Extending the BFC cable

[Y-my-R]

Thanks, John and Phil!

I did use a 50 foot DB25/data cable for the most recent tests, but it works when used alongside the stock/short BFC cable (I left all the other long cables connected, and just swapped out the BFC cable... and in that config, the long data and PS/2 cables worked with the short BFC cable, but failed as described with the long BFC cable).
Do you think the data cable might behave differently, when a longer BFC cable is in use? I can try again... just had the short BFC cable attached right now.

And Phil... not a stupid question at all, and you're absolutely right, that I should be able to measure on a running system (at least for the wires that actually have voltage on them).
The only thing is, that I try not to stick my hands anywhere, where there's live voltage going on. I shocked myself unconscious a couple of times in my life (back when I still lived in Germany and with 220 Volts), and am glad I'm still alive. Once, I took down the power for a whole studio complex (around 10 studios) by touching one of those old "melting-fuses" (what's the proper name for that?) that was missing the glass on the back... I woke up having a whole bunch of blokes stare down on me while lying on the floor and regaining consciousness, while they were bitching why the power went out (nobody seemed to care about me lying there when they arrived). So, you don't want me around power.

Because of that, I'm thinking to just put a 9V battery on one end and a light bulb on the other, or so, and try to measure if there's a difference in voltage drop between the many different wires in the BFC cable...?

Besides, not all the wires in the BFC cable have power on them, and I can't be certain that there isn't a short on non-power carrying wires, that could somehow still be responsible for getting in the way of booting the console properly. That's another reason why I thought it might be best to apply a low voltage to individual leads, while the cable is NOT attached to a D8B rack unit. Would that be a feasible test?

Anyway... I'm sorry for making this more complicated than it needs to be. But as much as I may know about building or troubleshooting computer hardware, I shy away from handling anything that has live electricity on it - or enough amps to kill me (I'd think that the voltages in the D8B power supply may not be the issue... but there's probably enough amps to do serious damage to my health?).

If I can't figure out a way to measure without a risk of electric shock, I'd probably have to hire someone... or at least get some of these thick electricians gloves, hahaha

One more thing I thought I should try, was to use an entirely different CPU/Rack unit. Maybe there's component differences in different production years, that support long cable BFC cable runs or not.
When I did switch out the whole set of CPU components the other day, I did find that at least the big transformer in there, was a different model in two of the D8B rack units, with different numbers printed on them. Maybe one set has what it takes to power the console with a long cable, but the other doesn't.

Unfortunately, I don't have any more spares that are ready for testing. I guess I'll have to take apart my Win98 D8B rack unit and bring it back to stock condition, to try with the power supply components in that one, next. Probably on the weekend.

If I find anything interesting, I'll make sure to share it here.

Thanks again!

[Phil.c]

I understand your fear of becoming dead as you nearly did before

I would think a 9v battery on one end and a voltmeter instead of a light bulb on the other a better way?

[Steam Radio]

What a great thread and interesting outcome, never thought it was possible to extend the cable but well done to all who did it.

[Jondav1120]

Hi Y-my-R,

One more thing I thought I should try, was to use an entirely different CPU/Rack unit. Maybe there's component differences in different production years, that support long cable BFC cable runs or not.

The only difference I can think of is the old / new motherboard. It is possible that they use different RS232 line driver IC's on the motherboard. I have a feeling that Mackie used a couple of different 5v power supplies in the CPU, as there are two different sets of connections on the power distribution board.

Best regards

John

[Crash]

Hi Y-my-R,

One more thing I thought I should try, was to use an entirely different CPU/Rack unit. Maybe there's component differences in different production years, that support long cable BFC cable runs or not.

The only difference I can think of is the old / new motherboard. It is possible that they use different RS232 line driver IC's on the motherboard. I have a feeling that Mackie used a couple of different 5v power supplies in the CPU, as there are two different sets of connections on the power distribution board.

Best regards

John

I don't recall there being different 5 volt power supplies during my tenure there. I don't see it reflected in any build of material pdfs either. Mackie did source another MB when the Amptron 9000 stock was gone and no more could be sourced, as well as the CPU when that got upgraded to a faster animal.

[Crash]

Have you checked the fuses in your power supply(s) by chance?

I wouldn't be scared to measure the voltage on the pins of the big ass cable. There is not enough there to flatten you, though I do get the sentiment. Somewhere on here, there is a pic of the cable end showing the pins and what they should carry.

[Jondav1120]

Hi Y-my-R,

One more thing I thought I should try, was to use an entirely different CPU/Rack unit. Maybe there's component differences in different production years, that support long cable BFC cable runs or not.

The only difference I can think of is the old / new motherboard. It is possible that they use different RS232 line driver IC's on the motherboard. I have a feeling that Mackie used a couple of different 5v power supplies in the CPU, as there are two different sets of connections on the power distribution board.

Best regards

John

I don't recall there being different 5 volt power supplies during my tenure there. I don't see it reflected in any build of material pdfs either. Mackie did source another MB when the Amptron 9000 stock was gone and no more could be sourced, as well as the CPU when that got upgraded to a faster animal.

Hi Crash,

Sorry, should have phrased that a bit better...what I meant was that the Mackie design guys appear to have kept their options open with the source of the 5V power supply. The circuit diagram for the linear power supply board refers to both Astec and Universal Microelectronics power supplies.

Linear power supply board.JPG (Array KiB) Viewed 2466 times

I guess they never had to use the other option, certainly I cannot recall any posts on here or the old forum that referred to the Universal Micro option.

Best regards

John

[Crash]

Hi Y-my-R,

One more thing I thought I should try, was to use an entirely different CPU/Rack unit. Maybe there's component differences in different production years, that support long cable BFC cable runs or not.

The only difference I can think of is the old / new motherboard. It is possible that they use different RS232 line driver IC's on the motherboard. I have a feeling that Mackie used a couple of different 5v power supplies in the CPU, as there are two different sets of connections on the power distribution board.

Best regards

John

I don't recall there being different 5 volt power supplies during my tenure there. I don't see it reflected in any build of material pdfs either. Mackie did source another MB when the Amptron 9000 stock was gone and no more could be sourced, as well as the CPU when that got upgraded to a faster animal.

Hi Crash,

Sorry, should have phrased that a bit better...what I meant was that the Mackie design guys appear to have kept their options open with the source of the 5V power supply. The circuit diagram for the linear power supply board refers to both Astec and Universal Microelectronics power supplies.

Linear power supply board.JPG

I guess they never had to use the other option, certainly I cannot recall any posts on here or the old forum that referred to the Universal Micro option.

Best regards

John

It's possible that they did use some other supply, but 5 volts is 5 volts. I don't think there would be anything different spec wise. My guess is this was the next supply they would go with if the Aztec became impossible to source and no longer manufactured. That document is from 98, when I was still there, and while the CPU was built on the same production line as the HUI, I don't recall seeing anything other than Aztecs being used....but it has been a while and my memory ain't what it used to be.

[Y-my-R]

Thanks so much for all the responses, John, Crash and Phil!

I'll go in order of suggestion received with my responses, in an attempt to keep things straight:

Phil - I was thinking to put a battery on one end, and a light bulb on the other, so I could measure the exactly voltage going into the cable, and the voltage coming out of it and going to the light bulb on the other end... but maybe there's a setting on the multimeter, where I could do something like that without the light bulb. I just figured, I have to have something for the power to flow to, in order to measure power drop. But maybe I just have to read the instructions for my multimeter for once

John - old vs new motherboard... I was thinking about that, but had dismissed it in my head, thinking that the RSS ports work with the 50 foot data cable, when the stock BFC cable was attached. But maybe I have a logic flaw in that.
Well, when convert my Win98 rack computer back for the test, I'll find out... that one has the new board in it, while the one I was testing with so far, has the old board in it.

John and Crash - About the potential differences in power supplies and the 5V Astec vs Universal Microelectronics... I understand that the latter was likely just an option that wasn't put into production... but I'll try to compare what (major) differences I can find between two different sets of power supplies, when I do the next round of testing.
As mentioned, there's at least a difference in transformer appearance and the numbers stamped on them... but I don't know if they have differring specs... but who knows... maybe the one with the uncommon transformer also has other uncommon stuff in it. I'll take a look, and will report back.

Crash - thanks for the suggesting to check the fuses - that's just too easy to miss. I did look at them already, and the at least visually look OK. But I'll make sure to measure if they actually work... I think at least once, I had a fuse melt all weird, close to the end on one side, where it still looked like there was a wire in there... I'll check that, too!
...and thanks, also, for reassuring me that the power coming from the BFC cable shouldn't kill me. If I can measure with it detached on the D8B end, then sure... I can measure the 5V and 16V wires that end there at the connector (I thought I'd have to test under load... so, with the console connected and powered up, and then measuring from the inside of the console, and THAT, I'm a little scared of... and of measuring inside the D8B power supply in the rack, while it's on).
Anyway... I'll measure the power wires at the disconnected cable for now - that, I'm not worried about.

I was only thinking that my "light bulb" approach above, would have let me measure each of the wires/lines inside of the BFC cable for a possible voltage drop and thus a possible short, where electricity "escapes" somewhere. Not just the wires that have power on them by default. But it should be evident by now, that I have ZERO clue about these types of things, and just speculate and come up with stuff that sounds logical to me... but might not be practical at all.

Anyway... I have a whole bunch of things I can try this weekend. Hopefully I'll get it working.

Thanks SO MUCH again, everyone!

[Phil.c]

There is power flow when you connect a multi meter across the cables, this is what gives you the voltage reading.