@charlie54 You’re in luck! I just managed to fix it a few days ago. Apologies if you’re a bit more experienced at repairs and this is a bit dumbed down for you - but this was my process:
I basically used voltage injection to find the shorted component (there are just too many capacitors to test and my multi-meter was not good enough).
I removed all the connections to the motherboard apart from the main power connector (which you have the arrow pointed to in your image) and placed some kind of protective vinyl sort of mouse mat underneath the board to prevent it shorting against any of the metal components beneath. I then took the grounding wire that is attached to the motherboard near the speaker and screwed one end into the chassis and the other onto one corner of the motherboard so the board remained grounded.
I then plugged the projector into the wall outlet and gently ran my hand over the powered on board (keeping well away from the power supply), to see which of the components on the board was heating up due to a short. I tracked it down to a switching voltage regulator (part of a local power supply or a buck converter I believe), which was getting red hot to the touch. I was able to take a picture of the component with my phone, blow it up on the computer, find the part number, and order one (ive linked it at the end of the post).
The chip is the flat square black chip just to the right of my finger in this image. A different component might have shorted on your board, but it might be a good place to check.
Process to repair
I spent some time watching tutorials on how to solder surface mount components like this tiny regulator, and then ordered the relevant parts to repair:
- A gas soldering iron (my soldering iron was old and crap) which also had a hot air blowing function.
- Cheap tweezers
- No-clean Flux
- Solder paste
I was able to use the hot air gun to heat up the chip enough that I could prise it off the board but in the process managed to literally blow away a couple of absolutely microscopic capacitors that were on the board nearby. I managed to find all but one of them and returned them roughly to where they belonged. I then blobbed some no-clean flux and a tiny bit of solder paste on the board, and tried to position the new regulator that I’d ordered. It took a few attempts and it still looked a little wonky to me when I left it. But I tried powering it on and the projector booted up, straight back to fully working.
- If you’re new to soldering SMD components, be wary that its flipping hard if you’re a complete novice
- Be super wary of where you’re pointing your hot air tool as the temperatures needed to get the chip off were plenty hot enough to melt solder in the nearby area causing components to literally go sliding off the board
- Take the best quality pictures you can of the area before you do any soldering, so you can return things to their correct place if things go wrong
- Also finally and slightly unrelated - I stupidly didn’t realise the connectors for the ribbon cables for the optical engine were ZIF (zero insertion force) so I was ramming them into the connectors a couple of times before realising you’re supposed to flip up the back of the connector to release the ribbons. If you are able to get your projector powered on but the image is discoloured, you’ve probably not seated one of the three ribbons correctly, they’re quite finnicky but once seated properly you should see a correct image
Voltage injection (and this whole series actually): https://www.youtube.com/watch?v=EWuzmIz7...
Soldering SMD components with hot air: https://www.youtube.com/watch?v=rgcupYOn...
The chip you need to order: https://www.mouser.co.uk/ProductDetail/5...
P.S: If you’re UK based, I have a spare one of these chips so can send it you out a bit quicker than waiting for it to arrive from Texas.
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