Dell 4100/200, 4100/180 manual Video Test Group

The System Set Test Group also verifies the proper oper- ation of other computer components, such as the speaker, that are not tested elsewhere in the diagnostics.

The following symptoms usually suggest a problem with a component or subassembly that warrants running a Sys- tem Set subtest:

•A program is not running as usual, or a proven piece of software appears to malfunction and you confirm that the software itself is not at fault. (You can con- firm that the software is functioning properly by moving it to another computer and running it there.)

•An option card you previously accessed can no longer be accessed.

•You get parity errors or page fault failures (any error message that contains the word parity or page fault) at any time during operation. These errors are usually accompanied by a reference to an address, which you should record on a copy of the Diagnostics Checklist found in Appendix A.

•Correcting errors in the system configuration infor- mation in the System Setup program does not resolve a problem.

•The computer’s clock/calendar stops.

•The speaker no longer functions. The problem could be a failure of the system timers as well as a failure of the speaker itself. Run the System Timers Test, followed by the System Speaker Test.

•If a peripheral device appears to malfunction, run the Interrupt Controllers Test.

•A spreadsheet program or other type of mathemat- ical application runs abnormally slow, generates error messages concerning calculations or opera- tions, runs incorrectly, or generates incorrect results, or a proven piece of the program appears to mal- function and you confirm that the software itself is not at fault. (You can confirm that the software is not at fault by moving the program to another computer and running it there.)

•The computer periodically locks up, especially at different places and times in different programs.

•The computer halts in the middle of performing cal- culations or complex mathematical operations.

Video Test Group

The subtests in the Video Test Group verify the proper operation of the video controller and the video control circuitry installed in the computer. These subtests check for the correct operation of the readable registers in the video circuitry and the controller. They write, read, and verify data patterns in the cursor registers of the control- ler. The Video Test Group also tests all the video memory and provides additional subtests to test the color features of a color monitor.

Subtests

The eight subtests in the Video Test Group and the video functions they confirm follow:

•Video Memory Test

Checks the read/write capability of video memory in various video modes.

•Video Hardware Test

Checks the cursor registers and the horizontal and vertical retrace bit registers in the video controller.

•Text Mode Character Test

Checks the video subsystem’s ability to present data in text modes.

•Text Mode Color Test

Checks the video subsystem’s ability to present color in text modes.

•Text Mode Pages Test

Checks the video subsystem’s ability to map and present all available video pages on the screen, one page at a time.

•Graphics Mode Test

Checks the video subsystem’s ability to present data and color in graphics modes.

•Color Palettes Test

Checks the video subsystem’s ability to display all of the available colors.

•Solid Colors Test

Checks the video subsystem’s ability to show screens full of solid colors. Allows you to check for missing color subpixels.

Running the System Diagnostics 5-13