GX620, Windows 10, sound not working

Your XP model is too old to run windows 10. There are no dell drivers available for Win 10--especially the chipset you need.

https://www.dell.com/support/home/us/en/04/product-support/product/optiplex-gx620/drivers

This thread is the perfect @speedstep question.  Something I was told by speedstep in my wanting to switch from Win7 to Win10 on my 755 MT:  "There are no issues whatsoever but windows 7 8 and 10 are not supported. This doesn't mean it does not work only that its not supported."  If I remember right from his posts, speedstep also has a GX620 and I'm sure it's running something newer than XP.

If a GX620 can run Win10 and have correct audio drivers, speedstep will know for sure.

GX620 with BIOS A11 and Pentium D915 works FINE for EVERYTHING with MSDOS all the way thru Windows 10. Max Ram is 3.50 gigs regardless of 32 or 64 bit OS or video card. This is a chipset limitation. There are no windows 10 drivers for this system.  There are however VISTA and WIN7 drivers. The onboard INTEL Video and Soundmax Audio must come from dell. Everything else is native to windows 10.

DO NOT GO ANYWHERE other than DELL to get the drivers.

EDIT: the drivers Directly from microsoft are fine

http://www.catalog.update.microsoft.com/Search.aspx?q=analog%20devices

https://www.youtube.com/watch?v=PMO1AE8QoNU

Description	Download
ATI 256MB RADEON X850 XT Platinum Edition, Hyper Memory PCI-Express X16 (DVI/VGA/TV out) Radeon X300 SE, 128MB Radeon X600 SE, RADEON® X600 256MB HYPERMEMORY, 256MB Radeon X600, Radeon X1900XTX 512MB, X1300 Pro 256MB, X1300, X1300 Pro, v.8.36-070314a3-045812E-Dell.2-Vista32, A03 8.36 Vista 32 bit DriverMore details
ATI 256MB RADEON X850 XT Platinum Edition, Hyper Memory PCI-Express X16 (DVI/VGA/TV out) Radeon X300 SE, 128MB Radeon X600 SE, RADEON® X600 256MB HYPERMEMORY, 256MB Radeon X600, Radeon X1900XTX 512MB, X1300 Pro 256MB, X1300, X1300 Pro, v.8.36-070314a3-045972E-Dell-Vista64, A03 8.36 Vista 64bit driverMore details
Intel 82945G Express Chipset Family, v.7.14.10.1114, A00 VIDEO This package provides the Intel 945G Graphics controllers Driver and is supported on Optiplex GX520/GX620 and Dimension Desktop 5100/5100C/5150C/E510 Vista, 64-bit.More details
Intel 82945G Express Chipset Family, v.7.14.10.1114, A00 32 Bit Vista graphics driver for Intel 945G Graphics controllers.More details

Description	Version	Download
Dell Optiplex GX620/GX520 System BIOS This package provides the Dell System BIOS Update and is supported on Dell Optiplex GX620/GX520 for Windows and DOS Operating Systems.More details	A11
Dell Optiplex GX520/GX620 System BIOS This package provides the Dell System BIOS Update and is supported on OptiPlex GX520/GX620 running the following Operating Systems: Windows and DOS.More details	A10
Dell OptiPlex System BIOS, A08 Dell OptiPlex GX620 A08 System BIOSMore details	A08
Dell OptiPlex System BIOS, A07 Dell OptiPlex GX620 A07 System BIOSMore details	A07
Dell OptiPlex System BIOS, A06 OptiPlex GX620/GX520 A06 System BIOSMore details	A06
Dell OptiPlex System BIOS, A05 OptiPlex GX620/GX520 A05 System BIOSMore details	A05
Dell OptiPlex System BIOS, A03 OptiPlex GX620 / GX520 System BIOSMore details	A03
Dell OptiPlex System BIOS, A01 OptiPlex GX620 / GX520 Flash BIOSMore details	A01

Audio Drivers

Description	Download
Analog Devices ADI 198x Integrated Audio, v.5.12.2.7010, A02 This package provides the Analog Devices ADI 198x Integrated Audio Driver and is supported on Optiplex GX280/GX520/GX620/SX280 and Precision 370/470/670 Vista, 64-bit .More details
Analog Devices ADI 198x Integrated Audio, v.5.12.01.7010, A25 ADI Onboard Sound Driver Vista, 32-bit More details

Once you install Chipset and OEM audio driver and INTEL video driver everything works as you would expect.  Only restriction is 32 bit vs 64 bit.

If you do not have Pentium D 900 Series Pressler you must use 32 bit windows 10.  This restriction does not exist with windows 8.0 but does with windows 8.1.

See previous posts or even the GX620 faq from the really old forum.

https://www.dell.com/community/Desktops-General-Read-Only/DELL-OptiPlex-GX620-FAQ-Frequently-Asked-and-answered-Questions/td-p/2528727

XP VISTA 7 8 10 work fine on a 620 no matter which SIZE you have.

GX620 Models MR SMITH, Trinity, ETC

If you have no money but need a computer UBUNTU 18.04.2 also works fine .

http://releases.ubuntu.com/18.04/ubuntu-18.04.2-desktop-amd64.iso

@speedstep Thank you for your replies and thoroughness.  I attempted to install the chipset drivers you included in your post.  It did not install, said not support by OS.  I have 64-bit Windows 10 home.  I tried using every compatibility mode from XP SP3 to Windows 8 to no avail.  I also tried to install the driver manually through device manager.  Everything works on the PC except for the sound.  The sound did work in Windows 7 before installing Windows 10 so I don't believe it's a hardware issue.

dotnet 2.0 and 3.5 are required

once the oem driver is installed it finds the sound via device manager

I linked the windows 10 drivers below. 

The installer must be run as administrator.

DirectX June 2010 is also Highly Recommended.

Download DirectX Redist (June 2010) from Official Microsoft ...

Download file, Extract to a folder,  RUN DXSETUP.EXE as Administrator.

The Analog Devices AD198X codec does have WHQL drivers from the Microsoft Catalog.

microsoft catalog Analog Devices 5.12.1.7010   32 BIT

R145551.EXE         32 BIT

catalog.update.microsoft.com/.../ScopedViewRedirect.aspx

microsoft catalog Analog Devices 5.12.2.7010   64 BIT

R145149.EXE          64 BIT

catalog.update.microsoft.com/.../ScopedViewRedirect.aspx

How do I tell if the chipset is installed? I enables dotnet 2.0 and 3.5.  I ran the chipset installer.  It said it installed the chipset but I still do not have sound and there is still no driver for the multimedia audio controller.  I did restart the computer and looked for updates but it found none.

Is onboard audio turned off in bios?

If there are any sound cards installed in slots remove them.

I still have my 620 and every aspect of it including sound works fine with windows 7 or 8 or 10.

I have a Dell OEM drivers disk for 755 MT running Win10.  Select Drivers tab on top.  On the left side of screen, select "All" for OS of it doesn't show Win10.  Checkmarks will be by the appropriate drivers to click on and load.  The audio driver will be SoindMax.

Edit:  This doesn't mean get a 755 OEM drivers disk.  The suggestion's intent was get a GX620 drivers disk.  I thought this was understood, but can see how the wording wasn't exact enough.

A fake drivers disk will only take you to the Dell site at best.

This is not meant to over-simplify if there's still a chipset issue.

I can't remember if it was mentioned - Dell Support Assist will also show appropriate drivers.  "Drivers & Downloads" link is always below the last post with other links.  I also reviewed and noticed quite a few links were given.

How's the CMOS battery?  Lifespan is aroind 5 yrs. and the GX620 is from 2006.  A low battery will cause all sorts of bizarre problems.  Lithium is recommended if it's due for replacement.

I'm hoping this isn't a case of too many download attempts.  One AIO I had - the sound didn't work.  But I also wasn't sure if it was too many attempts at different drivers.  In which case, I would've had to reload the OS for a clean slate.

I can tell you're having a hard time so hopefully this helps.

OEM drivers disk for 755 MT are not appropriate for GX620.

Neither the Audio nor INTEL Graphics Driver are the same or compatible.

Neither Model Comes with Windows 10 Drivers.

That is not and has never been an issue however.

Vista or WIN7 drivers 32 or 64 bit work fine.

32 bit windows is required for CPU that is older than Pentium D 915 aka Pentium D 820 for example.

Ram is 3.5 gigs max regardless.

This is a limitation of the chipset.

If you want to use 8 gigs get a Precision 380. That model does not have onboard INTEL graphics stealing ram. 

All the parts RAM, CPU, Drives etc from a GX620 will work in a Precision 380.

the MS server has it. but sound max takes 2 driver, one from intel and one from dell (analog devices)

it  found this at the PNP servers, top of list.

http://www.catalog.update.microsoft.com/Search.aspx?q=analog%20devices

seen next post for the Microsoft cure, that almost works,  does but updates kill the drivers later.

I made an edit in the post @speedstep is referring to:

This doesn't mean get a 755 OEM drivers disk.  The suggestion's intent was get a GX620 drivers disk.  I thought this was understood, but can see how the wording wasn't exact enough.

I said I have a 755 drivers disk, but didn't say go buy one.

The sound is working.  I got an inexpensive sound card.  I'm not sure why I couldn't get the onboard sound to work.  I sincerely appreciate everyone's efforts to help me.  Thank you.

it is a complex issue, and documented already at guess where, MS.

yes the driver works but will fail at every w10 update.

every "Semi-Annual Channel" update  it will fail. so you reload it at that moment.

see post by bu11etpr00f below.

kudos to HIM.  soundmax, 198x drivers takes 2 loads, the intel part works in conjuction with the Analog devices chip in complex ways, only DELL knows how, ok>?

https://answers.microsoft.com/en-us/windows/forum/windows_10-hardware/soundmax-driver-kills-fall-creators-update/4673ab2d-81bf-4096-857e-5c4ce843a0be

the dell main page shows no such driver, that IS BECAUSE the PC is not fully W10 certified,

so DELL shows no w10 support gx620 page, but does not state (w10 soundmax may work partly with this driver)

it does not say XP only and a sub title "some drivers for W10 do work half way",,,,, gee, why do that?

the OP there said:

Dell driver update package R297329 ARE working.  (a secret driver buried, and for good reasons)

W10 is forever, so now with that game played, now W10 really is REALLY

1507,1511,1607,1703,1709,1803,1809,,,

what will happen each time is anyones guess.

or say I run windows 1809,64bit.  a brave new world.

yes and even a $4 sound dongle fixes it. yes, 

in fact many w10  failures can be cured that why with cheap replacement that is w10 certified,

GPU cards

PCI cards

sound , video, . even CPU upgrades can work (Pentium to core i-3 if you have core mobo)

on the old intel HD GPU chips (not supported by Intel) we set BIOS to GPU off and install  a nice GTX card.