Crappy Christmas "Laser Shower" projector teardown - Page 1
Forum section: electronics / general

author: Homer J Simpson
author_rank: Super Contributor
timestamp: December 25, 2016, 02:33:18 pm
content: From mikeselectricstuffhttps://www.youtube.com/channel/UCcs0ZkP_as4PpHDhFcmCHyA

author: SeanB
author_rank: Super Contributor
timestamp: December 25, 2016, 06:02:49 pm
content: With the wierd board layout with all the vias I would postulate the PCB manufacturer had a stock of drilled boards for a PCB that size, and had already plated them when the order was cancelled, leaving them with perhaps 1000 predrilled boards that are not usable as is. then the had a sale of these boards to another smaller manufacturer who wanted PCB's for this projector, who had an existing design that needed a similar size board, and used this predrilled big sheet to do the cheap units, as they probably got the boards for the scrap copper cost, and just had to do the rest of the processing, saving around half the cost of the board. Did a redraw of the original gerber files, using component holes where possible, and placing to fit a few variants of the models, making a new frankenstein design that had a minimum of new holes, and isolating unused holes which were not usable at all.Gave then a board for the cheap version and the more complex one at the same ultra low cost, and the PCB fab used up the stock of boards doing this cheaply, recovering a lot of copper in the etchant as well. Then the boards were populated according to the market segment and sold.Quite possible as the PCB fab likely has close relations with a lot of local manufacturers, and they had this cancelled part finished order ( already paid for likely, but they were expecting an extra order instead of the cancellation they got) they hawked around for somebody to buy, or to pay them to finish it off in a slack slot originally scheduled for these boards and now free, with nothing in sight to replace it. Fab got rid of the boards, made some slight profit from etching the copper off and had the free slot paid for. Laser shower manufacturer got cheaper than usual boards, just had to re layout the board slightly to fit the constraints of the scrap boards for this single order batch. They likely only did a single batch of these as well, buying out low cost parts to do the assemblies, making a copy of another manufacturers stuff to capitalise on the surge in the market. Existing product selling well enough, and they came in and cut cost to sell similar ones cheaper and corner a part of this market, then went to do the same again with another thing.

author: Seekonk
author_rank: Super Contributor
timestamp: December 25, 2016, 09:09:26 pm
content: I had one of those given to me that didn't work. Had twice as many connectors. The wall wart was bad. Powered it up with a supply and it seemed OK. Put another wall wart on it and that blew out. There was over a 1A short that would come and go. The board was twice as complicated as that. One laser seemed to be dead. Thought I'll just drive the other laser at lower power constant voltage through a resistor. The other laser color code polarity was opposite of the other. Somehow got confused and hooked it up backwards. Reverse voltage killed it.

author: retrolefty
author_rank: Super Contributor
timestamp: December 25, 2016, 09:15:29 pm
content: Saw this display type for the first time this week. The house directly across the street had two units sticking in his front lawn, one pointing at his white garage door and the other pointing at his front door. The next night the garage door one was dead, two days later he moved the one working to point at the garage. Neat effect at first, boring after awhile. Wife said she saw them on TV asking $50 or so. I'll pass until cooler effects are offered, like maybe CRT type scan of pictures and cheaper then $50.

author: jonovid
author_rank: Super Contributor
timestamp: December 25, 2016, 09:27:29 pm
content: did get a low cost unit red & green 400mw. static switching display type. no moving discs. setup at the windows, the unit seems reliable.

author: GreyWoolfe
author_rank: Unknown
timestamp: December 25, 2016, 09:46:32 pm
content: SWMBO wanted one to light the front of the house up instead of putting up lights. I talked her out of it as one of our dogs would have gone crazy chasing the "dots" shining into and around the house. Glad we passed as these seem to be junk.