14 Jun
2007
14 Jun
'07
12:11 p.m.
> 1820-2075 = 74LS245 (that has 20 pins, surely)
> 1826-0210 = LM361
> 1820-1197 = 74LS00
> 1820-1216 = 74LS138
> 1820-1202 = 74LS10
> 1820-1112 = 74LS74
> 1820-1422 = 74LS122
> 1820-2058 = MC3448L (HPIB buffer chip)
> 1820-0325.= MC815P
Note the correction to the last one (it's a 1810-xxxx, and is a resistor
arry) in my other message.
Wow!!!! Thank you!!
This really simplify the task to understand what's wrong and replace a chip
if needed.
I'm just curious about two things:
first, are this hp house codes generic (i.e. valid for any product), or are
YEs, they are. They're HP part numbers. In a very few cases the same chip
got assigned 2 different part numbers, but in general, the same number
was used company-wide.
they related to this controller only?
second, where do you find these valuable informations?!?!? ;-))
I have a long, poorly-copied equivalents list that covers most of them.
Other s I have found out by seeing chips marked with both numbers. HP
service manuals which include component-level info are another useful source.
I've checked almost all points in the circuit, and
I didn't find any -Ve
supply. Also, PSU only gives +5 and +12 volt.
Yes, but if the -ve supply circuit
has failed, you won't find it :-) I am pretty sure I have one of these, or something
closely related. If
you get stuck, I can be convinced to find it, pull the covers and do some
tests.
Ok, I'll let you know. In the meantime, maybe I've found a complete
service manual for the drive.
I'm waiting for it.
I would be suprised, alas, if it contains scheamtics :-(. Most later HP
computer product service manaulas are, alas, boardswapper guides.
-tony