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I was bored and found a HP-27S
11-08-2020, 06:39 PM
Post: #79
RE: I was bored and found a HP-27S
(11-06-2020 08:42 PM)Massimo Gnerucci Wrote:  From a reset condition it should wake up by beeping since beeper is set on by default.
To be sure try a division by 0, this should make it beep.

If you don't hear anything (and the beeper is connected to the PCB) it should still be dormant.

Infinite thanks! it makes a sound!
I connected an external piezoelectric buzzer to the springs and short-circuited between points P1 and P2 which are the contacts of the ON button. To tell all what happened, the beep came out only by touching P2 connected to nothing else
Now you have to understand why you don't see anything on the display ... Is there any possible test to do on the display alone to see if the problem is there?
Any suggestions for fixing the PCB on the keyboard / screen contacts without twisting the hooks (which otherwise I will end up breaking in attempts)?
Can the display depend on the components mounted on the PCB? (I don't know if they are capacitors or resistors ... but they are the only parts that can be replaced). I don't think the oscillator died as a sound was emitted ...

Hardware: Hp48S - Hp50g (5x black + 1 blue) - HP39gII - Hp27s - Casio fx-CG50
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Messages In This Thread
I was bored and found a HP-27S - jebem - 06-09-2014, 10:38 PM
RE: I was bored and found a HP-27S - jebem - 06-10-2014, 09:35 AM
RE: I was bored and found a HP-27S - jebem - 06-25-2014, 06:49 PM
RE: I was bored and found a HP-27S - jebem - 06-26-2014, 01:44 PM
RE: I was bored and found a HP-27S - jebem - 06-26-2014, 01:40 PM
RE: I was bored and found a HP-27S - jebem - 06-26-2014, 03:57 PM
RE: I was bored and found a HP-27S - jebem - 06-27-2014, 01:15 PM
RE: I was bored and found a HP-27S - jebem - 06-27-2014, 08:50 PM
RE: I was bored and found a HP-27S - HP67 - 06-27-2014, 02:56 PM
RE: I was bored and found a HP-27S - HP67 - 06-27-2014, 03:28 PM
RE: I was bored and found a HP-27S - jebem - 06-27-2014, 10:18 PM
RE: I was bored and found a HP-27S - jebem - 06-27-2014, 10:58 PM
RE: I was bored and found a HP-27S - jebem - 06-28-2014, 08:02 AM
RE: I was bored and found a HP-27S - jebem - 06-27-2014, 10:46 PM
RE: I was bored and found a HP-27S - jebem - 06-28-2014, 07:55 AM
RE: I was bored and found a HP-27S - jebem - 06-27-2014, 10:56 PM
RE: I was bored and found a HP-27S - jebem - 06-27-2014, 11:05 PM
RE: I was bored and found a HP-27S - jebem - 06-28-2014, 04:44 PM
RE: I was bored and found a HP-27S - jebem - 06-28-2014, 05:37 PM
HP-27S that does not turn on - franz.b - 11-06-2020, 08:24 PM
RE: I was bored and found a HP-27S - franz.b - 11-08-2020 06:39 PM
RE: I was bored and found a HP-27S - jebem - 11-09-2020, 07:14 AM



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