HP 33E - died?

[Eddie W. Shore]

I plugged in my HP 33E and it cycled between zeros and decimal points. Is there anyway to wake up the 33E or is it of what I fear, dead?

Not an April's Fools Joke.

Eddie

[aurelio]

(04-01-2022 08:31 PM)Eddie W. Shore Wrote:  I plugged in my HP 33E and it cycled between zeros and decimal points. Is there anyway to wake up the 33E or is it of what I fear, dead?

Not an April's Fools Joke.

Eddie

Hi Eddie, did you check inside the battery compartment? it's all right? any trace of corrosion?
Is it a a soldered spice version or not? maybe a problem of bad contact between the components and the board. Anyhow I guess not still dead, but mad... if the display show something

[Eddie W. Shore]

(04-01-2022 08:54 PM)aurelio Wrote:  

(04-01-2022 08:31 PM)Eddie W. Shore Wrote:  I plugged in my HP 33E and it cycled between zeros and decimal points. Is there anyway to wake up the 33E or is it of what I fear, dead?

Not an April's Fools Joke.

Eddie

Hi Eddie, did you check inside the battery compartment? it's all right? any trace of corrosion?
Is it a a soldered spice version or not? maybe a problem of bad contact between the components and the board. Anyhow I guess not still dead, but mad... if the display show something

I think it is soldered? It has been modified to fit two AA batteries.

[Steve Simpkin]

You said you plugged it in. Don’t use the AC charger unless there are known *good* rechargeable NiCad or NiMH batteries installed and all contacts are good. The batteries in Spice and Woodstock models are used to filter and provide voltage regulation of the unregulated output of the charger. Better yet, never plug in the charger to be on the safe side. Try running it on batteries.

[Eddie W. Shore]

I put in one of the new batteries. Got the display going for a few seconds before going out. I think one of the aluminum tabs on the positive side of the batteries is missing.

I'm not an expert at electronics, at this point I am going to try to find someone who repairs HP 33Es or I am willing to give it to someone who can use it for parts.

[aurelio]

(04-01-2022 10:50 PM)Eddie W. Shore Wrote:  I think it is soldered?

Eddie I mean there are two versions of calculators in the spice series, at the beginning made with a standard assembling method, soldering the CHIPS on the PCB, then they were just placed on it (unsoldered). You can find more details and descriptions on this Jose's post and other Museum's links

Edit: typos

[Massimo Gnerucci]

(04-02-2022 01:20 PM)aurelio Wrote:  

(04-01-2022 10:50 PM)Eddie W. Shore Wrote:  I think it is soldered?

at the beginning made with a standard assembling method, soldering the CHIPS on the PCB, then they were just placed on it (unsoldered).

Wasn't it the other way round?

[Eddie W. Shore]

https://drive.google.com/file/d/1NZbo5lr...sp=sharing

Was able to take a peak, saw a backbone - so I think unsoldiered?

https://drive.google.com/file/d/1XcBiFOK...sp=sharing

Unfortunately, I think I broke it - I can't put the back case back on!

https://drive.google.com/file/d/1VehYwR8...sp=sharing

Does anyone want this for parts? Otherwise, I'm just probably going to send this for electronics disposal.

This is why I don't bother with repairs. Sorry I let you down, Dave.

[aurelio]

(04-02-2022 02:06 PM)Massimo Gnerucci Wrote:  

(04-02-2022 01:20 PM)aurelio Wrote:  at the beginning made with a standard assembling method, soldering the CHIPS on the PCB, then they were just placed on it (unsoldered).

Wasn't it the other way round?

Yes Massimo you are right, maybe I made confusion by turning the wine into water

[rprosperi]

(04-02-2022 02:43 PM)aurelio Wrote:  

(04-02-2022 02:06 PM)Massimo Gnerucci Wrote:  Wasn't it the other way round?

Yes Massimo you are right, maybe I made confusion by turning the wine into water

Well, my Nonno from Pesaro taught me that if you don't make the wine yourself, it probably tastes like water... though this is the same man who greatly annoyed my mother giving me small sips of Vermouth when I was 4 days old. When she screamed, he reportedly told her "It's OK, he's Italian too, and they were very small sips...".

And yes Massimo, the 'clamped' style came first. Weirdly unreliable behavior, but excellent keyboards.

[Massimo Gnerucci]

(04-02-2022 06:34 PM)rprosperi Wrote:  Well, my Nonno from Pesaro...

Paisà!

[GreyUser]

(04-02-2022 06:34 PM)rprosperi Wrote:  And yes Massimo, the 'clamped' style came first. Weirdly unreliable behavior, but excellent keyboards.

Perhaps from a pressure and tactical feedback viewpoint but certainly not from a reliability standpoint, the keyboards were no better than the other mechanical aspects of the original 30 series design. Engineered to a price point, nothing more.

I’m certain most collectors know the 30 Series was a rushed design. What may not be as well known was that the series was put into production before accelerated life testing was complete on the new keyboard design. If you look closely at the flexing dome sheet of an original keyboard, you’ll see conductors on the plastic dome sheet that travel through the flexing areas of the domes. Yep, they fracture and fail as expected.

So, the redesign using a soldered chip pc board and the keyboard design of the 41 wasn’t because it was cheaper, it was because the original design was flawed in every way.

I’ll agree with you that the redesign resulted in a nice keyboard. But, it still suffered from the 20 series battery charger flaw and a crappy, weak mechanical design for the battery contacts.

[Steve Simpkin]

GreyUser, thank you for that information. I suspect that around 1976-1977 HP was really feeling the pressure from all of lower cost competitors in the scientific calculator field. This probably helps explain why the 30 series was such a rush job and all of the cost saving measures HP took. I remember my High School chemistry class around 1978-1979 that a scientific calculator was required. I believe I was the only one in the class with an HP (a HP-25). Everyone else has a TI, Casio, Sharp, etc. I have to think cost (and maybe RPN) was a big factor.

Regarding the risky, low-cost charging system used in the Woodstock and Spice models. I wonder if the ICs used in Spice models were better able to withstand the high voltage applied to them when using the charger without the batteries installed. I have heard so many cases where the ACT chip was fried from this in Woodstock models. I have heard other cases where this was done to a Spice model and it survived the experience. The warning messages in the Owner’s Handbook about operating the calculator on the adapter without batteries installed also changed between the two series. The warning is much more dire in the Woodstock manual (first picture below) than in the Spice manuals (second picture). Just something I have observed.

[teenix]

(04-02-2022 02:28 PM)Eddie W. Shore Wrote:  Does anyone want this for parts? Otherwise, I'm just probably going to send this for electronics disposal.

A shame that maybe a gamble for postage cost didn't stack up. I would have been happy to take a look at it. You never know, it might have been something simple.

cheers

Tony

[Eddie W. Shore]

(04-04-2022 12:03 AM)teenix Wrote:  

(04-02-2022 02:28 PM)Eddie W. Shore Wrote:  Does anyone want this for parts? Otherwise, I'm just probably going to send this for electronics disposal.

A shame that maybe a gamble for postage cost didn't stack up. I would have been happy to take a look at it. You never know, it might have been something simple.

cheers

Tony

Tony,

I ended up offering it for parts, and ended up sending it the same day. Fingers crossed that the either the HP 33E can be resurrected or the keys and parts can be used to repair other HP 33Es.