DT25 help

[colouredmirrorball]

Could it be a ground issue?

Have you tried taking all elements off and test them without being connected to each other by a base plate?

[neutrino]

Hey Doc, gave the board a good blast of compressed air and still doing the samething.

Coloredmirrorball, the only thing still connected to the baseplate is the PSU. I removed the driver amp from the baseplate. The scanners also are not connected.

Cheers
Rich

[polishedball]

Have you measured the input voltage?

[neutrino]

Just double checked the input voltage to the regulators. The PSU is giving out bang on +24V and -24V.

[badger1666]

hi have you checked the jumper pins have good contact i found mine were loose
and gave me problems untill i replaced them as for the led not working , have you checked the led is ok ?, one of the one's on my dt40's does not work,but the scan set works just fine

reading back the big one you says getting hot is the amp itself, was every thing plugged in when you found it was running hot ?
if it was it might be knackered, or somthing else is causing it to run at full load,?
one thing you dont do is touch the galvo mirrors while its powerd up. just a gentle touch can cause it to draw a lot of current trying hold the position that its supposed to be in, and break any weak parts in the chain,

[neutrino]

Hi badger,

I will check the jumpers a bit later on today. What will be the easiest way to check the LED is functioning or not? I am sure it was working when I received the scanners.
Nothing was plugged in to the driver when the amp chip got hot except for the PSU. The mirrors were only touched briefly to check there was friction and this was done on a previous test, not this one when measuring output voltages from the regulators.

Cheers
Rich

[badger1666]

hi
have you tested the amp running with an input ? ie scanning
somtimes its not good to run amps with the input floating they can pick up interference
and oscillate run it up with the inputs + - tied to ground and see if it still gets hot?
also never run the amp with out the galvos attached, and all ways make sure the x and y cables dont get mixed up the galvos are tuned to the amp get the the wrong way around and theres a good chance the whole system will get in to a self oscillation
and kill the galvo, i know i made that expensive mistake once
in the time that you have had yours did you ever hear the galvos squeal like a pig ??
i hope not

Hi badger,

I will check the jumpers a bit later on today. What will be the easiest way to check the LED is functioning or not? I am sure it was working when I received the scanners.
Nothing was plugged in to the driver when the amp chip got hot except for the PSU. The mirrors were only touched briefly to check there was friction and this was done on a previous test, not this one when measuring output voltages from the regulators.

Cheers
Rich

[neutrino]

have you tested the amp running with an input ? ie scanning
somtimes its not good to run amps with the input floating they can pick up interference No I left these floating - I will try it with the inputs tied to ground and see what happens

and oscillate run it up with the inputs + - tied to ground and see if it still gets hot?

also never run the amp with out the galvos attached, Wow, this I did NOT know. I hope this hasn't caused further problems

and all ways make sure the x and y cables dont get mixed up the galvos are tuned to the amp get the the wrong way around and theres a good chance the whole system will get in to a self oscillation
and kill the galvo, i know i made that expensive mistake once I am pretty sure I have not done this as of yet, there is always a first time though!!

in the time that you have had yours did you ever hear the galvos squeal like a pig ??
i hope not I only wired everything up to see if it was all working. Probably ran them for a couple hours total (driver was heatsinked) and no abnormal noises

I think I may send them to DZ to have a look at. DZ, PM sent

Thanks
Rich

[DZ]

All fixed. I found that the trace between the output of the +V regulator and the SMD cap was split. I also see a small burn mark around the +24V pad on the input connector. Not exactly sure what happened, but it's working now.

[neutrino]

DZ you are a superstar!! I really should have looked closer at the board. Maybe time to buy a magnifying glass.

Thank you so much. You'll have to let me know what I owe you.

Cheers
Rich