HP-48SX (attempted) repair by Ben Heck

[ijabbott]

He is not impressed by its ease of repairability!

[rprosperi]

This guy is new to me.

Does he actually ever repair and reassemble items?

[Eric Rechlin]

I'm pretty sure he accidentally downloaded the instructions that explained how *not* to open an HP 48 instead of how to open one.

I was under the impression the best way to do it was to use a heat gun to soften the adhesive behind the faceplate, then carefully peel that back, and then drill out the rivets from above.

Still, it was interesting to see his impressions of just how advanced the 48SX was for its time. The 48G series just doesn't look as cool inside, though it does look much more modern.

[Geoff Quickfall]

Yep, it was a cringeworthy how not to do it!!!!!!!!!


Eric is corrrect, the best way is in through the front after you shave the two heat stakes in the battery conpartment”

Opening the HP 42S which is the same way as opening the stretch pioneers.

And here:

Article in HP solve

[BillBee]

That was a ham-handed teardown not a repair attempt IMO. Even muted I couldn't watch that.

I've opened a few 48Gs by just popping the rivets - they all went back together with a nice "snap". Also, I have found shimming does not reliably work and the strip should be replaced if tightening the tabs a bit doesn't work.

Biggest issue was being selective in use of force for the lower rivets. Too much force and you will get a nice banana shaped keyboard.

But YMMV.

Bill

[ijabbott]

(09-15-2021 02:38 AM)rprosperi Wrote:  This guy is new to me.

Does he actually ever repair and reassemble items?

He's more of a maker than a fixer, tbh, often making things cobbled together from other things. He used to have a show (on Youtube) sponsored by element14, but now just does his own stuff. Still, his impressions of other youtubers, and his random, improvised songs are kind of fun to listen to.

[Ren]

(09-15-2021 02:38 AM)rprosperi Wrote:  This guy is new to me.

Does he actually ever repair and reassemble items?

Were you just being facetious?
I've known of him for several years, though I don't "follow" him.

His videos have appeared a number of times on Hackaday.com

https://hackaday.com/blog/?s=Ben+Heck

[Liamtoh Resu]

makers and fixers and labels, oh my!

Not everyone knows about the difficulty of obtaining older HP calculators.

I was virtually aghast watching the hp49sx being torn apart.

I consider my self to have purchased an HP50g in 2016 and an HP 38g recently.

Of course some parts for popular microprocessor projects have sometimes become
hard to purchase.

I too enjoyed the cheezy Bill Murray type lounge singing.

cheers.

[rprosperi]

(09-15-2021 08:12 PM)Ren Wrote:  Were you just being facetious?
I've known of him for several years, though I don't "follow" him.

His videos have appeared a number of times on Hackaday.com

https://hackaday.com/blog/?s=Ben+Heck

No, it was a serious question. His style, obvious experience (and singing) are all fine and I would not mind watching his videos, I just didn't know about his success/failure rate. Though a lot can be learned from watching even repair failures, it would be encouraging to know some items do in fact get repaired.

Learning he's more of a builder changes one's view of his repair skills, and he surely is not the first (nor the last) experienced tech to get flummoxed trying to open an HP-48. His questions, "how the heck did they open these to repair them?", "why did they use twist tabs?", etc. reveals the assumption we've all made that they were in fact to be serviced, but clearly not the case.

So I may check him out again in the future.

[ijabbott]

(09-15-2021 09:46 PM)rprosperi Wrote:  

(09-15-2021 08:12 PM)Ren Wrote:  Were you just being facetious?
I've known of him for several years, though I don't "follow" him.

His videos have appeared a number of times on Hackaday.com

https://hackaday.com/blog/?s=Ben+Heck

No, it was a serious question. His style, obvious experience (and singing) are all fine and I would not mind watching his videos, I just didn't know about his success/failure rate. Though a lot can be learned from watching even repair failures, it would be encouraging to know some items do in fact get repaired.

Here's one where he actually fixes something, and more singing!

https://youtu.be/0PIRSccfreY

[aurelio]

Uncredible.....

I've not understood, really, if the calculator he opened was actually faulty or not....

[aurelio]

Geoff, I missed this your old post.
How did you succed in removing the overlay so perfectly?
I removed the overlay on 32sìì time ago, but the result was not so clean.
maybe they used too much cement in assemblying it

[Geoff Quickfall]

The big thing is while heating to remove the overlay. Do not bend back while pulling more then 30 degrees to avoid creasing the overlay.

Remove the glue, I used industrial lemon oil label remover or something commercial like goo-gone.

Remove it from both the calc and the overlay.

Place the overlay now clean between two sheets of clear vinyl. Something similar in thickness to an ID vinyl holder.

On a perfectly flat surface with the overlay sandwiched as described rub the overlay/vinyl with a large smooth bowled spoon. Initially rub the top surface (silk screened) of the overlay/vinyl then flip over and repeat on the reverse side of the overlay/vinyl sandwich. This will induced a slight convex shape to the overlay allowing the corners to lay first and causing a flat attachment throughout.

I use double sided epoxy tape (same as used on iPhone gorilla glass to case attachment.

Cheers, Geoff


This also works on the metal labels found on the classics and the HP 67 Woodstock. These can be removed with the heat gun / hair dryer, de-glued and flattened in the same method.

[ijabbott]

If only he had a copy of "The Book"!

[Massimo Gnerucci]

(09-18-2021 08:32 AM)ijabbott Wrote:  If only he had a copy of "The Book"!

Oh Ian, once I refrained from teasing Geoff...

[BruceH]

(09-18-2021 08:32 AM)ijabbott Wrote:  If only he had a copy of "The Book"!

Better still, two copies and he could press the overlay flat between them! :-)

[rprosperi]

(09-18-2021 12:45 PM)BruceH Wrote:  

(09-18-2021 08:32 AM)ijabbott Wrote:  If only he had a copy of "The Book"!

Better still, two copies and he could press the overlay flat between them! :-)

Thanks Bruce, you made my day... lol.

And it's still early here, so a good thing...

[Geoff Quickfall]

Oh nooooooooooo!

[aurelio]

(09-17-2021 09:38 PM)Geoff Quickfall Wrote:  The big thing is while heating to remove the overlay. Do not bend back while pulling more then 30 degrees to avoid creasing the overlay.

Remove the glue, I used industrial lemon oil label remover or something commercial like goo-gone.

Remove it from both the calc and the overlay.

Place the overlay now clean between two sheets of clear vinyl. Something similar in thickness to an ID vinyl holder.

On a perfectly flat surface with the overlay sandwiched as described rub the overlay/vinyl with a large smooth bowled spoon. Initially rub the top surface (silk screened) of the overlay/vinyl then flip over and repeat on the reverse side of the overlay/vinyl sandwich. This will induced a slight convex shape to the overlay allowing the corners to lay first and causing a flat attachment throughout.

I use double sided epoxy tape (same as used on iPhone gorilla glass to case attachment.

Cheers, Geoff


This also works on the metal labels found on the classics and the HP 67 Woodstock. These can be removed with the heat gun / hair dryer, de-glued and flattened in the same method.

what a technique, Geoff

[EugeneNine]

IPA will soften the adhesive to where it doesn't even bend, was no need for him to ruin it.