Headphones won't work, but speakers are fiine

I just had a clean install of Windows 7 on a new hard drive. All was fine until I decided to plug in headphones. Sound continued on the regular speakers, nothing on headphones. This happened again and again. I went to Sounds in Control Panel, checked Headphones, then inserted the plug again--and it worked--the only time since I got it back a week ago. I then made the error of disconnecting them. Once I plugged back in, again they wouldn't work. Rebooted a couple of times, with and without headphones plugged in, no headphones. The system didn't recognize that they were plugged in.

So, I went to Acer and downloaded the latest driver for this device, 64-bit, and installed it. Now the headphones don't even show up in the sound panel. I checked "Show disabled devices" and "Show disconnected devices", and headphones option still doesn't show up.

BTW, when I plug external speakers into the headphone plug, it gives a loud noise to let me know it's alive, but I still get no sound from the jack. I haven't rolled back the driver yet, seems to be no point, since it didn't work anyway, but I'm open to doing that.

Acer Aspire 5250-BZ852
Window 7 Home Premium 64-bit, SP-1, all updates in place

HIgh Definiton Audio device is the Windows installed, generic, basic function, sound drivers. They are not the correct hardware sound drivers.

Conexant audio is the correct drivers from what I can find. However, you need the drivers from Acer as drivers from another PC vendor (e.g. the HP you show) may not work or work properly.

Get the correct driver as the first step in resolving the problem.

Thanks. I guess that's what happens when you do clean installs on two different computers. My other is an HP.

I went to the Acer site but thought it recogned Aspire 5250, there was no listing for manuals or drivers. Apparently they don't support it anymore, even to the point of providing basic downloads. I did search but there are many, many sites listed and I'm not sure which to trust. Can you point me in the right direction?

I don't like any of the "driver sites". Many that say they have correct or updated drivers do not.
The generic High Definition audio driver may be the best you can do with an older PC. If Acer has a Vista driver it will work OK, but an XP driver is incompatible.

Although I said to use the vendor driver, since you have an HP with the Conexant driver, give it a try - may or may not work and depending on how HP setup the driver it may not install on a non-HP computer. But, set a system restore point first and the try the driver install. If it screws things up, the System Restore should get it back right.

The HP driver didn't work. The only driver listed for the Aspire 5250 on the Acer site is for windows 8 or 10. Maybe I'll just download the Win 8 and see if it works.

The Win 8 "might" work if its for Win 8 and NOT Win 8.1. If its Win 8.1 it won't work.

I've downloaded the autodetect. I'll let you know how that goes. Thanks.

Since I last posted, I've run autodetect, but no help there. I also downloaded from a driver site a driver for my Acer version, supposedly, but it didn't work either. I'm not sure where to go next. I know the headphones worked before the clean install, and they worked at least once since then, but except with the Windows driver, the headphones aren't even recognized as existing.

Still looking for a solution, since sometimes I'd really like to use headphones rather than speakers; and sometimes I'd like to use external speaker which plug into the jack.