On Mon, Apr 19, 2004 at 03:29:19AM -0800, Uwe Zimmermann enlightened us thusly > Hello Declan, > > Monday, April 19, 2004, 3:39:20 AM, you wrote: > > DM> On Sat, Apr 17, 2004 at 01:09:21PM -0800, George Mogiljansky > enlightened us thusly > >> Hello, For board-level repairs, what is a good website or > >> newsgroup? Briefly: My PowerBook 3400/180 hit the floor and now > >> boots from the internal IDE HDD only if a powered external SCSI > >> device (CD-Rom or HDD) is attached. I tried another internal HDD, > >> no change. Choice of OS doesn't matter. Both internal HDDs work > >> fine in another PowerBook. > >> > >> I can provide more detail, such as: "..the SCSI-bus has built-in > >> active termination..the SCSI port supports ANSI X3T9.2.." plus pin > >> assignments, etc. > >> > >> George > > DM> Put a 'scope on the bus and ckeck the logic levels. I'll bet they > are DM> borderline fail somewhere, and that extra drive is acting as a > pullup DM> or pull down, and making things borderline pass. > > But an internal IDE harddisk does not sit on the same bus as an > external SCSI device?!?!
OOOPS! Any Mac I opened had scsi internally. Are you sure it's ide internally? > > I would think that somehow the powered external device supplies the > internal device over the termination power line on the SCSI bus and > that some internal power connector, power cable or power trace broke > during the impact.... > > In this case check the 5V supply of the internal HDD and try to trace > it all the way back to the power converter. > > Uwe. > > -- Author: Uwe Zimmermann INET: [EMAIL PROTECTED] > > Fat City Hosting, San Diego, California -- http://www.fatcity.com > --------------------------------------------------------------------- > 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). -- With best Regards, Declan Moriarty. -- Author: Declan Moriarty INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- 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).
