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plivesey · 06-03-2019, 06:03 PM

So I was flashing my WP34S today as it was running a very old version of the firmware and something's gone wrong.

It appears to be very dead and refuses to turn on or accept a new flashing. Any suggestions? I'm using the serial programming cable and it was originally an HP 30b.

Any help or advice would be greatly appreciated.

plivesey · (This post was last modified: 06-03-2019 11:46 PM by plivesey.)

Further information.

The batteries in it were dead, but not leaking. This was a surprise as they should have been good, the calculator having not been used much since they were put in.

Anyway, I replaced them with a brand new new pair. I flashed it once with an old firmware (by mistake) and it worked. Repeated the process with the latest firmware and that's when it died.

Having checked the new batteries now, they're both at ~2.7V

Took the back off to see if anything was obviously amiss and a few of the tracks leading off from the left hand battery terminal where it joins the PCB appear a little corroded. Again, no signs of battery leakage though.

I'm thinking it's not coming back from this and so it's off to the internet to get gouged for a new HP 30b.

ijabbott · (This post was last modified: 06-03-2019 11:20 PM by ijabbott.)

The batteries do get drained quite heavily while it is in the "dead" state. The calculator should be recoverable, but you will probably need more fresh batteries or something beefier to try flashing it again. (I use a bench power supply.)

See this archived thread for starters: HP 30b bricked when repurposing.

burkhard · (This post was last modified: 06-04-2019 05:36 PM by burkhard.)

An open-circuit voltage of 2.7V (on the "new" batteries) is pretty marginal I think.

If the calculator had already been flashed, you could probably run like that (but not long before the Low Battery annunciator comes on), but the flashing operation itself is a bit power-intensive and I suspect the voltage will dip further (too far?) when that load is applied.

I think I'd try again with some new(er) batteries and perhaps a bench supply like the prior commenter recommends. I have doubts that you have killed it.

plivesey · 06-05-2019, 05:30 PM

It's been a couple of days and I've finally got it working again, but it took a bit of hand waving.

In the end I bought a PCIe serial port card so I didn't have to use my USB to serial port adapter, I threw in some new batteries (I'd bought a six pack which was fortunate), fired up a fresh copy of mysamba and it flashed first time. Very happy with the result.

The graduate I'm mentoring saw me using the WP34S iPad app and asked what the hell it was, so next week I can show him the real thing.

**rprosperi** · 06-05-2019, 05:36 PM

Congrats on rescuing your 34S. They seem to be truly hard to break permanently.

Also, nice that you're showing off some vintage RPN technology (even if the 34S isn't itself actually vintage) to your student; let him/her know the 'old ways' are still relevant, and maybe even better than most modern tools.

plivesey · 06-05-2019, 05:57 PM

My HP16C may get an outing too. He's a computer science graduate and my plan is to thoroughly corrupt him.

grsbanks · 06-05-2019, 09:11 PM

(06-05-2019 05:57 PM)plivesey Wrote: My HP16C may get an outing too. He's a computer science graduate and my plan is to thoroughly corrupt him.

A 16C is a good way to go about that Smile