IBM PC Radio Machine Type 9075
Posted by reggieiscrap@reddit | vintagecomputing | View on Reddit | 18 comments
So.. after having this 30 year old PC radio laptop sitting in a box for over a decade.. I finally got it to turn on using a stepdown transformer ( I'm in Australia at 220V AC)
This device was way ahead of its time.. this is early 1990s.. essentially leveraging a radio network invented by Motorola to allow remote access from pretty much anywhere that had access to a radio tower.. suffice to say it didn't take off.
I have an extensive IBM Announce letter describing form and function of the device.. and I have found the Wikipedia entry and the IBM PC Radio YouTube demo
Here is an article from the LA times in 1990 describing the technology
https://www.latimes.com/archives/la-xpm-1990-01-31-fi-1066-story.html
As you can see LCD is not functional.. but it lives.. sort of.. I suspect it will definitely require a clock battery..
Essentially I am chasing the user guide and maintenance manual if anyone can locate it I'd be keen to continue to see if anything further can be done to resurrect this ancient hardware..
IBM archive has little.. and my searches have come to naught..
Hope this is of interest and maybe someone can provide links to resources
solidpro99@reddit
The LCD is easy to repair. See my blog here where I fixed the LCD and built a power connector: https://ret.rocks/index.php/early-portables/ibm-pcradio
reggieiscrap@reddit (OP)
Best news I've had in 10 years ! where have you been all my life !.. I knew it was the caps.. I bought all the kit SMD heater .. flux, heat protecting tape, the lot. and chickened out as I cant eff this up.. would love to have a chat if thats a possibility.. and thank you
solidpro99@reddit
Sure. I had two machines and both had the exact same issue. Those 4 surface mounted caps are the issue. Lid is easy to remove as long as you remember there are two hidden screws behind the printer cover.
solidpro99@reddit
I just got one of these. I can’t seem to work out what you would use as a power supply and what connector is for powering it up? The one on the right is for a handset and the one on the left looks like it’s for an external antenna ….
reggieiscrap@reddit (OP)
In the video the power supply connects to the bottom right of the machine..
solidpro99@reddit
Many others are saying that port bottom-right is for a handset connection (to use the machine as a mobile phone)
reggieiscrap@reddit (OP)
Hopefully this helps..
IBM PC Radio 9075 power supply
https://imgur.com/gallery/LL1ydiX
Happy to clarify any queries
solidpro99@reddit
That’s great, thank you! I don’t suppose you could do a voltmeter test on each of the holes? 🙏
reggieiscrap@reddit (OP)
I'll put the task in queue...
solidpro99@reddit
Usually you can use the outer shield as a source of ground and then just test each of the pins inside? Thanks!
reggieiscrap@reddit (OP)
Hi... apologies for the delay.. finally got to this..
The power pack is powering the device on.. however.. all pin to external shield DC voltage readings are 0.
I've tried two paper clips... inserted in different pin holes.. I did this once.. and read 8.9v briefly.. I will work this further.. with pins that don't move..
Sorry it's not positive news.. some information is better than none
solidpro99@reddit
Hi - thanks for trying so far - not exactly much to go on then! You notice there is one centre PIN and then if you take the keyed ‘notch’ at the top, or 12 o’clock position, then you have a left pin, a right pin and a bottom pin. Maybe you could see if the centre is ground by continuity testing it to another ground anywhere on the PSU? Actually I’ll see what I can continuity test off my one….
reggieiscrap@reddit (OP)
Looking at the power supply pin holes.. central and 3 surrounding at 10, 2 and 6 o'clock respectively. With -ve / black multimeter probe on centre, 10 o clock = -9vdc, 6 o clock -8.73vdc, 2 o clock 0v.
reggieiscrap@reddit (OP)
So you would like me to check the voltage of every pin in reference to the centre pin is that correct?.. there is no ground on the PSU.. it is 2 pins only
reggieiscrap@reddit (OP)
👍🏻👏
solidpro99@reddit
Thank you!
exclaim_bot@reddit
You're welcome!
reggieiscrap@reddit (OP)
The part number is 92F1107