Hello all,
when measuring between ground (first pin) and the other pins at J3-J6, I always get 5V at the second pin (first output) only.
This means, LED 1,9,17,25 are _always_ ON, all others always OFF. I’m using the DOUT test.
Can someone help me?
regards,
Sebastian
Hi
you’ve got a fully stuffed (all components on pcb) dout, yeah?
I think the DOUT-test (haven’t used it myself), allows you to select one of (possible) 128 DOUT witch an encoder or inc/dec buttons, meaning when you start the application only the first DOUT is “on”, you have to turn the encoder or press the “inc button” to select the second DOUT (putting output 1 off, output 2 on)
or did you know all this? ;D in that case, did you check voltages before putting in ic’s, are the ic’s oriented the right way?
good luck,
marcel
yeah, it’s fully stuffed.
of course the inc and dec buttons work well, shown on LCD. but the DOUT doesn’t change. always LEDs 1,9,17 and 25 are bright and all the others aren’t. (measuring gives the same result, so there’s no problem with the LEDs or the wiring)
the ICs are oriented the right way, I think. could I rotate them just for testing? so i’ll go checking voltages and maybe get some new 74HC595 s. should the first 8 LEDs with only one IC stuffed, too?
any more suggestions?
Sebastian
Hi,
you could have the same problem like Twin-X had with his DIN module, see http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=troubleshooting;action=display;num=1096139044;start=28#28
(Reply #28 )
Don’t rotate the ICs, this could destroy them!
Yes, the DOUT module works also when only one chip is stuffed.
Best Regards, Thorsten.
hm, there doesn’t seem to be a short. what else could I check? I’ll try a new IC, if I can get one quickly…
I don’t think that another IC will give you better results, because the propability that they are not working is very very low.
It’s difficult to give you some additional tips so long you don’t describe what you’ve already done. E.g., you are writing that “there doesn’t seem to be a short”, but you are not writing how you’ve ensured this. Therefore its unclear if it makes sense to give you some tips for measuring the module, or if the problem could be somewhere else.
Best Regards, Thorsten.
ok, sorry, i was just answering too quickly. I mean, there is no short between the CLK and LD pins of the sockets.
All sockets have 5.00V at pin16-pin8.
All Vs on the output Js are connected.
regards,
spanky
UPDATE:
tried a new IC, everything seems to work now. I’ll test with the LEDs and buttons connected - not only the voltmeter…
thanks for your help!
UPDATE:
found the error. don’t use 74HC165 instead of 74HC595 ;o) i must have been confused when ordering all those parts…
best regards
Sebastian