Adding Extra VGA connector to Dell 3400MP Projector

Since M1-DA to VGA cable is quite expensive, we have decided to add extra connector to our Dell 3400MP Projector so we could just use common male to male VGA cable.1st thing to do is to know the connector pin-out. For VGA connector we have 15-pin connector.Cable = MALE and Projector = FEMALE.Next, the M1-A connector (AKA M1-P&D Plug) A lot of pin. :-)Cable = MALE and Projector = FEMALE.Internet research tell me that only 7 connections are needed in order to make this work as below#wiringTable{width:100%;border-collapse:collapse;}#wiringTable td{border:1px solid grey;text-align:center;} > VGA pin# M1 pin# Red 1 C1 Green 2 C2 Blue 3 C4 RGBGround 6,7,8 (join) C5 HorizontalSync 13 ...

Read more »

Troubleshooting Remote Controlled Ceiling Fan

Last week, I came across 2 different model same brand dead ceiling fan. Both models are remote controlled model. Symptom quite similar.The first model comes with 7 speed but I can only see only 5 TRIACs on the board. Not sure how it works.Meanwhile the second model comes with 3 speed and 3 TRIACs available on the board. I assume 1 TRIAC for 1 speed.While troubleshooting they look like their µC don't have enough power to start. The buzzer give something like repeating click sound. I did measure the µC Vdd/Vss and found out that the voltage is less than 5V.After a quick search at Google, lead me to aztronics . Similar symptom. So I give them a try.Desolder the capacitor and measure. Binggo! All caps (regulator part) value is less than they should...

Read more »

HP TX1000 Entertainment Tablet PC GPU Fix

A friend of mine ask for a favor to take a look at his HP TX1000 Entertainment Tablet PC blackout LCD problem. I have no idea on how to fix this until I found below video.Instead of using bulb, I used a heat blower to re-flow the chip.From my observation, there is a the gap between the GPU and the heat sink was join by a burned thermal conductive silicone sponge.I replace this with an aluminum foil folded a couple of times to get just the right thickness.After reassemble it back together and now, the moment of truth, Hey! it works! :-)Thanks a lot jasonshay2. You really save my d...

Read more »

P16PRO40 programmer strip board layout

What is P16PRO40? It is a programming tool for several types of PIC micro controller. I'm not sure the origin of it, but I found it here at http://www.winpicprog.co.uk/ while browsing. The schematic can be found here at http://www.lpilsley.co.uk/pdf/p16pro40.pdf.Since I saw a several request for P16PRO40 strip board layout, so I decided to share it here.My PIC programming tool is a strip board based (AKA Veroboard). It is not as compact & neat as the commercial programmer but guess what, It took only 2 hours for me to built it from my electronic junkyard, except the 74LS05 and of course the strip board it self. Use normal IC socket if you don't have a ZIF socket.I have made some modification to the circuit to match what I can find on my...

Read more »

Fixing a Mouse Double Click Problems

Have you ever experience a bad optical mouse? It went double click action whenever you did a single click action? At first, I try to Google for answer but none of them help. I’ve tried every combination of settings but the problem doesn’t go away. I really suspected there must be something wrong with the circuit. After I made a conclusion that it is a mechanical related issue (maybe the switch it self), I replace the switch from an old mouse available.Unfortunately the problem is still there. This is dangerous since you might drag a folder by accident and move it into another folder. This problem always happening to a first time touch-pad user with tapping function turned on.So next I’m thinking it maybe related to a noise in the circuit. So...

Read more »

555 Timer-Based Flyback Transformer Driver

My 24kV high voltage "Jacob's Ladder" from DIY flyback transformer driver using 555 timer. Creating an electric arcI've always wanted to create an electric arc but don't know how. Then I come across the theory that air breaks down at about 1MV/m (Mega Volts per meter) (24kV/in). That mean you need 1kV in order to get 1mm arc. So you need a higher voltage. One of the method is to use a flyback transformer that can be found from an old TV or an old CRT PC monitor. It could generate about 10 to 30 kV. Other method is to create a "tesla coil" which is quite complicated. Maybe it will become my next project. Flyback transformer and preparationFlybacks can be found in all types of monitors and screens that use a cathode ray tube (CRT),...

Read more »