Siemens office box and ECS. Great picks! FYI, PCChips took over ECS in 1998, so its pretty much a pcchips with different logo.

>It seems to be power delivery problems through AGP slot?

Test continuity between ATX 3.3V pin and AGP 3.3V ones.

Good thought ! Yeah test the actual ohms from the ATX 3.3v to pins 9, 16, 28 or 45, those be 3.3v VCC. Then check again to 34, 40, 52 or 64., those be VDDQ and should be tied to 3.3v on AGP 2x board like a LX/BX.
On my one BX board just checked and are 0.0 ohm to the ATX 3.3v meaning a good set of traces to those power pins..anything more than a few 1/10 ohm would be a bad thing for a higher current drawing vid card (create a V. drop in the traces).
It also could be something else like a BIOS issue not initializing the video bios....

That might be the problem on/with ECS P6BXT-A+ Rev.: 2.2E. Others seem OK. But why Quadro2 Pro does not send signal at all to monitor on all those PCs? What makes 440BX/440LX incompatible with Quadro2 Pro but compatible with newer GPUs? Is Quadro2 Pro really more power hungry than my other GPUs?

Hmm the Quadro2 Pro uses a NV15 gpu variant which be similar as NV15 in the Geforce2 GTS, Ti and GF2 Ultra according to techpowerup. Hard to find any real power requirements other than "system PSU of 250watt or more"

Afaik Quadro and Ultra are using same pcb design with SC1175 regulators? Those are able to report brownouts. Its possible Quadro bios being more fancy actually monitors that.

Sephiroth, The Great wrote on 2024-05-18, 09:45:

Those motherboards are bad with the AGP GPUs compatibility and I don't know why people like them so much and consider them best […]
Show full quote

Those motherboards are bad with the AGP GPUs compatibility and I don't know why people like them so much and consider them best of all time. When it comes to AGP compatibility they are bad.
I tested 3 motherboards: 2 440BX (Siemens Nixdorf D1107 and ECS P6BXT-A+ Rev.: 2.2E) and 1 440LX (VL-601).
And on none of those motherboards can Quadro2 Pro send video signal to monitor on boot (but it sends video signal on boot with 775Dual-VSTA normally).
Other tested by me GPUs (GeForce4 Ti 4200 with AGP 8x, Quadro4 980 XGL 128Mb, Asus GeForce4 Ti 4800SE and 2 different FX 5900XTs) were OK (they sent video signal to monitor normally on boot) on Siemens Nixdorf D1107 and VL-601 (maybe one of GeForces FX 5900XT had a little trouble to fully light blue LED lights on its fan but that is it).
But when I tested those GPUs on ECS P6BXT-A+ Rev.: 2.2E the results were tragic with all those GPUs. When I booted the PC it sometimes sent video signal to monitor and sometimes not with all those GPUs. Once it sent video signal to monitor and other time not with all those GPUs. With GeForce FX 5900XT I observed that sometimes it booted with this GPU and lighted blue LEDs on its fan and sent video signal to monitor and other time it did not light those blue LEDs and did not send video signal to monitor and other time it did only light them for a few seconds and then turn them off and not send video signal to monitor.
So ECS P6BXT-A+ Rev.: 2.2E is definitely the worst one.
It seems to be power delivery problems through AGP slot? It is definitely not a problem with a PSU. I tried and swapped a few different powerful PSUs and results are always exactly the same. Those motherboards have that poor power delivery through AGP slot? Quadro2 Pro is more power hungry/demanding than all those other newer GPUs?

Perhaps it's those specific boards you are using.

The various Asus 440BX boards I have all work reliably with FX and GF4 series cards. I also have a Tyan slot 1 board that works with the same cards and a micro-atx ECS slot-1 BX board that works reliably with an FX5900XT too.

I have several FX5900XT cards, a Quadro FX3000 and a number of FX5700 and under cards, also TI-4200 and numerous older geforce cards.

pete8475 wrote on 2024-05-20, 00:21:

Perhaps it's those specific boards you are using. […]
Show full quote

Sephiroth, The Great wrote on 2024-05-18, 09:45:

Those motherboards are bad with the AGP GPUs compatibility and I don't know why people like them so much and consider them best […]
Show full quote

Those motherboards are bad with the AGP GPUs compatibility and I don't know why people like them so much and consider them best of all time. When it comes to AGP compatibility they are bad.
I tested 3 motherboards: 2 440BX (Siemens Nixdorf D1107 and ECS P6BXT-A+ Rev.: 2.2E) and 1 440LX (VL-601).
And on none of those motherboards can Quadro2 Pro send video signal to monitor on boot (but it sends video signal on boot with 775Dual-VSTA normally).
Other tested by me GPUs (GeForce4 Ti 4200 with AGP 8x, Quadro4 980 XGL 128Mb, Asus GeForce4 Ti 4800SE and 2 different FX 5900XTs) were OK (they sent video signal to monitor normally on boot) on Siemens Nixdorf D1107 and VL-601 (maybe one of GeForces FX 5900XT had a little trouble to fully light blue LED lights on its fan but that is it).
But when I tested those GPUs on ECS P6BXT-A+ Rev.: 2.2E the results were tragic with all those GPUs. When I booted the PC it sometimes sent video signal to monitor and sometimes not with all those GPUs. Once it sent video signal to monitor and other time not with all those GPUs. With GeForce FX 5900XT I observed that sometimes it booted with this GPU and lighted blue LEDs on its fan and sent video signal to monitor and other time it did not light those blue LEDs and did not send video signal to monitor and other time it did only light them for a few seconds and then turn them off and not send video signal to monitor.
So ECS P6BXT-A+ Rev.: 2.2E is definitely the worst one.
It seems to be power delivery problems through AGP slot? It is definitely not a problem with a PSU. I tried and swapped a few different powerful PSUs and results are always exactly the same. Those motherboards have that poor power delivery through AGP slot? Quadro2 Pro is more power hungry/demanding than all those other newer GPUs?

Perhaps it's those specific boards you are using.

The various Asus 440BX boards I have all work reliably with FX and GF4 series cards. I also have a Tyan slot 1 board that works with the same cards and a micro-atx ECS slot-1 BX board that works reliably with an FX5900XT too.

I have several FX5900XT cards, a Quadro FX3000 and a number of FX5700 and under cards, also TI-4200 and numerous older geforce cards.

I have similar experience. Like I stated in first post here all my NV28 (including Quadro4 980 XGL) and NV3x GPUs seem to also work OK on those motherboards except ECS P6BXT-A+ Rev.: 2.2E (which is probably faulty someway/somehow).
But Quadro2 Pro does not send video signal to monitor on any of those motherboards. But otherwise Quadro2 Pro works perfectly fine on 775Dual-VSTA.