Hello Declan, As far as I know, 48Z02 is a zero-power SRAM with Li battery built-in, GM76C88AL-12 is a SRAM and 68HC11 have an internal A/D 8bit converter and 8 analog inputs. I don�t think this A/D is precise enough for this application so it might be another A/D chip on board (?). Not a bad idea to look for a supply failure, maybe one voltage is missing since you have same alarm on all channels. I hope this will help you a bit.
All the best, Mircea Coman --- Declan Moriarty <[EMAIL PROTECTED]> wrote: > I have a 3 channel chart recorder for repair. The > problem is an error > '9999.9 - ADFAIL' comes up on all three channels. At > the heart of each > is a 28 pin plcc chip. It says > <logo> TIP > 9924NCC > C17619 > 120S1355 > REV 01 > > The logo is a smallish 'M' in a circle, but it's a > very plain 'M', not > reminiscent of Motorola or Maxim, who use slightly > fancy 'M' in their > logos. There is three of the above chips. The cpu is > separate. > > Google returns rubbish, of course. > > It's about 5 years old, and I suspected a power > supply, but all seems > good. It's a bit difficult to tell, because the > circuit has loads of > little 78Lxx and low power lm317s in strange places > and is inclined to > dissappear up it's own backside when you try and > follow it ;-). All the > other stuff is Common enough (National/ST parts) and > the transistors are > pro electron, so we appear safe from inscrutable > Far Eastern devices. > > The other bits on each channel (taking a variety of > temp probes) are a > 93LC66 (serial eprom) LM324, LM393, & some > optocouplers. There isn't a > databus going off either. Serial? > > Nothing that looks like an a/d on the main board. A > Mostek(!)48Z02 and a > Goldstar(That's an Irish meat company!) GM76C88AL-12 > are the only things > beside logic, and the cpu, which is a 68HC11. > > Any ideas welcome. > > -- > > With best Regards, > > > Declan Moriarty. > -- > Author: Declan Moriarty > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 > http://www.fatcity.com > San Diego, California -- Mailing list and web > hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an > E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of > 'ListGuru') and in > the message BODY, include a line containing: UNSUB > CHIPDIR-L > (or the name of mailing list you want to be removed > from). You may > also send the HELP command for other information > (like subscribing). __________________________________ Do you Yahoo!? Protect your identity with Yahoo! Mail AddressGuard http://antispam.yahoo.com/whatsnewfree -- Author: Mircea Coman INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
