[NTLK] Notephone and OMP/MP100 issues

[Paul Curtis]

Frank,

I can honestly say I haven’t run into any of these issues!

Mostly because I don’t use it - hehehehehehehehehehe. 

It’s beautiful just to light up my little green friend and pretend to call people!

Sent from my iPhone

> On Nov 24, 2020, at 6:20 PM, NewtonTalk <newtontalk at pda-soft.de> wrote:
> 
> 
>> 
>> About the Notephones and their motherboard...
>> What do you mean by "a certain degree temperature-related"?
>> Do you mean that certain components are too sensitive and if
>> they heat up too much they no longer work?
> 
> Having no technical documentation whatsoever, that's hard to say.
> 
> Fact is that the problem lies on the base station mainboard. If you remove
> it, put it in the fridge, leave it there for an hour, take it out again,
> connect it to the handset and to a phone line FAST, you'll normally get a
> dial tone. "Normally" because some Notephones won't even work when the
> mainboard is cold, but the majority will. If the mainboard was connected to
> the keyboard, you would now be able to make a phone call. When the mainboard
> warms up, the problem resurfaces. This normally takes less than a minute.
> When you press and release the hook switch on the mainboard, you won't get a
> new dial tone. You must put the mainboard back in the fridge for some time
> first. So the problem, whatever said problem is, is DEFINITELY
> temperature-related insofar that it occurs way less often when the mainboard
> is cold. And it's definitely on the mainboard because apart from the handset
> and the phone cable that's all you're using. And in all likeliness it is
> caused because the phone lines a and b aren't getting sufficiently
> high-ohmic when the hook switch is down, since this is what tells the toll
> office that you've hung up.
> 
> I do not think that any components heat up too much. None of them seems
> overly hot to the touch while the problem is there. Spraying components with
> coolant spray doesn't help. It seems that after the problem shows up, the
> whole mainboard needs a longer rest in the fridge to make it work again for
> the next couple of moments. 
> 
> I cannot make any educated guess here. Normally you can find
> temperature-related problems comparatively easy with a hairdryer and a can
> of coolant spray. But all attempts I made so far failed miserably. On one
> board I replaced all electrolytic capacitors, but this didn't fix things,
> either. But I think you can safely assume that the problem lies somewhere
> between the cradle switch (which, as I said, is perfectly OK) and the phone
> lines a and b. After all, it's those phone lines that tell the toll office
> that you've hung up, and this message obviously doesn't come. Or it doesn't
> come clear enough or long enough. It might even be possible that the
> Notephone isn't defective at all, but simply can't work with the voltage
> nowadays supplied to the phone lines a and b. Normally this used to be
> around 60 Volt, but phones were able to work OK with much less than that
> because there'd be a voltage loss if your phone was located far away from
> the toll office. A Fritzbox, for example, will only provide around 35 Volt
> to their analog phone sockets.
> 
> If I ever find the time to tackle this again, I'll probably educate myself
> first what must happen on the phone line to signalize that you've hung up,
> and then start measuring backwards. It'll be difficult, though, because
> there are some weird integrated circuits along this path.
> 
> Cheers
> 
> Frank
> 
> -- Newton software and hardware at http://www.pda-soft.de
> 
> 
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