ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ» º º º INTEL MATH COPROCESSOR HARDWARE TROUBLESHOOTING º º º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ 386 XENIX/UNIX AND THE 387DX ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ When 386(TM) versions of Xenix or Unix run on a computer containing an Intel 387DX math coprocessor, the computer can lockup intermittently. Read FaxBack document #3054 for more detailed information on this problem. 387DX & WEITEK SOCKETS ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ Many computers contain with a square socket for a Weitek math coprocessor. This socket has three rows of holes on all four sides. In many computers, such as the Compaq 386, the inner two rows of pins are compatible with the Intel 387DX. This gives you the option of using an 387DX or the Weitek math coprocessor. However, if you want to install an 387DX in the Weitek socket, you must use EXTREME CAUTION to orient the chip correctly; otherwise you could damage the computer and the 387DX. Read your computer's User Guide to determine the correct procedure for installing the 387DX in your computer. The Installation Guide for the 387DX contains general information which may be useful also. If you have trouble figuring out how to correctly install the chip, have your dealer perform the installation for you. Intel can't replace a part which has been destroyed by incorrect installation. Some computers use the Weitek socket but DO NOT support the 387DX, such as the TANDY 4000. Contact your computer manufacturer or dealer for more specific information. 387DX/MATH UNIT AND IBM ADVANCED DIAGNOSTICS ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ The 387DX and Inboard 80287 Math Module will fail the IBM Advanced Diagnostics. This happens because the diagnostics reinitialize the 387DX or Math Module after the Inboard 386 has already initialized it. Use the CHKCOP program on the Inboard 386 diskette to test an 387DX or Inboard math module. ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ 2/90 Intel FaxBack # 3062 Page 1 ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ» º º º INTEL MATH COPROCESSOR HARDWARE TROUBLESHOOTING º º º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ(continued)ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ BURNED PIN ON 387DX ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ The most common cause for burned pins on the 387DX is incorrect installation. In many computers, the 387DX is oriented differently from the other large chips. Carefully follow the manufacturer's installation instructions to avoid damaging the 387DX. The Intel warranty doesn't cover chips which were installed incorrectly. COMPAQ COMPUTER PROBLEMS ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ If, after adding an Intel product (such as INBOARD, ABOVE BOARD or Math Coprocessor), your COMPAQ 286 computer begins to reboot itself automatically, it is usually a symptom of one of two problems: þ The connection between the power supply and the system board could be defective. The computer will continue to operate until either an additional burden is placed on the power supply, or enough oxide builds up to cause the failure. The cure for this is to vigorously reseat the connection. Be careful to not apply excessive force and break the connector or system board. þ The power supply could be taxed beyond it's capabilities. The only solution for this problem is to replace the power supply with a bigger one. REMOVING 80287 FROM IBM PC AT ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ After removing a math coprocessor from an IBM PC AT computer, you must rerun your computer's SETUP program. If you still receive an error message because the computer can't find the chip, you may have to temporarily unplug the battery from the system board. All SETUP information will be lost, so be sure to write down the hard drive type, floppy drive type, memory and video configurations before unplugging the battery. This information is critical in correctly reconfiguring your computer. ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ 2/90 Intel FaxBack # 3062 Page 2 ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ» º º º INTEL MATH COPROCESSOR HARDWARE TROUBLESHOOTING º º º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ(continued)ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ REPLACEMENT 8088 ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ If you have an 8087 and a 4.77-MHz 8088 dated '78, you can get a free replacement 8088. Contact Intel Customer Support for the replacement. NOTE: Only 4.77-MHz 8088 chips need to upgraded. The 8088-2 and 8088- 1 do not require replacement. IBM PS/2 MODEL 80, 387DX & NOISE FROM SPEAKER ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ Some of the 8580 Models 111 and 311 with math coprocessors installed may experience trouble with the speaker. You may hear crackling or beeping noises while the computer is running. the 387DX doesn't cause this problem. The following computers may have the problem: þ 8580 Model 111, with serial numbers below 6019000 þ 8850 Model 311, with serial numbers below 6502022 ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ 2/90 Intel FaxBack # 3062 Page 3