Wednesday, August 30, 2017

Chamberlain/Liftmaster/Sears Garage door opener range issue

Rental apartment I’m at has a garage door opener that’s been working well up till recently, it would open with the remote but not close.

I’ve been living with that (and jumping across the sensors below that detect when something is in the way) until yesterday it wouldn’t reliably open unless I was up against the garage door (boy was I worried). I was also worried about interference from LED lightbulbs that could potentially be affecting it’s range, turning off all lights resulted in no change so it wasn’t that.

I tried re-pairing (reprogamming) the remotes to my garage door opener (I have 2) and unless I put the remotes up against the opener it wouldn’t pair properly.

Apartment techs came over to take a look and they decided to change out the entire garage door opener (current unit is from 2006 so it’s 11 years old), however procurement will take a while and I’ll be stuck having to use the wall switch (that still works) or the manual pull.

Decided to tear into the logic board to see what’s going on and if I can fix it.

WhatsApp Image 2017-08-29 at 10.36.10 AM (2)

That’s the plastic back that holds the logic board, removal is easy (3 sets of wires for the wall switch and sensor) and 4 screws. Mine is a 41A4252-7G, I suppose quite a few different models of garage door openers from the same manufacturer will be similar. Disconnect one connector and it should be free to move to your workbence, a few more screws hold the main PCB to the plastic back.

WhatsApp Image 2017-08-29 at 10.36.10 AM (1)

Board out, no broken joints like I’ve read on some other places.

Decided to remove the main filter capacitor on the input of the 5V regulator (I’ve read elsewhere where someone had a similar issue that injected noise into the RF section and killed reception).

WhatsApp Image 2017-08-29 at 10.36.11 AM

o.O. More than 25Ohms ESR? That’s definetly bad, my DMM had a capacitance measurement that indicated that it’s 220uF (it’s marked 330uF), doesnt seem that bad but ESR was indicative of a failed unit.

WhatsApp Image 2017-08-29 at 10.36.11 AM (1)

A trip to Tanner Electronics nearby got me 5 Nichicon 330uF 35V capacitors for $1.25. Their ESR measures 0Ohms.

WhatsApp Image 2017-08-29 at 10.36.10 AM (3)

Here’s the location of the capacitor.

WhatsApp Image 2017-08-29 at 10.36.10 AM

Board overview.

After soldering in the new capacitor and hooking it all back up. My garage door opener works good again. Yay!

Monday, February 8, 2016

Gameboy pocket LCD backlight + bivert mod + LCD repair Part 1

This project started with me finding my old Gameboy pocket. It was still working, but the LCD had developed a dark spot in the middle.


Kind of like this one, the picture is not of my gameboy. Booting up games with it results in this.


Looking around for solutions to this issue, it seems like

1. Gameboy pocket replacement LCDs are hard to come by.

2. You could do some really cool stuff now with backlights and biverting (more on that in a moment).

I went ahead and ordered a backlight module off nonfinite electronics (which should come with a spare polarizer).

My thinking was that there was something wrong with the reflective layer or polarizer and that since I would be getting rid of those layers during the backlight mod, all should be good.

I pulled the LCD module out of my gameboy pocket and set to work.


Look at the discoloration on the rear polarizer + reflective layer.

Putting in the backlight module, I realized that the issue was not just contained to the rear layers, the front polarizer on the LCD had also suffered damage (I think the glue has breakon down in the middle spot).

I tried removing the front polarizer, which was fairly difficult. Not only did the front polarizer pull off, another semi-shiny layer of the LCD also peeled in some places as well, figuring I had nothing to loose, I removed everything and stuck on the replacement polarizer.

Eventually after a few hours of mucking around, the LCD did work, somewhat, in the process of doing all of these and trying to remove all residues, I had to use acetone to clean up the LCD, I suspect some of that seeped under the LCD connectors and compromised the connection. I was now missing some horizontal lines.

Next I tried the age old tested method of using a soldering iron to try and re-bond the connections, the Gameboy pocket has a slightly different kind of ribbon cable though.


Even with a fast swiping motion, the whiteish ribbon cable was over-melting and that was the end of my experiment of fixing that particular LCD.


Part 2 will follow after I find another Gameboy pocket and pull some parts off it to fix my existing console.

Friday, January 1, 2016

Blogger returned the following error "NotFound: Not Found"

Using Windows Live Writer and find that you can’t publish your blog entries because of this error?

You’ll get a popup just like the below and then a login prompt will come up, nut even the right password doesn’t work.


According to here:!topic/blogger/lw_sNsyySKI

Essentially Google has upgraded their authentication systems and because Windows Live Writer wasn’t being maintained there’s nothing they could do about it.

However Microsoft has made Windows Live Writer open source and the team has updated it to work.

Just download the new application here:

It still looks and feels exactly like what Window Live writer was like so I’m not complaining.

Vitamix blender motor repair

Windings on motor rotor were damaged, I think the chaffing on the insulation led to a breakthrough and subsequent failure.

I had to completely unwind the rotor and rewind it with the same diameter enameled wire (the damage was on one of the innermost windings). Here we have a 220V mains, so the motor might be slightly different from the more common 110V US units.

Blender is pretty old, Vitamix wants a serious chunk of $$$ for a replacement motor. Admittedly I had to spend quite a bit of my free time to get this fixed, but it really only cost me $40 in raw materials.


Breakdown of the vitamix blender. Should've taken more photos.


What a new motor will look like, inside is essentially an open frame universal motor.


The rotor out of the motor and me unwinding motor. I had to remove the center insulation pieces all around and document how each winding was interconnected.


Another shot of the old windings.


I drew a little diagram to sort out what goes where. The motor had 22 commutator segments and the same number of slots for the wires to wind around. Each winding was 22 turns of enameled wire.


The motor partially wound, I elected to solder every end onto the commutator for a more reliable electrical connection.


Cleaning the completed motor to prepare for application of red enamel.


Red enamel applied on one side.


The original bearings on the rotor were made by NMB, 608SS. SKF does the 608RS that's also a rubber sealed bearing.


After the enamel has cured, this is what the rotor looks like.


Replacement bearings side by side with the existing ones.


I had to grind and cut off parts of the bearing to remove it piece by piece to get them in. There was insufficient clearance to pull them off.


Bearing inner race still left on shaft, for this challenging location I ground 2 flats on the inner race and used a vice to apply pressure until the inner race cracked and separated from the shaft. Usually this works quite well because the races are super hard.


Replacement bearing now on.


Motor assembled together, sans the 2 brushes.


Motor assembled into the blender.


The ass end of the motor/blender. A plastic impeller that moves air for cooling the motor goes here.


The blender finally together. It was tested out and it really kills ice cubes (we tried blending a bunch of ice).

On a side note. Happy new year everybody wlEmoticon-smile[2] 2015 went by really fast for me, here’s to 2016.

Update: 17th April 2016

The Mechanic has kindly went ahead and did up a professional looking diagram of how the motor is wound up. I hope the motors he has get fixed.


Note that the commutator is not shown in the top down view, only the windings are.

Sunday, May 17, 2015

Philips 40PFL5507H TV firmware restore

Came back home one day to an hourglass on the display of my TV, instead of the usual power up sequence.


It just sat there for a couple of seconds before going to a blank screen. Reading online I found that it could be due to a corrupted firmware.

From the Philips website I downloaded a copy of the latest firmware and put it on a USB thumb-drive.


However I was unable to get it to start the firmware installation process, regardless of the different methods that the help file included within the firmware download suggested.

I then looked around more and found a copy of the service manual for my TV here.

In it, there was a method to invoke an alternate or backup software/firmware function, to be used in the event the default upgrade application does not start (sounds like me).

1. Disconnect TV from power.

2. Hold the DOWN cursor while reconnecting TV to mains.

3. Backup software application should start.

Following these steps I managed to restore the firmware on my TV (I had to go through channel setup as well, since those were lost)



With that done, I proceeded to enjoy some Discovery Channel. Smile

Tuesday, February 24, 2015

Yashica GT Pad of death + Rangefinder cleaning + Light seals

Picked up a Yashica GT for cheap (under USD$15) locally which was known to have the POD (pad of death) issue, basically a small foam piece inside goes crumbly and then the shutter will start going crazy.


First steps are to disassemble the camera until you can see where the pad is.


Here I’ve removed the advance lever.


I planned to do this over the course of a few days, so bagging and labeling the parts was important, putting it all together and then finding out you have some stuff still on the bench is not cool (been there done that).


ASA dial comes off next.


Below that is a little washer which is basically what keeps the stationary part of the dial in place.




Now we have the film rewind knob


I wrapped tape around a screwdriver for me to use as a leer against the knob.




There’s a small washer right under there.


Below that there’s yet another washer that I guess keeps light and dust out of the innards.


After removing 3 screws around the top cover,gently pop it off, there’s a wire still in there for the flash, so be careful.


I chose to de-solder this wire so I wouldn’t have to be mindful of it while working on the camera.


Residing within the top cover is the battery test button, I took it out before moving the top cover too much (prevents it from getting lost).


Here we can see the problem, right there (just above CA in Yashica) is the deteriorated pad.

To get at it, you’d have to separate the lower mechanism from the upper. I did this by temporarily re-installing the advance lever, advancing and then using an allen key depress the lower mechanism.


With that out of the way now, we can get at the pad, there are other methods that involve disassembling more of the camera so you get better access, however that involves removing part of the leatherette on the front of the camera, I didn’t want to risk damaging that so I chose to do it ‘surgically’.


Here I’ve straightened out a bobby pin (from SWMBO) and put a small bend on the end to scrape out the remains, it helps if you can hold the camera upside down so the stuff falls out. Initially I wanted to use some of that black foam as the replacement material, but it was too soft.



For a far sturdier material I opted to use a small piece of eraser, the critical dimensions are 5mm x 4mm x 2mm.

Using the bent bobby pin and working upside down I leveraged the replacement piece into place.



Here it is back into place.

My camera had a sorta haze all over the rangefinder window, cleaning the glass and lenses that were reachable still didn’t quite cut it, contrast was really low on the RF patch, so I bit the bullet and attempted to clean the rangefinder innards.


This copper plate is all that exists between the the innards and us. Using a utility knife I slowly leveraged it out. A few drops of cement are all that holds it on, it is quite thin and feels fragile though.


Initially I cleaned everything in here with a Q-tip soaked in lens cleaner except for the beam splitting element (the gold coated piece), as I’ve heard that the coating can be extremely fragile, however the RF image was still not very clear because of the build up on there, so I went ahead and cleaned it anyways using no pressure at all (a damp Q-tip and then just dragged it over) the coating didn’t appear to be damaged, be very careful though, I’m not sure how much it takes to get it off.

I also replaced the light seals on my camera, they were starting to fall out in some places.




Didn’t take too many pictures of this process but it’s really simple. I taped up the rear with a piece of paper and some tape to prevent anything from getting into the rear lens element area. Then using alcohol and a plastic pick (it was a dental pick thingy) I removed as much of the old seals as possible.

New light seals were cut out and re-glued back into place.

I’ve so far shot a roll of Ilford HP5+ through this camera and the results are really good, the metering is easy to use (either the shutter speed is too slow or fast, but you don’t know by how much) and the lens is fantastically sharp. Focus is spot on, on my camera at least, a pretty good deal for what I paid for this.