Dstines Mark X Tricorder repair/battery replacement

[ReelClones]

I have a Starfleet R&D/ DStines Medical Tricorder which no longer holds a charge. The back of the Tricorder was glued in so had to be pried open in order to reach the batteries!

So far so good, but what greeted me inside is a little beyond my electronics level! There are two rechargeable batteries which are normal, but it also has two metal rectangles that are wired in. I see no markings on them. Are they a type of battery? Anyone able to help me out with identifying a suitable replacement of all this so I can get the Mark X up and running again?!

 

[smithjohnj]

They look like they might be low profile aluminum electrolytic capacitors.

​

 

[AnubisGuard]

Someone else had this issue some time back and IIRC gmprops was able to help him out. Perhaps he could chime in here.

 

[gmprops]

My first thought was that it was a stripped Type J battery; however, they are not rechargeable. But looking further they have to be 4 rechargeable cells in series. The 2 AA-type would only give you 2.4V total, not enough to power the electronics. But Rayovac MM724 rechargeable batteries are NiMH based. So the two middle cells must also be NiMH. Very common during the time when DStines produced these tricorders. He could not have used 4 of the AA batteries since it would cause the back panel to bulge when closed. The existing two AA batteries can be pushed to the left and right of the circuit board; then another type of NiMH battery was used like a 9V. However, the battery would still have been too thick so they removed the outer metal jacket of the battery to make it thinner. In the end the whole thing is a mess and would eventually fail.

I would replace the entire power system with a regulated 3.7V 800mAh LiPo battery. It takes up very little room and would power all of the circuitry for several more years. It is also easy to replace when it eventually fails in 8-10 years. I did this with another DStines battery system about 3 years ago and it is still going strong today.

 

[gmprops]

One other note: After looking at several DStines tricorders I have found that no two battery systems are the same. He used what worked. While the tricorders work quite well, the battery tech of the time guaranteed eventual failure. We have come a long way since then.

 

[ReelClones]

My first thought was that it was a stripped Type J battery; however, they are not rechargeable. But looking further they have to be 4 rechargeable cells in series. The 2 AA-type would only give you 2.4V total, not enough to power the electronics. But Rayovac MM724 rechargeable batteries are NiMH based. So the two middle cells must also be NiMH. Very common during the time when DStines produced these tricorders. He could not have used 4 of the AA batteries since it would cause the back panel to bulge when closed. The existing two AA batteries can be pushed to the left and right of the circuit board; then another type of NiMH battery was used like a 9V. However, the battery would still have been too thick so they removed the outer metal jacket of the battery to make it thinner. In the end the whole thing is a mess and would eventually fail.

I would replace the entire power system with a regulated 3.7V 800mAh LiPo battery. It takes up very little room and would power all of the circuitry for several more years. It is also easy to replace when it eventually fails in 8-10 years. I did this with another DStines battery system about 3 years ago and it is still going strong today.

Thanks for the info gmprops , would something like this work? :

https://www.amazon.co.uk/EEMB-Battery-Lithium-Rechargeable-connector/dp/B0B5LF57SL

The Tricorder had a charging port, which I presume is no longer suitable, so how would I go about wiring the new battery to be rechargeable within the tricorder itself? There's no charging plug on the battery so would I need some kind of charging board in there?

 

[gmprops]

Thanks for the info gmprops , would something like this work? :

https://www.amazon.co.uk/EEMB-Battery-Lithium-Rechargeable-connector/dp/B0B5LF57SL

The Tricorder had a charging port, which I presume is no longer suitable, so how would I go about wiring the new battery to be rechargeable within the tricorder itself? There's no charging plug on the battery so would I need some kind of charging board in there?

Yes, that would work. For the circuitry that DStines used at that time the current was more important than the total voltage. You would need to verify that the LiPo battery has a built in voltage charge protection circuit (most do these days). Not sure what the charging port is on this one, but I always use a barrel connector charging port to prevent accidental shorting of the positive and negative leads.

 

[ReelClones]

Yes, that would work. For the circuitry that DStines used at that time the current was more important than the total voltage. You would need to verify that the LiPo battery has a built in voltage charge protection circuit (most do these days). Not sure what the charging port is on this one, but I always use a barrel connector charging port to prevent accidental shorting of the positive and negative leads.

It's some sort of jack plug. Do you think it needs to be changed?

 

[ReelClones]

Bit of an update on the repair. I removed the battery as well as a lump of sticky goo that was either degraded glue or battery leakage I really am uncertain. It’s like play-doh but stickier! Snipped and labelled the wires into the Tri, and removed the charging jack so I could disconnect the wiring from it.

I'm not sure why the builders thought gluing the back down was a good idea, but it's ruined the paint on my Tricorder! Why they didn't use screen accurate screws is beyond me! Where the back had to be prised open, even using plastic tools made for phones the glue coming away took paint with it and cracked and chipped the finish all around the opening. It's unlikely that I'll find an exact paint match over here in the UK so I may have to try repainting to the panel lines as it were in the closest match I can find, or carefully masking all the graphics and scanner bars and giving the whole thing a "blow over". I'll cross that bridge when I come to it!

I may try rewiring this into the new setup as well as fitting this original NI-MH charger jack plug to a JST male cable so it fits my PI USB battery charger.

I ordered too large a battery by mistake but it will do for testing purposes. Would have been fine if this was a science tricorder!

New wiring setup temporarily held with wire nuts for a test run. Electronics are not my forte hence my labelling everything! But does it work?!

Ok we’re back in business, Mark X you have been silent for too long! I'll solder and finalise the wiring once I have a smaller battery on hand. I've now got to think about how to fit the cover back on to allow future maintenance. The cover panel is a little thin for magnets so I may go with these countersunk m2 screws and threaded inserts I have.

They'll be more screen accurate plus allow me to easily open the thing later! As I have to repaint all/part of the Tricorder anyway, drilling holes in it may be the best option! Still weighing the pros and cons - I've marked it out ready to drill but I haven't gone through with it yet!

 

[masterjedi322]

Glad you got her up and running again!

Sean