Oops ;-) I'd meant to ask whether you'd checked the various voltages on the display board (Vdd, V2, 3, 4, 5, 6, Vee).
m ----- Original Message ----- From: Brian White To: [email protected] Sent: Tuesday, January 23, 2018 3:22 AM Subject: Re: [M100] diagnose Well I don't know what I'm looking yet, but it's fun playing with the analyzer. I rigged up a breakout for the lcd cable, passing all signals through normally, and tapping some for the analyzer. Started by tapping AD0-AD7 and PA0-PA7. Both these pics are the same motherboard from the bad unit. One with a good lcd board, one with the bad lcd board it came with. bad lcd https://photos.app.goo.gl/4QDlMt1YbEd6pQbl1 good lcd https://photos.app.goo.gl/fpF9cxmsRVeueMUy2 good times https://photos.app.goo.gl/QLV1mZsNqsu4eXkA2 On Sun, Jan 21, 2018 at 1:05 AM, Brian White <[email protected]> wrote: 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 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 -- bkw
