PCB wire connection advice needed... (Mk15.x)

hoppyinca · 19th August 2007, 04:56

I apologize for the poor pic quality...

I actually have two issues... let me start from the beginning; I have an operating version of this board for comparison. This is a board for a digital display secondary for a Mk15.x (I think Mk15.5 | Mk16). the wires on the left go to the selector switch and the display. The wires on the right are for the cable from the O2 cells. I am attempting to repair this as a back up, but...

there appears to be a section of the circuit which has been scrapped off (see blue circle). On the operating unit there is no break, the circuit connects form the wire attachment to the big-o-clump of solder, as it is the wire connects to nothing in the circuit!... incase you haven't noticed I do not normally repair PCBs...

the second issue is that I only have one housing, and no good bendix connections. I would really like the internals to be easily swapped out. So I plan to swagelok the cable to the bulkhead making a watertight seal, but then I would have to solder in the event I need to swap. I am hoping there is some easy way to modify the board so that the wires can easily and repeatedly be disconnected without soldering... some kind of terminal block, but it has to be pretty low profile...

here's the pic;
digMk15brd_initialState_descrip.jpg

any advice would be EXREMELY appreciated... please ask questions if you want to help, but find that I have not described the issue clearly...

hoppyinca

**Dave Sutton** · 19th August 2007, 10:52

Hate to say it... you're going to build-in a problem with any sort of connector in there.

If the board works, it'll work forever.... and if it breaks, desoldering it is not a big deal. Soldered connections *never fail*. If it were me? I'd solder it. With that said, I solder in sensors on many rigs too... (not the Mark-15, but....). It's not a big deal. My bet is that any problems you would have with the board would be a *result* of having corrosion start in the connector you propose to use.

Swagelok connector to bring the cable thru the bulkhead is fine. Make sure the wire is the right stuff or it'll collapse. Use the nylon ferrules in a stainless steel Swagelok fitting.

Have your weight, just need to get back home to send it. It's holding down my McMaster-Carr catalog on the bench.

Dave

hoppyinca · 19th August 2007, 15:43

Quote: (Originally Posted by Dave Sutton)

... you're going to build-in a problem with any sort of connector... I solder in sensors on many rigs too...

Swagelok connector... fine. Make sure the wire is the right stuff... Use the nylon ferrules...

Have your weight, just need to get back home to send it. It's holding down my McMaster-Carr catalog on the bench.

Dave

my thinking was the connector would make secondary change out easy/ fast... thinking pre-dive checks on boat, something happened, and needs to be swapped...

The cable is the same used by original kit; bendix to the center section, no connection on meter end. thanks for the heads up on the nylon ferrules, i was going to use the standard SS ferrules.

thank you thank you... for the weight, what's going to hold the catalog down now?

hoppyinca

**Dave Sutton** · 19th August 2007, 15:46

Quote: (Originally Posted by hoppyinca)

my thinking was the connector would make secondary change out easy/ fast... thinking pre-dive checks

Then you need a second *complete secondary assembly*, not replacement guts for one secondary. Trust me here.... chances of a working system failing approach zero, and if it fails it's failed because it's flooded... changing the guts is not the answer. The original secondary display has a Bendix at the actual primary. You are going to hard wire that, so that's not an option. But: Secondaries normally connect to the center section with a Bendix too...... are you retaining this? If so, unscrew the thing there and change out an entire secondary if you are worried (and I would not be), which means you carry a complete unit including cord. If you are planning on not having a Bendix in the center section..... use a Fisher connector. Don't hard wire the cable into the center section and then think to remedy faults at the display side of the system.

Dave

hoppyinca · 19th August 2007, 16:02

Quote: (Originally Posted by Dave Sutton)

Then you need a second *complete secondary assembly*, not replacement guts for one secondary. Trust me here...

if it fails it's failed because it's flooded... changing the guts is not the answer.

Secones connect to the center section with a Bendix...... if you are worried (and I would not be), carry a complete unit including cord. If yor are planning in not having a Bendix in the center section...

Dave

parts parts parts... I can source a housing, SMI still has some, I have 2 "buldhead plates", but that's it... know of anyone willing to get rid of the "caps"... parts parts parts... this was my initial goal, 'PnP' secondaries so to speak...

was thinking more along the lines of the meter (battery not required) failing as the fault, not so much a flood, but I see your point...

I would love to have bendix everywhere, but damn those things are EXPENSIVE!!!!! the one buldhead bendix I have has been SSSOOOO molested that is it useless. all but the center #6 pin are missing from the internal side, and someone had tried to 'dig' out more pin after breakig them off, so very sad...

hoppyinca

**Dave Sutton** · 19th August 2007, 16:31

Quote: (Originally Posted by hoppyinca)

parts parts parts...

If I were giving advice? Call up Colin, order a Colkan secondary, and move on.......

If I were poor? Call up Carl, order a SARTEK secondary, and move on.......

if I were *really* poor? Call up Mark Monroe and order a PP02.com Mark-15 secondary board and build one "in a tube". Shit, build two and you'll save enough to be able to afford all the Lumberg connectors you can use on each end of both.

If I lived near me? I'd sneak into my garage and steal one of the analog secondaries that's gathering dust because I replaced them with Colkan's.... (don't do that though or my Dachshund will wake up my Doberman and then you'll be in for a face-licking).

All the rest is just a chase that's going to end up unreliable, and just as expensive in the long run.

Dave

iain-hsm · 19th August 2007, 16:52

hoppyinca.

Ive enclosed a copy of the secondary parts list and a parts drawing from the manual. As the parts come up military surplus, chasing with these part numbers can only help.
edit. (Just noticed you may have to enlarge the pdf file to 400% to read full screen.)

hoppyinca · 19th August 2007, 17:00

Quote: (Originally Posted by iain-hsm)

...copy of the secondary parts list and a parts drawing from the manual....

thank you thank you...

hoppyinca

hoppyinca · 19th August 2007, 17:02

Quote: (Originally Posted by Dave Sutton)

...sneak into my garage and steal one ...

sorry, what is your address again?... just kidding.

trying to make what I have work reliably... but the colkan is oh so very tempting...

hoppyinca

19th August 2007, 04:56	#1 (permalink)
hoppyinca New Member Current Rebreather/s: MK 15.X Other Rebreather/s: Join Date: Jun 2005 Location: Laguna Niguel, CA USA Posts: 253	PCB wire connection advice needed... (Mk15.x) I apologize for the poor pic quality... I actually have two issues... let me start from the beginning; I have an operating version of this board for comparison. This is a board for a digital display secondary for a Mk15.x (I think Mk15.5 \| Mk16). the wires on the left go to the selector switch and the display. The wires on the right are for the cable from the O2 cells. I am attempting to repair this as a back up, but... there appears to be a section of the circuit which has been scrapped off (see blue circle). On the operating unit there is no break, the circuit connects form the wire attachment to the big-o-clump of solder, as it is the wire connects to nothing in the circuit!... incase you haven't noticed I do not normally repair PCBs... the second issue is that I only have one housing, and no good bendix connections. I would really like the internals to be easily swapped out. So I plan to swagelok the cable to the bulkhead making a watertight seal, but then I would have to solder in the event I need to swap. I am hoping there is some easy way to modify the board so that the wires can easily and repeatedly be disconnected without soldering... some kind of terminal block, but it has to be pretty low profile... here's the pic; digMk15brd_initialState_descrip.jpg any advice would be EXREMELY appreciated... please ask questions if you want to help, but find that I have not described the issue clearly... hoppyinca
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19th August 2007, 10:52	#2 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: PCB wire connection advice needed... (Mk15.x) Hate to say it... you're going to build-in a problem with any sort of connector in there. If the board works, it'll work forever.... and if it breaks, desoldering it is not a big deal. Soldered connections never fail. If it were me? I'd solder it. With that said, I solder in sensors on many rigs too... (not the Mark-15, but....). It's not a big deal. My bet is that any problems you would have with the board would be a result of having corrosion start in the connector you propose to use. Swagelok connector to bring the cable thru the bulkhead is fine. Make sure the wire is the right stuff or it'll collapse. Use the nylon ferrules in a stainless steel Swagelok fitting. Have your weight, just need to get back home to send it. It's holding down my McMaster-Carr catalog on the bench. Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
(Offline)

19th August 2007, 15:43	#3 (permalink)
hoppyinca New Member Current Rebreather/s: MK 15.X Other Rebreather/s: Join Date: Jun 2005 Location: Laguna Niguel, CA USA Posts: 253	Re: PCB wire connection advice needed... (Mk15.x) Quote: (Originally Posted by Dave Sutton) ... you're going to build-in a problem with any sort of connector... I solder in sensors on many rigs too... Swagelok connector... fine. Make sure the wire is the right stuff... Use the nylon ferrules... Have your weight, just need to get back home to send it. It's holding down my McMaster-Carr catalog on the bench. Dave my thinking was the connector would make secondary change out easy/ fast... thinking pre-dive checks on boat, something happened, and needs to be swapped... The cable is the same used by original kit; bendix to the center section, no connection on meter end. thanks for the heads up on the nylon ferrules, i was going to use the standard SS ferrules. thank you thank you... for the weight, what's going to hold the catalog down now? hoppyinca
(Offline)

19th August 2007, 15:46	#4 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: PCB wire connection advice needed... (Mk15.x) Quote: (Originally Posted by hoppyinca) my thinking was the connector would make secondary change out easy/ fast... thinking pre-dive checks Then you need a second complete secondary assembly, not replacement guts for one secondary. Trust me here.... chances of a working system failing approach zero, and if it fails it's failed because it's flooded... changing the guts is not the answer. The original secondary display has a Bendix at the actual primary. You are going to hard wire that, so that's not an option. But: Secondaries normally connect to the center section with a Bendix too...... are you retaining this? If so, unscrew the thing there and change out an entire secondary if you are worried (and I would not be), which means you carry a complete unit including cord. If you are planning on not having a Bendix in the center section..... use a Fisher connector. Don't hard wire the cable into the center section and then think to remedy faults at the display side of the system. Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com Last edited by Dave Sutton : 19th August 2007 at 16:01.
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19th August 2007, 16:02	#5 (permalink)
hoppyinca New Member Current Rebreather/s: MK 15.X Other Rebreather/s: Join Date: Jun 2005 Location: Laguna Niguel, CA USA Posts: 253	Re: PCB wire connection advice needed... (Mk15.x) Quote: (Originally Posted by Dave Sutton) Then you need a second complete secondary assembly, not replacement guts for one secondary. Trust me here... if it fails it's failed because it's flooded... changing the guts is not the answer. Secones connect to the center section with a Bendix...... if you are worried (and I would not be), carry a complete unit including cord. If yor are planning in not having a Bendix in the center section... Dave parts parts parts... I can source a housing, SMI still has some, I have 2 "buldhead plates", but that's it... know of anyone willing to get rid of the "caps"... parts parts parts... this was my initial goal, 'PnP' secondaries so to speak... was thinking more along the lines of the meter (battery not required) failing as the fault, not so much a flood, but I see your point... I would love to have bendix everywhere, but damn those things are EXPENSIVE!!!!! the one buldhead bendix I have has been SSSOOOO molested that is it useless. all but the center #6 pin are missing from the internal side, and someone had tried to 'dig' out more pin after breakig them off, so very sad... hoppyinca
(Offline)

19th August 2007, 16:31	#6 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: PCB wire connection advice needed... (Mk15.x) Quote: (Originally Posted by hoppyinca) parts parts parts... If I were giving advice? Call up Colin, order a Colkan secondary, and move on....... If I were poor? Call up Carl, order a SARTEK secondary, and move on....... if I were really poor? Call up Mark Monroe and order a PP02.com Mark-15 secondary board and build one "in a tube". Shit, build two and you'll save enough to be able to afford all the Lumberg connectors you can use on each end of both. If I lived near me? I'd sneak into my garage and steal one of the analog secondaries that's gathering dust because I replaced them with Colkan's.... (don't do that though or my Dachshund will wake up my Doberman and then you'll be in for a face-licking). All the rest is just a chase that's going to end up unreliable, and just as expensive in the long run. Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com Last edited by Dave Sutton : 19th August 2007 at 16:39.
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19th August 2007, 17:00	#8 (permalink)
hoppyinca New Member Current Rebreather/s: MK 15.X Other Rebreather/s: Join Date: Jun 2005 Location: Laguna Niguel, CA USA Posts: 253	Re: PCB wire connection advice needed... (Mk15.x) Quote: (Originally Posted by iain-hsm) ...copy of the secondary parts list and a parts drawing from the manual.... thank you thank you... hoppyinca
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19th August 2007, 17:02	#9 (permalink)
hoppyinca New Member Current Rebreather/s: MK 15.X Other Rebreather/s: Join Date: Jun 2005 Location: Laguna Niguel, CA USA Posts: 253	Re: PCB wire connection advice needed... (Mk15.x) Quote: (Originally Posted by Dave Sutton) ...sneak into my garage and steal one ... sorry, what is your address again?... just kidding. trying to make what I have work reliably... but the colkan is oh so very tempting... hoppyinca
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