Replaced all my Output Board ribbon cables!

[ddvdave]

Well I just got around to replacing my A/B/C/D ribbon cables in my EIII in order to fix the dreaded "relay problem" where the A cable fails to supply 5v to the relay on the output board. (I don't understand why people would want to run a new cable supplying 5v to work around this problem instead of just replacing the ribbon cables).

Anyway, so not only did this solve my output relay problem, it also solved a mysterious problem whereby low frequency sounds output only voice 1 (and this problem did not move with the voice boards), would sound very fuzzy and distorted. It really seemed more like a D/A problem based on the sound, but I was very pleasantly surprised to see that replacing my ribbon cables solved this problem also.

For the forum's reference, I ordered 5 meters of 20-conductor 0.050-spacing ribbon cable, plus 8 20-conductor IDC sockets and 4 strain reliefs (for the output-board side).

Digikey P/Ns:

Qty. 8: AKC20H-ND
Qty. 1: MB20G-10-ND
Qty. 1: MB20G-5-ND
Qty. 4: ASR20-ND

Plus I made sure to use a proper IDC crimping tool!

As we all already know with our beloved EIIIs, it all comes down to the poor IDC connectors!

-Dave

[ddvdave]

And... as is so typical with the EIII... I got everything put back together after replacing the 4 ribbon cables and none of the sliders/pots worked.

I found that I have the dreaded loose card-edge connector problem on the analog card slot on the motherboard. I guess I'll try some de-oxit spray and a wire brush first. I would hate to have to replace the card-edge connector on the motherboard as that's an awful lot of desoldering!

Has anyone attempted that?

-Dave

[dr.c]

Hi !

The problem is that I will save your realy problem only for a while.
The best is to solder a wire (yellow, if possible) from pin 8 of IC3 on the jack board, untill the +5V coming from the power supply, one of the yellow wires. This is the +5V, don't make mistake, please. Look at manual, page 159

[ddvdave]

The problem is that I will save your realy problem only for a while.

I'm not sure I understand. You don't think the quality of today's IDC connectors with improved metal sockets that provide a secure contact with the circuit board header would be a long-term fix?

-Dave