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Further use of HP41CV with defect ports 2&4 ? or..?

PostPosted: Wed Sep 01, 2021 4:17 pm
by floppy_stuttgart
Hello,
an HP41CV I have has ports 2 and 4 defects. Now I have to decide what to do. Following options come to my mind.. (no hurry; I have a full function HP41CX and a crippled 41CV which dont accept Nov64d but all ports working).
a) further use as it is with Nov64d in Port 1 and HP-IL in Ports 3 (no X-memory, no further modules can be added)
b) repair (I already asked to a shop how much; I expect around 100eur) for ports 2 and 4
c) a full rework with a HL cuircuitry (and port 2 and 4 exchange)
d) keep it as desk calculator without any module (or for youth starting programming)
Any opinion/comment is welcome.
People with experience with port repair or rework to CL are welcome.

Re: Further use of HP41CV with defect ports 2&4 ? or..?

PostPosted: Thu Sep 02, 2021 12:01 pm
by BillBee
Hi Floppy,

I have had this happen and replacing the ribbon strip fixed it - but I knew I had corrosion issues. The procedure is pretty easy (you can buy just the ribbon and use it to replace the one on your block) or a completed replacement unit is available. The Calculator Store (in Spain) carries the parts and I have made multiple purchases from them with no problems. One thing I do recommend is prior to ordering, open the unit up and see if the upper screw bosses have cracked. Its pretty common and not a tough repair. The screw bosses if not providing proper pressure can cause screwy behavior. Just a couple of things to consider.

Regards!
Bill

Re: Further use of HP41CV with defect ports 2&4 ? or..?

PostPosted: Thu Sep 02, 2021 3:43 pm
by Garth
http://www.clonix41.org/Maintenance/IO_ ... _Block.htm
There's a video showing how to install the replacement at http://youtu.be/jUTAZSEn-H8 .

Re: Further use of HP41CV with defect ports 2&4 ? or..?

PostPosted: Fri Sep 03, 2021 8:46 am
by floppy_stuttgart
BillBee wrote:Hi Floppy,

I have had this happen and replacing the ribbon strip fixed it - but I knew I had corrosion issues. The procedure is pretty easy (you can buy just the ribbon and use it to replace the one on your block) or a completed replacement unit is available. The Calculator Store (in Spain) carries the parts and I have made multiple purchases from them with no problems. One thing I do recommend is prior to ordering, open the unit up and see if the upper screw bosses have cracked. Its pretty common and not a tough repair. The screw bosses if not providing proper pressure can cause screwy behavior. Just a couple of things to consider.

Regards!
Bill

I see. Preferably I will order later a full mounted unit https://www.thecalculatorstore.com/epag ... ledFlat%22
What do you mean with "screw bosses" ?

And thanks Garth for the video. But my builder fingers would probably not made it.. ;-)

Re: Further use of HP41CV with defect ports 2&4 ? or..?

PostPosted: Fri Sep 03, 2021 10:29 am
by BillBee
floppy_stuttgart wrote:
BillBee wrote:Hi Floppy,

I have had this happen and replacing the ribbon strip fixed it - but I knew I had corrosion issues. The procedure is pretty easy (you can buy just the ribbon and use it to replace the one on your block) or a completed replacement unit is available. The Calculator Store (in Spain) carries the parts and I have made multiple purchases from them with no problems. One thing I do recommend is prior to ordering, open the unit up and see if the upper screw bosses have cracked. Its pretty common and not a tough repair. The screw bosses if not providing proper pressure can cause screwy behavior. Just a couple of things to consider.

Regards!
Bill

I see. Preferably I will order later a full mounted unit https://www.thecalculatorstore.com/epag ... ledFlat%22
What do you mean with "screw bosses" ?

And thanks Garth for the video. But my builder fingers would probably not made it.. ;-)


Hi Floppy,

Its common for the 41s to have a "broken back" where under the supporting plastic under the upper feet (where the screws are accessed) break. As you may imagine, it stops the case back from creating the pressure on the IO block and the ribbon cable will have connection issue with the circuit board. It is a relatively easy repair if that is the case.

Keep in mind it is all speculation on my part as your CV is functional beyond the two port issues. You will find out the condition of all when the disassembly is performed.

Have a good one!
Bill

Re: Further use of HP41CV with defect ports 2&4 ? or..?

PostPosted: Thu Oct 14, 2021 10:15 am
by floppy_stuttgart
Topic closed.
The HP41CV went lost during a sending via DHL to a person for repairing. The worst thing (money will be paid back by DHL because it had an insurance; at least this is what I expect), the accumulator pack is gone and thats not easy to find a new one.