Moving light maintenance

[steve1981]

I doubt the big chip is a DMX chip, it'll be a slave microcontroller. The proper generic part number will be under the sticker, and usually starts AT..(Atmel), PIC..(Microchip Corp), and so on. However, as you've probably guessed, they'll have an OTP ROM section making them unique. Are you kitted out to copy/burn OTP ROM? You'll have to have a good sample and then pray that the copy protect bit isn't set....they usually are.

 

The driver ic numbers will be under the heatsinks which will be bonded with heatsink epoxy..making removal difficult. Try a short sharp tap to break the seal. You may just then be able to read the number!

 

It may of course be neither the micro or the drivers..but a peripheral component eg leaky cap.

 

I hope you have patience and willing!

 

Please post a picture of the whole light, it may be the same as a 'branded' one and if we recognize it, you may be able to source spares from the appropriate UK distributor.

 

The light is here... http://www.yagang.com/en/product_item.asp?productid=63

 

I am not set up to copy chips and wouldnt have a clue how to to be honest. I have just managed to get hold of a good slave microcontroller. Upon testin earlier, I found that both chips are different, have different numbers underneath, and contain different DMX channels for the motor drivers that they are connected to. So... 2 of these chips have gone, and that has in turn taken out some of the motor driver chips connected to it. I think it was the light that had water damage in before as the toher one only blew when I put it in that one to test it. Where can I get copies made of the chips and is it expensive?

[David Duffy]

The micro-controllers (with the sticker) will almost certainly have their CP (copy protection) bit set. This means you (or even the manufacturer) can't read them to copy. They are programmed & verified before the CP is turned on.

 

Often a motor or wiring fault will damage a driver chip, which in turn sometimes whacks the latch chip (smaller surface mount chips in pix) or even the micro-controller. There's nothing the micro-controller can really do to damage the latch or driver chips.

[steve1981]

The micro-controllers (with the sticker) will almost certainly have their CP (copy protection) bit set. This means you (or even the manufacturer) can't read them to copy. They are programmed & verified before the CP is turned on.

 

Often a motor or wiring fault will damage a driver chip, which in turn sometimes whacks the latch chip (smaller surface mount chips in pix) or even the micro-controller. There's nothing the micro-controller can really do to damage the latch or driver chips.

 

oh. Sp its more likely for the fault to have come from the other end than what I thought. Right. Well I have managed to get a few bits from another light with different problems including the magnetic sensor so I'm gonna have a bash this afternoon, I'll let you know how I get on.

 

Cheers David.

[steve1981]

So is it the whole unit not responding to DMX, or just the functions plugged into one of the side PCB's?

 

If the former, the DMX input chip is likely to be dead. If the latter, a faulty micro or (more likely) broken wiring going to the side PCB.

 

Only the DMX to one side is not working. As far as I can tell, its not the motors or the wiring as I put a good pcb in and a good chip (from the toher side so the DMX channels were the opposite way round if you know what I mean) but everything worked as it should. I think it is just the driver chips and the micro. BUT... the I need to find out why it went in the first place which aint prooving to be easy.

 

Can you think of any reason why, if the unit was esposed to a bit of water in its past, why it would cause these chips and drivers to go? (Other than water on the actually chip itself of course.)

[Brian]

Can you think of any reason why, if the unit was esposed to a bit of water in its past....

Didn't mention that before did you?

 

If it was pure water then it's unlikely to have been a problem. However, the slightest amount of contamination will cause corrosion and short circuits which can damage chips and the PCB itself.

[KevinE]

Only the DMX to one side is not working

Forget about the DMX. The DMX doesnt reach the arm pcbs, its processed by the main CPU in the base.

 

At this stage, you should be using the internal test mode.

 

It sounds like you're a little out of your depth to be fault finding on a moving head..they're complicated things esp. with multiple faults! As a learning curve you might find it rather fruitless and frustrating.

[KevinE]

There's nothing the micro-controller can really do to damage the latch or driver chips

 

I dont agree.

 

If the pwm goes screwy or disappears it could just turn the driver hard on and the current through the motor winding could pop the driver.

[KevinE]

Is it about time these threads about poor steve's duff chinese movers were merged? There's about 3 topics going all about the same thing.

[steve1981]

It sounds like you're a little out of your depth to be fault finding on a moving head..they're complicated things esp. with multiple faults! As a learning curve you might find it rather fruitless and frustrating.

 

I find thats the best way to learn.

 

A concurrent post has been automatically merged from this point on.

 

Only the DMX to one side is not working

Forget about the DMX. The DMX doesnt reach the arm pcbs, its processed by the main CPU in the base.

 

I have narrowed it down now by swapping the chips and the pcb's around and seeing what works with what, and found that it is the big chip on the PCB and all of the 3 output to motor drivers. Still got some more testing to do though.

[Andrew C]

Moderation: As we had three threads running on maintaining the same lights, we've merged them. We hope that all remains clear; if not let me know and I'll try to sort out confusion.

[David Duffy]

There's nothing the micro-controller can really do to damage the latch or driver chips

 

I don't agree.

 

If the pwm goes screwy or disappears it could just turn the driver hard on and the current through the motor winding could pop the driver.

 

Well, it doesn't directly damage the following chips. We're splitting hairs here! :)

[KevinE]

I find thats the best way to learn.

 

Yeah, I suppose so! But it's also a good way of needlessly damaging chips that you may have no way of obtaining!

 

I dont recognise those lights, though did you post a pic of them a few months ago on BR asking a similar question about spares? Silverstar are more known for their cheap DJ lasers, badged-up with european brand names including Soundlab and EU-Light. The world of faulty chinese movers is an ever-growing minefield. Maybe getting a donor machine off ebay may be the solution?

[Carlos Mendoza]

Hello, the programable microprocessor came programmed from the factory, and are copy protected, by the label, I´m sure the factory is Silver Star, you can buy from them the spare parts, can contact to Ivy Chen at ivychen@yagang.com , for the DMX problem, check the resistors near the connector and inside the connector the pins, if order a processor or a board (are very cheap), mention for which side because processor has different program, for pan and tilt hall magnetic sensors looks like the Robe´s but Robe´s don´t work on this brand, needs the original, I hope these words can help to you, best regards.