solder joint or broken a trace on the board and it just coincided with this event. Easy fix if you can solder reasonably well; the odds of you actually damaging the amp IC are small.


Good hunting!


mnem
tssssssst!

 

Try a linux live cd or usb drive to make sure it's not software related.

 

I uninstalled the sound drivers, I downloaded the drivers for vista and installed them, I have W7 and I used very few drivers from Panasonic because most every thing worked, no joy with the driver change.

I have Ubuntu 12.04 installed on it as well, same problem, speakers both work, left phone output zero.

I can solder so I will take it apart to see what I can see......

There must be a switch because when you plug in the phones the speakers stop, so the speakers and headphones cannot simply be in parallel.

 

If I recall correctly, Sadlmkr had a strange sound issue with a cf29. I believe it was the headphone jack also. He could not get it to work until he used factory restore disk. From the service manual, it appears that the headphones and speakers have separate outputs on the audio chip. Maybe the chip senses the headphones and the switching is done electronically. From what I read, the sounds switches/controls/info are stored with the bios. Factory restore seems to reset them. A lot of people have had strange issues with CF 29 sound.

Searching for old threads.......


http://forum.notebookreview.com/panasonic/639422-i-thought-i-done.html#post8249326

http://forum.notebookreview.com/panasonic/635228-cf-29hwlgzbm-no-sound.html#post8196982

http://forum.notebookreview.com/panasonic/427022-cf-29-sound-speaker-issue.html#post5491179

http://forum.notebookreview.com/panasonic/537010-cf-29-lost-audio-output.html

 

How do I fix my broken audio-out jack? - Dell Inspiron 6000 - iFixit

This guy actually answered instead of saying "oh yeah mine does that too". kudos to the author.

Worth a try and I can tear a jack apart to see how they are built. Or Shawn could...he has an extra CF-74. I think there is a mechanical switch in the jack. Possibly jammed part way "closed"???? where it is disabling the one speaker.

I think you damaged the innards of the receptacle. (I never know what to call them...it's not the plug...must be the socket)

If all else fails I have a 74F ready to go.

A custom designed probe may be indicated also. I had one in the past to pull bearings from the 4wd on my F250. You might want a smaller one......I'm getting this from a conversation I with Teo several years ago..(PM) Read dental pick here. HEY! Driller. end edit

 

Some headphone jacks have switch contacts that make/break as the plug is inserted as shown in these:






Some just have contacts which touch the plug in the right way (shut up Rob, you prevert) to make the connection; but have no actual switch as the device monitors the change in impedance and knows what's been plugged in.




Under any circumstances, they're generally made to be as hard as possible to open up, and doing so usually breaks them. 30 years in the repair business has taught me to have a suitable replacement on-hand BEFORE I try and take the old one off; you often have to cut the legs off to get them off without destroying the printed circuit board they're soldered to. I recommend you learn from my mistakes.


mnem
zzzzt.

 

PM sent to OP on cf 74D motherboard.

 

Thanks for all the input, will be opening it up for a look this weekend. will decide what I will do soon.

 

I opened it up, nervously I might add. I used a known good set of headphones and checked continuity from the speaker leads though plug(s) to the solder joints that connect the receptacle to the motherboard, all circuits tested normal.

Problem must be in the motherboard, I could not see cracks on PCB from an impact or something, now I need to decide if I wand to live with it or not. In the scope of things it's quite minor, but I do use the jack for headphones and speakers quite often.