cannot get channels to fire correctly

[trevorgreen]

I am using a grinch board and vixen v2. I seem to have a problem in that when I want to turn channel 1 on it will not turn on unless I also turn channel 2 on. Likewise for channel 2. I need to turn on channel 3 as well as channel 2 to turn on channel 2. It ooks like if I want to turn channel x on I have to turn channel (x+1) on as well to make channel x work. I am using standard olsen 595 plugin. It is driving me crazy, can someone help me please?

[NogginBoink]

That does indeed sound odd. Can you tell us how you tested this and arrived at this conclusion? Perhaps you're misinterpreting some of the information you've gathered?

[ulto]

This is the exact problem I am having.

[trevorgreen]

I just have a simple test tool with led's. When I plug it into any port and then test the channel, I have to activate both the channel it is connected to and the next channel for the led to light up. it is just odd, I have checked everything and cannot find where the problem lies.

[ibby]

How are you powering you grinch? Do you have a common ground between the Grinch and the PC. I have found this to help.

Also how about changing the chip 4 with chip 1 and see if you have a bad chip.

Ibby

[toodle_pipsky]

Sounds like a similar problem I had months ago trying to get a Ren-C/Grinch combo to work. I'll have a dig and see what the deal was. However if you have just a Grinch having that problem, the info may be irrelevant. Tell me, is it just a Grinch you are running?

[bmcgeeny]

I am using a grinch board and vixen v2. I seem to have a problem in that when I want to turn channel 1 on it will not turn on unless I also turn channel 2 on. Likewise for channel 2. I need to turn on channel 3 as well as channel 2 to turn on channel 2. It ooks like if I want to turn channel x on I have to turn channel (x+1) on as well to make channel x work. I am using standard olsen 595 plugin. It is driving me crazy, can someone help me please?

Sounds like a cableing problem. May be ground.
If you have no ground and you turn channel one on, nothing will happen. Turn channel 2 on and it acts like a ground for channel 1 and comes on.

Other possibility I had was the data voltage is too low to trigger your chip.

Alegro or MBI?

The Allegro's are much more sensitive.

[trevorgreen]

thanks for all the advice. I thought about ground but it all looks correctly wired. I am using MBI's. I am powering the grinch from an old PC ATX power supply.

[trevorgreen]

How are you powering you grinch? Do you have a common ground between the Grinch and the PC. I have found this to help.

Also how about changing the chip 4 with chip 1 and see if you have a bad chip.

Ibby

I replaced the chips. However, the problem happens on all ports so it is irrelevant which chip is being used. I will try the common ground, but I am using a laptop so it may be difficult.

thanks

[Virtus]

Can you turn ON channel 4 if channel 1 is ON? Do they have to be sequential or is that all you have tried? What about channel 16 to 17 when the output spans chips?

[jpb]

Check your grounds.

Check the bios of your parallel port.

It is possible that the signal high voltage of your parallel port is too low in comparison to your 5v. The Allegro being "more sensitive" can cope with lower port voltages. I originally got around this by putting a diode in the 5v power lead to drop the voltage by .6v which brought it closer to the 4v being put out by the parallel port.

You will find other posts mentioning bios and voltage levels if you do a search.

Jon

[trevorgreen]

Can you turn ON channel 4 if channel 1 is ON? Do they have to be sequential or is that all you have tried? What about channel 16 to 17 when the output spans chips?

I cannot turn 4 on if channel 1 is on. I can ony light it if I pout channel 5 on. it only happens in sequential channels. for channel 16, channel 17 has to be on otherwise channel 16 will not light.