No beep. At power-on, RESET_IN on the 80C85 goes from 0 to +5v and stays there steady. There is a 5mhz sine wave on X1, and a slightly squared 5mhz on X2, and a 2.5 mhz square on CLK out. some of the other pins have square 5v pulses.
All these chips have +5v on vcc (running on batteries) chip (pin#) 8085 (40) 8155 (40) 6402 (1) LH535618 (1) 6 x HM6117LFP (20) (the individual chips on the ram modules) One ram module socket empty Optrom socket empty Double checked I'm doing the blind beep motions exactly right by doing it on a good unit, then trying again on the bad unit. Thank you for giving me the excuse to finally pick up a scope. Got a rigol dso1054z and unlocked all the options except 500uv. I'm having fun playing with this thing. Guess I'll finally know how crap the sine wave is on my various UPS's. ;) -- bkw -- bkw On Mon, Nov 27, 2017 at 12:48 PM, Brian White <[email protected]> wrote: > Can-do. Thank you. > > -- > bkw > > On Nov 27, 2017 7:14 AM, "Josh Malone" <[email protected]> wrote: > >> I'd start with cold start, hit enter, type beep, enter, and see if the >> CPU and os is running. Assuming that they aren't, check the reset line with >> a scope to make sure the CPU is being reset properly on power up and that >> it's not held low (I think it's active low) since the nimh is in play on >> this one. >> >> Also check power supplies to the various chips. >> >> On Nov 27, 2017 12:34 AM, "Brian White" <[email protected]> wrote: >> >>> Ok, what do I look at first? >>> I don't suppose there is a common/frequent/likely answer to that? >>> >>> https://photos.app.goo.gl/3MXUjFmttEETro7m1 >>> >>> I notice the pattern of bars repeats. >>> >>> I have 2 other working 100's and this is a 3rd I didn't really want. I >>> got it as part of an ebay item where I wanted something else. The nicd was >>> just starting to corrode but hadn't yet leaked or anything. I've already >>> replaced it with a new nimh. >>> >>> I suppose it doesn't hurt to have a parts doner, but why not at least >>> take a shot at it eh? >>> >>> -- >>> bkw >>> >>>
