Hp 42s Calculator Repair & Upgrade - Keyboard repair & 32kb Memory Ram Upgrade

[@katenogarede8391]

Thank you so much for posting this! I was able to repair my 32SII and it works great now. I was nervous about breaking the rivets, but your instructions were straight forward and easy to follow.

[@pchoudhu]

Thank you for this, watched your video several times before opening a 42s to add some foam. Works fine now. Much appreciated

[@JSeb68]

I'm glad to report that I was able to unbrick my long dead HP-42S thanks to your video! Self-test still gives ma a keyboard error, but I'll figure that out later. Thank you!

[@TheNimsloGuy]

That is so awesome to hear! These are incredible machines and the RPN language is so intuitive it's amazing we ever switch over to anything else. If you're still getting a keyboard error you might need to reinforce the foam behind the contact traces.

[@pchoudhu]

I thought I was getting keyboard errors but make sure when you get to the KBD prompt to press each of the keys starting from top left to bottom right once, then you should get the OK if everything is fine

[@Skans-Gustav]

This was an excellent video. I managed to open and close my 32S and get it to work properly. One gadget had actually dropped loose from the board and unbelievably I could just guess where it had been located and simply glued it back in place with epoxi. Then I also removed and replaced the foam strip and it’s back to normal again. Had to epoxi the lower edge later to hold it down properly and fitted two screws in the top rivet holes. Hope I never have to reopen it again. Thanks again, good tip clipping two or three sides of lower rivets. A bit nerve-racking to twist those 6 clips but it apparently worked. I can also recommend the free app Free42 which is a copy of the 42S to use on an iPhone.

[@alanncsu3243]

You need to re-label yours to 32S-F... Frankenstein model. :D

[@johnl2727]

This is two years old with a lot of great info BUT ... I wish you would repeat it with more attention to keeping the calculator in the center of the screen. Also, there must be a jumper you cut for the calculator to know whether the RAM is 8K or 32K. Please show it closer and slower so we can see it. Thanks

[@carstenrasmussen1159]

I know that the video is a little old but I have a hp42s which I used for my masters one side of the keyboard stops working. I would like to get it repaired but I don't do it myself because I don't want to destroy it.

[@fragglet]

14:10 - you could also put some kapton tape over the CPU to protect it and its plastic mounts from the soldering iron. Very good video though

[@frankfirst6863]

Excellent tutorial. Thank you very much 😎😎

[@alanncsu3243]

My display has bad pixels, wondering what my options are - I could buy a scratched model with a working display for a repair... unless you already have the part and can do the fix for me? Just thought to ask...

[@WMSFLL]

apparently I need to do the foam thing to my 22S calculator. the right side functions no longer work unless I press down where the contact points are. What kind of adhesive foam are you using? Approx. thickness?

[@benmkongo4927]

Thank you very much for your explanations. I have this kind of calculator. After 30 years of use the screen has deterioted. Some pixels are not visible. Can the screen be restored as well?

[@TheNimsloGuy]

you can replace the screen from a 21s, 22s or 27s I believe if you have a burn or damage. if you’re just missing pixels then it’s likely you just need to remove the board and clean the connector on the zebra strip as either dust or other detriments have gotten under it. q tip with rubbing alcohol works best and make sure no fuzzies are left behind

[@franbertrand7213]

do you have any old calculator circuit boards with chips that you do not have no use any more

[@TheNimsloGuy]

Sorry, Not really. Most of what i carry and use is for repairs and upgrades. What were you looking for in particular?

[@eliasamaral5903]

Quero e preciso concertar duas calculadoras HP42s é possivel

[@michaelkang215]

Thank you for saving my 42S!!!! It has sentimental value that no money can buy. There are 2 vertical lines that don't show no matter what I do. I am using Bausch & Lomb BioTrue multi purpose solution. What is the solution that you are using? One last question. How many times can the locking tabs to locked and unlocked before they break? I ask because I have done it a fair number of times already. Anyway, thank you for the video. It helped me so much.

[@TheNimsloGuy]

If you can't get them to show up it's most likely either dirt/liquid got under the Zebra ribbon and that will need to come up and be cleaned on the conductive glass side of the display. Though i've see a few times that pixels/columns may just be dead. If that's the case it's either due to a bad trace on the board or a fault in the lcd. the hp 27s and i beleive the 32sii, and 22s? not sure on the last one should all use the same lcd screen that could be used as a donor.

[@michaelkang215]

@@TheNimsloGuy Thank you for your input. Can the age of the machine effect the display contrast? The display’s contrast is pretty weak no matter how much I adjust using “+” and “-“. Any thoughts?

[@TheNimsloGuy]

@@michaelkang215 different displays have different contrast level, but age can definitely effect it as well. Do you have the display with the plastic cover over it or without?

[@michaelkang215]

@@TheNimsloGuy I have a standard 42s. No plastic cover. I was so heart broken when it didn’t work. But thanks to you, it shows life. :) Question. How many times can I untwist to unlock and twist again to lock? I want to see if I can make the two missing vertical lines work but I also don’t want to twist off the tabs.

[@TheNimsloGuy]

@@michaelkang215 It's usually about 3-4 times. Depending on how much they were twisted before. But after that the probably of them breaking off gets pretty high.

[@RixtronixLAB]

Nice video, thanks for sharing with us, well done :)

[@charliehoey7601]

super helpful, thank you!

[@guillermomorenomedina7061]

hola im gusto que se debe estudiar para aprender a arreglar las calculadoras

[@michaelhogan738]

Hi Nimslo Guy. I was also impressed with the beauty of the circuit board when I opened this thing up! My original idea was to see if I could incorporate LED backlighting for the LCD screen. What do you think? Would that be possible? Also, do you know what that unpopulated landing for another chip was/is for? Thanks for a great video!

[@claudcameron4991]

Do you do repairs? This is likely above my skill level.

[@llau8482]

Some of your video was not in focus at around 6:00.

[@keyboard_g]

Lets not forget half of the video was performed off screen. 😂

[@rudiger86]

great work play boy