Two stubborn d8b's

[captainamerica]

As Phil C. said with respect to oxidation ......I had these issues many moons ago and I had to replace a bunch of ribbon cables.

[Carlo]

I think its a good idea to built some new ribbon cables and female connectors

[Phil.c]

I'm guessing that the wires in the ribbon won't be oxodized, only the bare ones on the spikes in the connectors, so it might be a lot cheaper just to buy connectors and cut the ribbon ends back a bit?

[Carlo]

Yes, You have a point.

[Bruce Graham]

Hey Carlos;
Good to see you posting again, even if your having troubles!
You'll get it sorted.
Cheers
Bruce

[RJH_MUSIC]

Mixer 2 problem could be the result of a bad LPS 152 power supply which supplies + 5 and +5 sense to the console. I had the same problem with my 2nd d8b. It would run for 10 or 15 minutes and then all the lights would go out. The problem is the LPS 152 that power supply is pretty expensive because there are not a lot of them available on the net used. About 3 months ago I bought the last 2 off the Internet and they weren't cheap. About a $150 American each. A brand new one will cost you better than $300. That's what has prompted me to start building a new power supply. I've gone through 3 LPS 152 power supplies in the last year. I buy them 2 at a time now. Last time I bought 2 and 1 wasn't working. I bit my lip because the seller gave me a great price. Not so great I think.. The LPS 152 power supply is the one that stands upright in the power side of the cpu.

Interesting note in the 15 or 20 years that I've owned both the 8 d8b's I have never cleaned or touched the ribbon cables.

[Carlo]

Rebuilding a newer psu would be awesome tell us how it goes pls. Im interested to change mine to a better psu

[Carlo]

Have you tried changing the capacitors?

[Carlo]

I think the meanwell embedded switch mode powersupply smps 5vdc 30A 150W is a good replacement of tge Astec lps152. MEANWELL Model RSP-150-5RS. Check it out and let me know if this is a good replacement pls

[Carlo]

Hey Carlos;
Good to see you posting again, even if your having troubles!
You'll get it sorted.
Cheers
Bruce

Hey Bruce, yes this is the place to sort problems but also to say hello to good old friends. I think i have the PSU (probably the ASTEC LPS 152) failing. Although i cleaned all the d8b's ribbons im getting frozen meters after couple of minutes. The fault was isolated to one of my remote CPU units. The two d8b's do not fail when both are connected to same remote cpu. When i plug them to the other remote CPU i get weird things like meter bridge freezing or a dead console without sound signal. I have to change the PSU of this unit since i dont want to bank only on one. The one that is working is still an old unit.

Maybe someone can answer this for me:

IS the 5v Astec LPS152 responsible to feed good electrical supply for the clock? If yes so this means that the d8b's are failing (freezing meters) due to this power supply.

What is the 16v, 12v, 48v power used for in the d8b and from which power supply unit please?

I would appreciate if someone writes a guide on how to replace the PSU units with modern units.


Thanks a lot

Carlo