Thats a weird Solo-1, looks like its from a proprietary OEM system as non OEM versions are much larger with considerably more components.

Me thinks it is a low profile OEM version too. Probably needs a driver installed prior to inserting OR the OEM OS package already had the driver included... just a guess
What OS are you trying to install it too ? From quick search Win9x and XP should be supported: https://www.driverguide.com/driver/detail.php … driverid=144136

Horun wrote on 2022-10-30, 05:51:

Me thinks it is a low profile OEM version too. Probably needs a driver installed prior to inserting OR the OEM OS package already had the driver included... just a guess
What OS are you trying to install it too ? From quick search Win9x and XP should be supported: https://www.driverguide.com/driver/detail.php … driverid=144136

Its possible that if it is a OEM special model then whatever system it came from may have the missing componentry embedded on the motherboard.

I have never actually seen a Solo-1 this integrated before, its also an odd number too most if not all Solo-1s are 1938s models, its very likely a custom job on top of being OEM.

https://www.majorgeeks.com/files/detail ... 1969).html

Found this archive of 1938/1946 drivers, seems to cover everything from Win3.11 to XP, perhaps one of these will work.

These are new cards with reclaimed chips (and questionable implementations). Lots of them on ebay/ali. Many with CMedia chips too. Much like all those new Rage XL cards.

Pierre32 wrote on 2022-10-30, 06:12:

These are new cards with reclaimed chips (and questionable implementations). Lots of them on ebay/ali. Many with CMedia chips too. Much like all those new Rage XL cards.

China ESS.jpg

might explain why old drivers wont work with them.

The ESS Solo-1E was marketed as a chip for laptops. I guess the "E" stands for "Embedded". I looked at the datasheets between the ES1938 and the ES1946, and found them to be pin-compatible. I don't know what else is different about them.

I bought these from a Chinese seller on eBay and got a mix between Solo-1E and Allegro-1E. The output from them is not great, and some of them had garbled audio or were dead. Others that were dead started working again later, so I can't speak for their reliability. Some of them were also damaged; one had a broken SMD capacitor, and another had a bent pin on the QFP that was shorting against itz neighbor.

I had problems trying to use these with VXD drivers, as they would cause my system to lock up. They worked with the WDM drivers though, but this loses Adlib/ESFM in Windows, at which point you may as well use an Ensoniq or Creative.

I salvaged a genuine ES1938 from a dead motherboard that I'm going to try swapping onto one of all else fails to see if this will bring it back to life.

If anyone plans to buy these, my recommendation is to to buy a bunch of them, to sort through the broken ones, and hope for a Solo-1 amongst the Allegros. But at that point you may as well have bought a proper Solo-1 from another seller. Also note that you also lose the gameport option on these.

This one is already dead, so I have nothing to lose by trying to fix it.

See attached for the two datasheets.

I can't tell if C22 and C24 are in series with the output or connected to ground. I hope they're in series because there will be a DC offset on the ESS chip's output. The op-amp circuit (U4) looks a little weird as well because it appears to be configured for a split supply. I guess it's using +12V and -12V, but that's kind of weird. For the distorted sound, you can check the voltage on each pin of U4 to see if the DC levels are correct.

The 78L05 is for the analog supply, so it probably won't cause the card to not be detected. If you want to check it, just measure voltage with your multimeter while the card is in the computer. You should see 12V on one of the outer pins and 5V on the other. There are two different pinouts for a 78L05 for some reason, but the center pin is always ground.

My first thought for the card not being detected would be to check the soldering on the ESS chip. You can gently touch the pins with something thin and see if they move.

I carefully cleaned and reflowed all of the pins on the QFP and there was no change. I ordered a couple of replacement OP-AMPs, to see if swapping that out will help.

I suspect that this one may be dead. The condition of the chips on some of the other boards is questionable.

The op-amp won't cause this problem, but it might cause the distorted sound from one of your other cards. This card also needs 3.3V from the PCI slot, but if you tested all of those cards on the same motherboard, that won't be the problem. I also think the ESS chip is dead.