NedMan
(Ned Hill)
December 10, 2021, 11:50pm
1
(Edit: Fair warning, this is a long story with many twists and turns. With a bit of a cautionary tale, or two, thrown in if you will.)
Ok need some help. Just went to turn my laser on and nothing happened. Checked the fuse at the plug it was good. Checked the AC power at the LPS and it’s getting 125V AC. So something is wrong with the LPS.
Worst possible timing for me right now. Ordered a new one from Amazon just in case for delivery Monday.
Any ideas on what to check? @donkjr
tomatsu
(tomatsu)
December 10, 2021, 11:55pm
2
Is there continuity between G and P?
Do you get anything on the 5 V and 24 V rails?
NedMan
(Ned Hill)
December 10, 2021, 11:58pm
3
Showing 20M ohm between L&P. Nothing on on the 5V or 24 rails.
NedMan
(Ned Hill)
December 11, 2021, 12:03am
5
Opps getting myself mixed up. 0 ohms between G&P. So continuity.
NedMan
(Ned Hill)
December 11, 2021, 12:11am
6
The internal fuse is good.
1 Like
HalfNormal
(0.45 NACL)
December 11, 2021, 12:11am
7
Did you check the fuse that is IN the power supply?
1 Like
HalfNormal
(0.45 NACL)
December 11, 2021, 12:14am
8
Ha! You answered while I was asking!
1 Like
NedMan
(Ned Hill)
December 11, 2021, 12:14am
9
Going by @donkjr LPS trouble shooting guide it looks like it’s just bad.
I got to S
1 Like
HalfNormal
(0.45 NACL)
December 11, 2021, 12:22am
10
That’s why I keep a spare around. You never know when they will crap out.
1 Like
NedMan
(Ned Hill)
December 11, 2021, 12:24am
11
Yeah, I should have had a spare on hand.
donkjr
(Don Kleinschnitz Jr.)
December 11, 2021, 12:28am
12
Is the green and red led on the pcb illuminated?
Does it fire with the test button on the supply?
NedMan
(Ned Hill)
December 11, 2021, 12:40am
13
Nothing lights up and no response on the on board test fire button.
NedMan
(Ned Hill)
December 11, 2021, 12:58am
14
So going by your blog, it’s possibly the DC power supply PWM controller?
Usually the Big fat Schottky diode that delivers the 24V DC blows out. Changed mine about 10 times
The schottky diode has just a rating of 1A so maybe use a faster recovery spec Schottky with higher current?
1 Like
donkjr
(Don Kleinschnitz Jr.)
December 11, 2021, 1:35am
17
Yah but it did not blow a fuse.
And no green led means LV side is dead…
I know, I have the same issue. Never blows a fuse, just the schottky diode. I don’t even bother to desolder the diode from the PCB. Just cut off the leads and solder the new one directly onto the old leads.
donkjr
(Don Kleinschnitz Jr.)
December 11, 2021, 1:39am
19
@NedMan you can snip one side of the diode and then measure it… for open/short.
No burn marks anywhere???