I finally tried one of the most basic diagnostic steps I should have done almost first, since I have the parts to do so. I tried swapping the motherboard, lcd, & keyboard boards around with those from a good M100.
The motherboard of the dead M100 turns out to be fine. Whatever the problem is, it's in the display board. (I eliminated the keyboard too) On Sat, Dec 30, 2017 at 10:33 AM, Fugu ME100 <[email protected]> wrote: > I would hold off desoldering the SRAM modules until it is established > where the problem is located. It could be one of the buffers driving those > chips. I believe someone already mentioned they had an issue with a buffer > and had to replace it on their broken machine. > > The CPU looks like it is doing the right things now it is a matter of > tracing out the Address, data and control lines to make sure they are > arriving at the ROM and SRAM correctly. > > Since the machine was on battery power when the backup power was turn off > the SRAMs would of been powered down while still being driven by the > attached buffers. So they would of been driven in a unpowered state which > could of damaged their protection diodes causing a short or overloaded and > damaged a buffer. > > I was not aware of the different models I must have really early versions > as they only have 1 SRAM module soldered in the other three are socketed – > which is nice for debugging. :) Thanks for that information I keep > learning more about my machines. :) > > From: M100 <[email protected]> on behalf of Mauro Pintus < > [email protected]> > Reply-To: <[email protected]> > Date: Saturday, December 30, 2017 at 6:35 AM > To: <[email protected]> > Subject: Re: [M100] diagnose > > Yes, my Olivetti M10 has 3 soldered modules for a total of 24k plus a free > socket for the optional one (see linked pictures below). > > I'm gathering courage to desolder all the SRAMs and place a socket on the > first position hoping that at least one module is fine. > > Mauro > > > > Inviato da iPhone > > Il giorno Dec 30, 2017, alle ore 12:25, Jan Vanden Bossche < > [email protected]> ha scritto: > > AFAIK, he's working on an Olivetti M-10... > Nut, also AFAIK, the M-10 followed the same scheme as the M100. > > Greetings from the TyRannoSaurus > Jan-80 > > > ------------------------------ > *From:* Mike Stein <[email protected]> > *To:* [email protected] > *Sent:* Saturday, 30 December 2017, 6:53 > *Subject:* Re: [M100] diagnose > > They were different models: > 26-3801 M100, 8K + 24K optional > 26-3802 M100, 24K + 8K optional > 26-3803 T102, 24K + 8K optional > > m > > ----- Original Message ----- > *From:* Brian White <[email protected]> > *To:* [email protected] > *Sent:* Saturday, December 30, 2017 12:44 AM > *Subject:* Re: [M100] diagnose > > > > On Dec 29, 2017 11:53 PM, "Fugu ME100" <[email protected]> wrote: > > In the T102 and M100 there are SRAM modules that are plugged into sockets, > I am not familiar with the M10, but these modules are easy to remove from > the socket and do not need to be desoldered. > > > > That's not necessarily true. If a particular unit was sold with 8k, then > it has 1 module soldered, and 3 sockets. If a particular unit was sold with > 24k, then it has 3 soldered modules and 1 socket. Same is true for both > m100 and t102. > > He most likely has to desolder 3 modules. I definitely do. > -- > bkw > > > > -- bkw
