Path: wiretap.spies.com!sgiblab!swrinde!pipex!demon!hatstand.demon.co.uk!aaron Newsgroups: rec.games.video.arcade.collecting From: aaron@hatstand.demon.co.uk (Aaron Liddiment) References: <3dsu5p$p3c@nyx.cs.du.edu> Organization: Very Silly Party X-Newsreader: TIN [version 1.2 PL2] Subject: Re: DEFENDER diags help needed X-Posting-Host: hatstand.demon.co.uk Date: Tue, 3 Jan 1995 00:01:01 +0000 Message-ID: <9404052046.AA0005q@hatstand.demon.co.uk> Sender: usenet@demon.co.uk Lines: 106 David Fish (dfish@nyx.cs.du.edu) wrote: : The self test tells me that there is a failure and the four led's on the : ROM board display as shown below. My question is - what does it mean? : I'm guessing that it signifies a RAM error. Anyone know? Here are the self test extracts from the Defender booklet:- POWER-UP AND RAM/ROM TESTS ========================== Test initiated at power turn-on and after depressing RESET pushbutton on CPU/VIDEO board. RESULT CRT INDICATION LED INDICATION ----------------------------------------------------- Pass INITIAL TESTS OK 4 LEDs blink twice Fail Ram RAM TEST FAILED X--X (LEDs 1 & 4 light) Fail Rom ROM TEST FAILED None In either of the above two 'Fail' situations you should depress ADVANCE in MANUAL-DOWN while the failure message is displayed to enter Diagnostics. ROM DIAGNOSTICS - TEST 1 ======================== From game over, depress ADVANCE in MANUAL-DOWN. RESULT CRT INDICATION LED INDICATION CORRECTIVE ACTION ----------------------------------------------------------------- PASS ALL ROMS OK X--- n/a LED 1 blinks twice ----------------------------------------------------------------- FAIL ROM TEST FAILED X--- Replace ICX on ROM board X LED 1 lights or depress ADVANCE in (X = 1 to 12) MANUAL-DOWN. Chip indicated: Replace: ---X IC1 --X- IC2 --XX IC3 -X-- IC4 -X-X IC5 -XX- IC6 -XXX IC7 X--- IC8 X--X IC9 X-X- IC10 X-XX IC11 XX-- IC12 RAM DIAGNOSTICS - TEST 2 ======================== From ROM diagnostics depress ADVANCE in AUTO-UP. RESULT CRT INDICATION LED INDICATION CORRECTIVE ACTION ----------------------------------------------------------------------- TESTING Random Pattern n/a Depress ADVANCE in AUTO to bypass test ----------------------------------------------------------------------- PASS ALL RAMS OK -X-- n/a LED 2 blinks twice ----------------------------------------------------------------------- FAIL RAM FAILURE -X-- Replace RAM (see below) XY LED 2 Lights or depress ADVANCE in X=Bank No. MANUAL-DOWN Y=Chip No. -------------------------------------------- Bank indicated: Depress ADVANCE in X--- = 1 MANUAL-DOWN -X-- = 2 --X- = 3 -------------------------------------------- Replace in Bank: Chip indicated: 1 2 3 ---X = 1 4L 5L 6L --X- = 2 4M 5M 6M --XX = 3 4N 5N 6N -X-- = 4 4O 5O 6O -X-X = 5 4P 5P 6P -XX- = 6 4Q 5Q 6Q -XXX = 7 4R 5R 6R X--- = 8 4S 5S 6S CMOS RAM DIAGNOSTICS - TEST 3 ============================= From RAM diagnostics depress ADVANCE in AUTO-UP. RESULT CRT INDICATION LED INDICATION FAULTY AREA ------------------------------------------------------------------------- PASS CMOS RAM TEST PASSED --X- n/a LED 3 blinks twice ------------------------------------------------------------------------- FAIL CMOS RAM FAILURE --X- CMOS RAM 1I, LED 3 lights memory protect gates 2H, 1K or address decoder 2F, 4E. ---------------------------------------------------------------- CMOS INTERLOCK FAIL --X- Coin door interlock, LED 3 Lights memory protect gates 1J, 1K, 2H or CMOS RAM 1I. I hope these help you find your problem :-)