ruslan@uncecs.edu (Robin C. LaPasha) (10/25/90)
A friend requests help - Situation: 1. Friend (accidentally) plugged in a printer cable (parallel port) AFTER powering up his Amiga 2500/30. (He DID know better, but had the power switch toggled the wrong way...) 2. It immediately gurued (number unknown) and now won't boot. (It goes dark screen-light gray screen-white screen and then stops, hangs.) ;^( 3. So, he probably fried a chip. Question: Which chip or chips did he probably fry, and how can we fix things? (We have folks with soldering, chip-pulling, and multitesting experience. ;^)) Can anyone offer part names/numbers of the probable offender(s), suggested test routines, average prices to expect to pay for parts? Thanks in advance. -- Robin LaPasha |Keeper of the Amiga ruslan@ecsvax.uncecs.edu |Hypermedia Mailing List
jms@tardis.Tymnet.COM (Joe Smith) (10/26/90)
In article <1990Oct24.193736.18642@uncecs.edu> ruslan@uncecs.edu (Robin C. LaPasha) writes: > 1. Friend (accidentally) plugged in a printer cable (parallel port) >AFTER powering up his Amiga 2500/30. (He DID know better, but had the >power switch toggled the wrong way...) Now it won't boot. >(It goes dark screen-light gray screen-white screen and then stops, hangs.) Pins 1-9 of the parallel port go to CIAA. This 8250 chip (at position U300) also reads 4 input signals from the floppy port. Pins 10-13 of the parallel port go to CIAB. This 8250 chip (at position U301) controls the serial port and 8 output signals to the floppy port. Your friend probably needs to replace both 8250's. They are semi-custom chips; get them from an Amiga dealer or Commodore. -- Joe Smith (408)922-6220 | SMTP: jms@tardis.tymnet.com or jms@gemini.tymnet.com BT Tymnet Tech Services | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms PO Box 49019, MS-C41 | BIX: smithjoe | 12 PDP-10s still running! "POPJ P," San Jose, CA 95161-9019 | humorous dislaimer: "My Amiga 3000 speaks for me."
david@starsoft.UUCP (Dave Lowrey) (10/26/90)
>In article <1990Oct24.193736.18642@uncecs.edu> ruslan@uncecs.edu (Robin C. LaPasha) writes: > >A friend requests help - > >Situation: > > 1. Friend (accidentally) plugged in a printer cable (parallel port) >AFTER powering up his Amiga 2500/30. (He DID know better, but had the >power switch toggled the wrong way...) > > 2. It immediately gurued (number unknown) and now won't boot. >(It goes dark screen-light gray screen-white screen and then stops, hangs.) >;^( > > 3. So, he probably fried a chip. > >Question: > > Which chip or chips did he probably fry, and how can we fix things? >(We have folks with soldering, chip-pulling, and multitesting experience. ;^)) > Most likely he fried one of trhe 8520 CIA chips. Try swapping the chips (they are socketed). If your problem goes away, or changes, then replace the chip(s). They cost around $20.00 each. -- ---------------------------------------------------------------------------- These words be mine. The company doesn't care, because I am the company! :-) Dave Lowrey | david@starsoft or {uhnix1,moray}!starsoft!david Starbound Software Group | Houston, TX | "Dare to be stupid!" -- Weird Al Yankovic
ruslan@uncecs.edu (Robin C. LaPasha) (10/29/90)
The unanimous advice from you net.gurus.of.wisdom is that the 8520 chips have blown. They are on order; we find out Wednesday night if it works... Thanks for all the replies. Robin -- Robin LaPasha |Keeper of the Amiga ruslan@ecsvax.uncecs.edu |Hypermedia Mailing List