Only vertical lines are distorted and move slightly in an apparently repetitive rhythm
Bad Capacitors, particular check the seconrary polymer types, testing for leakage current, self-inductance and component quality.
Replace the bad capacitors to the correct types. Important:
Important to note that not every capacitor is suitable due to its key data and size. It is essential to ensure that the correct specification is used!
This is an unpleasant defect, because there can be several reasons for it. First of all you should check the power supply of the VSA100 chips. Test if the power supply still works on both channels. Check the ripple of the DC voltage on the secondary side of the power supply. This can only be determined with an oscilloscope and also please check, if the voltage on the primary side is ok.
Check if the two coils have a clean magnetic field spectrum. This can be seen very well with a spectrum analyzer and a HF-Probe.
Picture fails only at high resolutions and/or high frequencies
Too low voltage for the RAMs
Check the voltage for the RAM chips. It should have 3.3V. If not, repair power source.The voltage level in this case was to be found at a 300mV rippled 2.7VDC. Replacing the OP-Amp [AR1] and it’s FET [Q5] solved the problem.
Voodoo 5 5500 PCI Card kills the Mainboard after 3dfx BIOS flash attempt!
A defect Bios chip on the 3dfx card kills the bios chip on the mainboard during flashing the bios on the 3dfx card. After that the Mainboard posts only long beep and didn’t start any more.
Nuked BIOS Chip on the 3dfx card
The flash attempt chokes out the mainboard bios.
Replace and flash Bios Chip on 3dfx card
The Mainboard ain’t nuked too. Only replace Bios chip.