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Bricked hp30b wp34s
05-18-2014, 04:10 PM (This post was last modified: 05-18-2014 04:47 PM by jebem.)
Post: #2
RE: Bricked hp30b wp34s
From your description, I don't think you had the opportunity to flash it.
The message from mySamba is just telling that it cannot talk to the calculator.

However, if you did the ERASE operation, it is normal that the calculator looks "dead" when you power it on.

I would check and eliminate possible causes:

1. Test your usb to serial adapter for good operation:
- Interconnect the TxD and RxD serial pins of the adapter with a 1Kohm resistor to create a loopback connection;
- Open Windows device manager and check for COMx ports; leave it running;
- Plug the usb to serial converter to the Windows PC;
- Windows should recognize the new device and load the correct driver; you will be able to see an additional COMx port in Device manager; take note of that port nb;
- Get a copy of Windows XP Hyperterminal program and run it (well, if you are running Windows XP the tool is there already!); create a new session, and start typing on the keyboad: if your usb to serial adapter is working fine, you should be able to see the typed keys as echoed characters inside Hyperterminal;

2. Test your HP-30B

- Unplug/unsolder any wires from the back;
- If you do not have CR2032 3V cells at hand, get two AAA or AA batteries, connect them in series to have 3Volt (I use a battery holder) and use clip wires to power the calculator: in the cell's holder, the central cell contact is the Negative (-V) and the outer lateral contact is the Positive (+V); both CR2032 3V cells are connected in parallel in the cell's holder;
- power on the calculator to see if it works; if yes, the calculator was not Erased yet; if not, you need to remember if you did the Erase sequence!
- assuming that you did the Erase, take a digital multimeter, select current readings in mA (200mA full scale is enough) and insert it between one of the AA/AAA batteries contacts and the clip wire, to measure the consumed current; power on the calculator, and you should see a number there, like 2 to 20 mA; this indicates that the calculator is probably OK, it is just waiting to be flashed;

3. If points (1) and (2) passed OK, then it is time to try again!

Just to remember, you need to use 3 wires from the serial adapter to the calculator:
- GND (Ground);
- Txd from the serial adapter connects to the RxD in the calculator;
- RxD from the serial adapter connects to the Txd in the calculator;
- I would use two 1Kohm current limiting resistors, one in the TxD and anotther in the Rxd wire.
- I would NOT use the 3.3Volt from the usb to serial adapter to supply power to the calculator: it does NOTsupply enough current! Use the above 2 x 1.5Volt AA/AAA batteries in serial in a battery holder, or the CR2032 cells inserted. That is probably the main reason why the flash operation is not working.

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Messages In This Thread
Bricked hp30b wp34s - thedanielm - 05-18-2014, 03:09 PM
RE: Bricked hp30b wp34s - jebem - 05-18-2014 04:10 PM
RE: Bricked hp30b wp34s - thedanielm - 05-18-2014, 04:50 PM
RE: Bricked hp30b wp34s - thedanielm - 05-18-2014, 11:15 PM
RE: Bricked hp30b wp34s - thedanielm - 05-19-2014, 01:02 AM
RE: Bricked hp30b wp34s - thedanielm - 05-31-2014, 06:07 PM

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