burner question

[carsten_the_dane]

Changed the subject of this topic a bit, since my original problem didnt have much to do with my problems now. Please read on...

[carsten_the_dane]

well i skipped that step and bought 2 nine volt batteries.

But there is no light in the leds.

Could i possibly post pictures of my board here, so that someone could check it out for errors. Because i dont know what to do now.

Carsten

[carsten_the_dane]

:-X i think i fried the LM317 voltage regulator.

I had accidently switch around the capacitor and the "voltage testing pins". Whoops

It almost caught fire  :-\

How on earth can i troubleshoot my board now. Maybe it was just the regulator that died on me, but perhaps all the parts got fried  ???

Nice to know what you´re doing

carsten

[carsten_the_dane]

Lol. im getting a reading that says between 0.02 and 0.05 volts.

[carsten_the_dane]

Electronics is completely new to me. So if you could please help me on this.

Today i changed the 100uF 16V rectifier with a new one. Its a bit different; it says 100uF and 100V, i hope this is not a problem.

I also changed the first voltage regulator LM317 - this one is changed to one called TL317. The man in the shop said it was the same. Is this a problem?

I think i have manage to find the problem is with the LM317 (now TL317), where the voltage drops from about 9 (not quite 12.5) to 1,5.

Any suggestions would much appreciated?

Thanks

Carsten

[carsten_the_dane]

Using the multimeter i was measuring volts, particularly looking at the TL317 (LM317 in the schematics, read above).

when i make connection between what i would call finger 1 and 2 on the TL317, the green light lights up quite clear. What could this mean?

(finger 1 and 2 being first to the right and second to the right, looking on the flat side of the TL317)

[TK.]

It's very dangerous to short the legs of a semiconductor, this mostly leads to damage of this part, and if you have bad luck, also of the surounding parts. This doesn't mean, that the other parts are damaged now, but nobody can really tell you, if they still working or not - this can only determined by experts. :-/

I think, the current situation is: when the green LED lights up, then the 5V domain (behind the 7805) is working ok, the problem must be somewhere between the LM317 and 7805 (see schematic). Yes, it doesn't matter if it is a 100uF/100V ecap and a TL317, they both should work.

You are writing:

I think i have manage to find the problem is with the LM317 (now TL317), where the voltage drops from about 9 (not quite 12.5) to 1,5.

where do you measure 9V? Before or after the LM317 (see schematic: "before" is the I pin, "after" is the O pin), voltages have to be measured against ground.

Or more interesting: which voltage do you measure at J1, which at LM317:I, at LM317:O, at J2?

Best Regards, Thorsten.

[carsten_the_dane]

Hi

First of all, thanks for moving the post, i didnt want to cross-post.

And also thanks you for taking the time helping me.

Here are the measures:

J1          = 8.92

LM317:I  = 8.91

LM317:O = 0.13

J2     = 1.38

[TK.]

Alright, this explains everything! :)

At J1 you should see a voltage of ca. 18V, it seems that you've connected the 9V blocks in parallel, and not in serial. This means:

one pin of J1 -> 1st 9V block (-)

1st 9V block (+) -> 2nd 9V block (-)

2nd 9V block (+) -> second pin of J1

It's like a chain between the 9V blocks and the power input J1 of the burner module.

Best Regards, Thorsten.

[carsten_the_dane]

:-X whoops.

Ok, the setup works, i get green light and a measure on j1 and j2 at 14.5

But it puzzles me that i should connect the batteries at J1 and J2, at the pictures of you making the burner, the power clearly comes from J1 only?

[TK.]

Arg! This was an error, please remove the connection at J2 (hope this didn't fry the LM317), it should be connected to the second pin of J1

Best Regards, Thorsten.

[carsten_the_dane]

thats to bad. cuz now im getting no read at all.

I connect the (-) from the battery to the pin closest to the LPT connector.

[TK.]

I fear that my wrongly specified connection (+) -> J2 fried your LM317 :-(

I'm really sorry about that, I was typing the message too fast. You need a new one - what is your postal address, I will send you a well tested LM317 for free

Best Regards, Thorsten.

[carsten_the_dane]

I appreciate it, but there is no need for that. I dont live so far from an eletronik store.

Even if it is fried, shouldnt i be able to get a reading before the LM317?

[TK.]

You don't measure any voltage between the two pins of J1? So, how did you connect the batteries then?

Do you read a voltage when the LM317 is removed from the PCB?

Best Regards, Thorsten.

[carsten_the_dane]

My bad about the 0 volts at j1. New 317, New measures:

J1: ~ 18 volts

317: I = ~ 18 volts

317: O = 0.14 volts

J2: 1.41 volts

This time i couldnt possibly have done anything to break the 317. No green lights either.

So whats your advice?

(EDIT): Been spending some time going over the schematics. And i havent been able to find any errors in my setup.

Did i say that i have removed the b80c800 rectifier, and just uses a bridge. but than shouldnt mean anything, right?

[carsten_the_dane]

Here is a picture of my board, with some additional comments. You can see how i have placed to LEDs, and if there are any problems with my setup otherwise. The little blister on the voltage regulator is because this image is from before i moved the lm317, as explained earlier in this thread.

I hope you dont get to confused by my drawings  :-\

[TK.]

Looks correct, I don't know what else could be the problem. W/o the bridge rectifier you have to take care about the polarity, but I guess that you always did this?

Best Regards, Thorsten.

[carsten_the_dane]

I think when i had bad results i had tried changing the polarity, just to check if that might be the fault. Could this cause other compoonents to malfunction? - But generally i have been using the pin closest to the lpt as negative and the other as positive. I will put the recitifier back in place, so theres no doubt.

Anyway, i was thinking of just bying all components again (except the sockets), and start over.

Could it be a shortcircuit on the other side of the board. - I have checked but havent found any that i could see.

Just to make sure: theres no polarity on resistors and ceramic capacitors, right?

Well. Thanks again for taking some time to help me

Carsten

[docbrown]

Just to make sure: theres no polarity on resistors and ceramic capacitors, right?

Right!! Except for electrolytic capacitor.

[carsten_the_dane]

Could you please take a look at the datasheet found on this page http://www.datasheet4u.net/html/T/L/3/TL317_TexasInstruments.pdf.html

As far as i can see, the I,O,A placement on the TL317 is different from the schematics found on ucapps.de. - Or what  ???

[carsten_the_dane]

Sorry my mistake again ;D

Though the connections are made right i have been measuring at the wrong places. I had changed O and A around in my head. So the measures should be like this:

J1: ~ 18 volts

317: I = ~ 18 volts

317: O = 2.1 volts

J2: 1.41 volts

Dont know if it changes anything

[carsten_the_dane]

NOOO (or maybe yes) - one week of troubleshooting all because i didnt know what a trimpot was  :-X

Well, that will teach me to read about all components and read through all documents before starting the "real" midibox project.

Its working now, and i feel sorry that i have wasted your time like that.

Carsten

[carsten_the_dane]

About the red LED. Should it be 12,5 - or the same as before plugging the burner into the computer?

The documentation is a bit vague.

[TK.]

Before P18 doesn't control the MBHP_BURNER input lines, the status of the LEDs is undefined

So, it's time to connect the burner with the PC, and to use the debug window of P18 to check the voltages.

Best Regards, Thorsten.