I burned the BURNER

Testing/Troubleshooting
1

Burner: hand made, on a etched pcb(ordered from a local etcher)

Power suply: 22V from a PC AT power supply [+12/-12]

What happened: I connected the power supply to BURNER and trimmed the voltage to 12.5V +/- 0.03.

Then I [literary] plugged the burner to LPT and got some fireworks. Dunno what happened.

FWrks came from a pcb line that connects the far out power pin to the recitifier so I got that fixed by

hard wireing and now what do I get.

I plug-in the burner into LPT [green LED on] and turn on the power supply, the green led dimms, PSu’s fan starts

and then just stops [it’s like the short circuit protection]

I’m getting thiese results with and without the 74HC14 plugged in. Can anyone help me, I don’t know

what I may have fried, why did this happened or what to do, what to unsolder, check, replace…etc.

Tnx ppl.

[i intend to post my Frontpannel design thiese days, just to get this pic flashed and test the whole

setup, hope to get this enigma solved soon.]

2

Hi,

two more questions on that:

  • Do you use the same powersupply for PC and Burner?

  • How did you get 22V out of the power supply (Connection)?

I also think you have built a shortcut. Thats why the fan starts and the ps stops working.

greets

Doc

3

No, PSu is from an old P1 and burner is plugged in my new PC.

The power connection for AT motherboards have gnd,gnd,+12,-12,+5,+5 on one of the

conecctors [there is two] so I used +12v and -12V.

A shortcut…I doubt, bkz, when the burner aint connected to the LPT the PC ps works fine

and I can adjust the woltage & stuff, but when I connect it to the LPT it dies.

BTW: What are the odds that some TR or C is fried? I mean there was some large current

going trough that pcb line (thats why it fried (it’s quite thin))

4

dude, watch out  :wink:

on the burnerschematic pdf there are 3 options;

  • 15V DC (in this case bypass the rectifier)
  • 18V DC (2 * 9V batteries with or without rectifier)
  • 15V..20V AC

the psu you got gives DC; but the voltage between the two poles u used isn’t 15 or 18 but 24! so first get your voltages right (why not use 2 batteries) then you can see if it still works

cheers, marcel

5

Basically you are trying to ground the -12V line of the P1 PSU with the other PC’s ground. Don’t do this, and don’t try to remove the ground from the PSU, it will become dangerous.

Instead, use batteries for this - they have a ‘floating’ ground so what you are trying to do (use only the voltage difference but not the absolute voltage value) will actually work.

Regards, ilmenator

6

Huh, oook, actually it is exactly 22,5V but ok, I’ll try wth the batteries. Makes sense.

I checked the active components today, they show fine state…we’ll see if batts do

the trick.

Orderlist:

Instead of the two batteries, a AC or DC power supply unit can be used, which delivers at

least 15V (and not more than 25V!) - such devices are hard to find, therefore batteries are

listed here.

This is where I got the 22V idea please change this line in mbhp_burner_orderlist.txt if it is not

correct to feed so much Voltage to the burner.

7

Huh, oook, actually it is exactly 22,5V

That’d be after the rectifier yeh?

8

You might also check any existing universal 1.5-12V Power Supplies and measure the Voltage with a Multimeter. I found more than one that has about 15V while it should actually have 12V.

(I always measure before connecting anything, 'cause I don’t trust the printed statement)

I got problems using two (fresh) 9V-batteries; never reached the required 15 Volts ???

However, I burned very smoothly with these “factory-pimped” psu’s ;D

Regards, Michael

9

@stryd_one: What do you mean after the recitifier? Like, to bypass it?

I wasnt lefting the recitifier out, it was connected to ~ pins

Yeah, tnx Michael, I’ve read that somewhere but this is the only [reusable]

power source that I could find and not pay for it. :slight_smile:

10

I payed 3,- EUR for that supply (@Reichelt) :wink:

And the right power is elementary as you see. A “burned” PC costs you hundrets of bucks and a “burned ToS” costs your life… don’t spare at the wrong end!

:wink:

Regards, Michael

11

@stryd_one: What do you mean after the recitifier? Like, to bypass it?

I wasnt lefting the recitifier out, it was connected to ~ pins

Well you’d have 12 + 12 = 24, as was said to you, you said it was 22.5, I’m guessing that is because there is a voltage drop across the diodes in the rectifier, and you have taken the measurement from the circuitry after the rectifier.

12

Bought the freaking batteries, fixed one bad soldering issue and flashed, verified…let’s power

the core. BTW: I’ve found out that alcatel charger declared as 12V has 16V output :-\

And I’ve “invested” batteries that won’t b used ever again(instead of buying 2 pots).

Thnx ppl for helping out.

13

BTW: I’ve found out that alcatel charger declared as 12V has 16V output :-\

bingo. 2 points to audiocommander :slight_smile:

14

Oh, no, It’s just that not every PC PSU outputs the Voltage as declared, this one had 22,5 on the connector wich means that the actual output vas +11.25/-11.25 instead of 12.