CCPN@latvax8.lat.oz (Paul Nankervis) (02/23/90)
I have a RAINBOW 100B which fails to boot. It displays ERROR 18 and has all the diagnostic lights on except 5 & 6. I have a set of RAINBOW 100A documentation which says that this is a Z80 CRC error. Does anyone know what causes this error (eg Z80, RAM, ROM, etc), or do I have to throw away the motherboard? Paul Nankervis CCPN@LATVAX8.LAT.OZ La Trobe University Australia
iav1917%ritcv@cs.rit.edu (alan i. vymetalik) (02/23/90)
In article <359@latvax8.lat.oz> CCPN@latvax8.lat.oz (Paul Nankervis) writes: >I have a RAINBOW 100B which fails to boot. It displays ERROR 18 >and has all the diagnostic lights on except 5 & 6. I have a set >of RAINBOW 100A documentation which says that this is a Z80 CRC >error. Does anyone know what causes this error (eg Z80, RAM, ROM, etc), >or do I have to throw away the motherboard? > >Paul Nankervis >CCPN@LATVAX8.LAT.OZ >La Trobe University >Australia Yikes! I've never seen this error before and I've seen a bunch of them, including a blown-up motherboard. I checked my doc set for the 100B (The Technical Manual Addendum) and you're correct on the error code. How often does it appear? Have you turned off/on the Rainbow, let it sit off, and then test boot it again? Does it ever boot up all the way? It it ever boots up, do you have any diagnostic software that you can run? Suggestion: If you feel comfortable with electronics, I would suggest removing the motherboard, clean away dust by blowing and wiping with an anti-static electronic cleaning brush (or air spray can). Then check to make sure that all chips (especially around the Z80 CPU) including the Z80 are properly seated. You may want to partially remove the Z80 chip and reseat it. Oxidation may have set in and a bad contact is occuring on the pins. If it still fails after cleaning and reseating everything and connecting it back up, then you're going to need service because one or more chips have failed. You'd need an oscilliscope and schematics to track it down. I'm surprised that a 100B board has died. Most of the dead ones I've dealt with were 100As. Good luck. Enjoy, alan -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Alan I. Vymetalik, 2244 East Avenue #5, Rochester, New York, 14610-2518 USA, Phone: (716)-271-8528 ...!rochester!ritcv!iav1917 -or- ...!rochester!rit!ritcv!iav1917 ritcv!iav1917@rochester.UUCP -or- iav1917%ritcv@cs.rit.edu /If I can't be reached via any of the above e-paths, please write./ =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Frank.Mallory@f123.n109.z1.fidonet.org (Frank Mallory) (02/25/90)
PN> I have a RAINBOW 100B which fails to boot. It displays ERROR 18
PN> and has all the diagnostic lights on except 5 & 6. I have a set
PN> of RAINBOW 100A documentation which says that this is a Z80 CRC
PN> error. Does anyone know what causes this error (eg Z80, RAM, ROM, etc),
PN> or do I have to throw away the motherboard?
Take out the system board and loosen and reseat all the socketed chips. Also,
check the flat cable between the power supply and system board for burnt
(dark) connectors.
frank.mallory@blkcat.fidonet.org
--
Frank Mallory at The Black Cat's Shack (Fidonet 1:109/401)
Internet: Frank.Mallory@f123.n109.z1.fidonet.org
UUCP: ...!uunet!blkcat!123!Frank.MalloryCCPN@latvax8.lat.oz (Paul Nankervis) (02/27/90)
> How often does it appear? Have you turned off/on the Rainbow, let > it sit off, and then test boot it again? Does it ever boot up all > the way? It it ever boots up, do you have any diagnostic software > that you can run? Whatever it is the error is hard on. I tried the board in a 100A to test power supply, cables and RX50 controller but I still have the problem. I have swapped the Z80 chip and checked for any obvious board defects. I was thinking that there may be a RAM problem when I realised that there is a separate message to cover that. It must be either the unshared RAM (unlikely as it is static RAM), access to the shared RAM, or the ROM code copied into shared RAM is corrupt (when copied from ROM). I was wondering if anyone has access to the PC100 firmware code and could tell me what is happenning when the error occurs (all lights on except 5 & 6). I may try borrowing a set of ROMs from somewhere to see if that is the problem. It would be great to have this system up and going again. Thanks in advance Paul Nankervis La Trobe University, Australia CCPN@latvax8.lat.oz