My well used electric trimmer suddenly had an issue with it spinning slowly and the motor noise changing to a whirring sound. I had recently replaced a worn out spool cap (bought a 2-pack with a spare).
Taking it apart was a bit tricky. You need to remove the lower guard first. It is held in place by one screw and a wide flat locking tab which needs to be pryed free with a flat screwdriver. There are 4 more screws on the top of the guard that hold an air duct from the motor.
With the guard removed, then it’s just 12 phillips screws holding the two halves together. A spring may pop out which comes from the opposite side of the release button that extends the handle.
I noticed quite a bit of gunk in the gear assembly and also noticed the inner teeth of the plastic gear were worn. The whirring I was hearing was the gear spinning on it’s own and not catching the inner teeth. The air intake was also pretty clogged with grass so it would have been a good idea to clean it regularly to provide good air flow to cool the motor.
Probably time to buy a new trimmer and maybe upgrade to a cordless one.
1 screw and locking tab
Gear on motor drives outside plastic gear with worn teeth
This TV had no standby voltage. Power supply board is RDENCA354WJQZ (DPS-208BPA). A badcaps post pointed to the potential of IC7905 TNY264PN being bad. This post indicates R7918 may need replacement. On my board, the IC blew up and broke on top but R7918 measured 2.4ohm which was ok.
I ordered a replacement IC on Ebay, installed it, but still got no power. Further research indicated R7914 may be blown which is a 2.2 ohm fusible resistor located under the bottom shield. I measured it, and it was open. Shopjimmy sells a repair kit for a similar power supply RDENCA336WJQZ (DPS-286AP) with a replacement IC7905, D7908, R7914 and R7918.
I ordered a replacement for R7914 (2.2 ohm, 1/2W fusible resistor Digikey #PPC2.2BCT-ND and D7908 (1N5383 Digikey #1N5383BRLGOSCT-ND). D7908 tested ok but I added it to the order since I had to pay shipping anyway. After installing the new resistor, the TV powered up.
I would also recommend updating the firmware. You can download the file from here. I was unable to download the instructions. You need to unzip and copy the .bin file onto a FAT USB flash drive (not FAT32) and plug it into the service USB port. There is a software update option in the setup menu. It should find it, and ask you if you want to proceed.
I have a problem where I needed dual USB jacks for charging up to two tablets. The area I need power doesn’t have an electrical outlet so I have run a two prong extension cord. You can buy electrical outlets these days with built in USB ports but this wasn’t an option in my situation.
There are a lot of dual port chargers on ebay but you do have to worry since most cheap chargers do not have UL safety certification. You need to pay more for a name brand product. You don’t want to start a fire to save a few bucks. Chargers are not created equal though they may look the same on the outside.
To charge the larger batteries of tablets, you need one that outputs 2-2.4A which is more that a standard PC USB port. Checking specifications, sometimes it’s not clear if on dual port chargers, both ports output that much current.
I was able to find the Blitzwolf BW-S3 at Banggood shipped from China decently priced. Their website indicates their products are safety certified though there is a chance of getting a counterfeit item. The charger arrived fairly quickly and is working well.
I had the micro usb jack on my android Asus ME301T tablet wear out and I replaced the connector unsuccessfully with the part ordered on ebay. While removing the motherboard, I broke the locking tab on one ribbon connector (yanked it instead of lifting up) and the new connector was flaky since I couldn’t get enough heat to solder down the ground tabs with my old soldering iron.
I eventually ended up finding a new motherboard on ebay and replaced it. Ever since, I have been worried about the micro usb breaking again. There is a lot of wear on the connector since it needs to plugged in at least twice a day or more. I have been using an extension cable and leaving the micro usb cable plugged in but was worried there could be more damage if it is dropped due to the weight of the tablet and stress on the small connector.
My fears became real when I dropped the tablet with the connector plugged in and the connection became flakey. Searching ebay for cables, I stumbled on magnetic adapters. They appear to be knockoffs of a kickstarter project, Znaps but there are other suppliers including Wsken and Volador which have good reviews. On Amazon.ca, I found a Onebook (probably a knockoff) cable with two plugs for $10 CAD shipped.
I decide to order a new tablet and was able to find the Asus Z300M on Amazon.com for $130 during Amazon Prime Days. I ordered a silicon case and a Wsken Mini2 magnetic cable to go along with it since the Onebook cable may take months to arrive. The cable included a plastic tool to pry out the adapter and a small velcro cable strap.
So far the Wsken cable seems pretty good. The plug is uni-directional and will catch about a centimeter away. No more fussing trying to align the plug and determine if it is the right direction. If the plug is reversed, the magnets will cause the plug to repel. There is also a small LED on the plug to indicate it is getting power. Retention is very good. This adapter should prevent wear on the plug and break away if the tablet is dropped when plugged in.
Update – After 5 months, the plug for the Wsken Mini 2 broke. I had the Onebook cable sitting around so switched to it.
The Onebook cable is a bit thinner and has a dual colour LED that changes from green to blue when charging. It is also completely reversible.
Update 2 – The onebook plug broke as well. Luckily I have a spare but it doesn’t seem like this model is carried by the Amazon seller anymore. I have a 3-pack of Netdot cables in my Amazon cart as a backup if this one breaks. Though it may seem fun playing with the plug magnetically snapping it to the cable, I am now gently letting them connect to get more longevity from the plug.
Update 3 (Apr 2021) – I had ordered a 3-pack on Gen2 Netdot cables on Amazon in 2018 and all three plugs have broken. The first one lasted a few years and the last one broke when my tablet fell charging and the magnet didn’t disconnect. I contacted Netdot and they are in Gen10 for their cables and didn’t have plugs for Gen 2 anymore. I found inexpensive Keysion cables on Aliexpress and ordered 2 cables ($1.99 each) and 6 plugs ($0.69) which should be good for a few years hopefully.
This Philips TV would turn on and then the backlight would promptly shut off after displaying the logo. Inspecting the boards, all capacitors looked good and voltages were stable. The TV was not shutting down and going into protection mode.
Advice on badcaps indicated the possibility of bad transformers on the inverter board. I measured the resistance of the secondary windings and got 593 & 556 ohm for one transformer and 589 & 589 for the second one.
I ordered a replacement board LJ97-03241B on ebay and the seller sent me 3 boards. He indicated he just wanted to get rid of them. Before installing, I measured the secondary windings and got around 562 ohms on both winding of both transformers. With the new board in place, the TV powered up and the backlights stayed on.
This TV had no power at all. No LED indicator and no standby voltage.
Lots of threads on badcaps indicated problems with transistors shorting on the X-Main board which causes the power supply to shut down. Symptoms would be repeated clicking of the relay and a flashing LED. Older versions of this TV had a firmware problem which may have contributed to this failure.
My TV didn’t make it to this step with the lack of standby voltage. There is a fast track troubleshooting guide and the first step is to check for the 5V standby voltage.
The power supply board (part #BN44-00442A) is suspect but there were no blown caps and the fuse was ok. I had a power supply board for a 51″ TV of the same series (part#BN44-00443A) and the PCB itself was identical. I installed it in and the TV powered up.
I’d like to debug the old, non-working board but without a schematic, it is a bit difficult.
This TV had backlight and sound but no picture. A badcaps thread indicated a common problem was a blown fuse on the Tcon board. On my TV, I found 3 bulged 1000uF/25V capacitors on the power supply and the blown fuse. The Tcon was difficult to access because there was a shield and part of the frame blocking it. I had to peel back the foil tape to expose and unlock the ribbon cables and unscrew part of the frame so I could slide the Tcon board out. The P marking on the 0603 fuse indicated it was 3A and I replaced it with a 1206 3A fuse from a scrapped Tcon board. With the parts replaced, the TV powered up with no issues.
This TV had no power. Opening up and inspecting the power board found two bulged capacitors: Teapo brand with values 2200uF/10V which I replaced with 2200uF/16V. After replacement, the TV powered up with no problems though the side power button was a little flakey.
This Toshiba TV would turn on but there would be no picture or no backlight. Probing the power supply outputs, I detected no 30V, no 20V and no 24V (powering the inverters for the backlights) but the rest of the voltages were present. I was able to find a schematic online and it pointed to a regulator STR-Z4579 which provides these voltages. I ordered the part from ebay and when I replaced it, I still got the same results as before.
I checked every diode, resistor and capacitor in the circuit but didn’t find any bad components. I then suspected the regulator was shutting down due to a fault. I unplugged the 24V connectors going to the inverter boards and the 30V and 24V were now present. The 20V appeared to be unused from the schematic.
I measured the resistance of the 24V input on the master and slave inverter boards and found a short on the master board. Checking the four transistors, I found shorts on two of them. I ordered the replacement FDD8447L transistors on Digikey but when I searched on ebay afterwards, I found repair kits consisting of four transistors and the IC BD9897FS. If the transistors don’t fix the problem, I will need to order the IC as well. Searching the board part number 6632L-0450A (PPW-EE42VT-M) on ebay also turned up a repair kit. Looks like this failure also appears on Toshiba model 42HL67.
Update: Replacing the two shorted transistors and putting the board back in caused them to short again. I have ordered the repair kit with the controller IC.
Update 2: Replacing the controller IC didn’t help though the 24V was stable and there is an LED on the inverter board that flashed when powered up. I suspected bad soldering on my part.
Searching replacement boards, I found an Aliexpress listing indicating the following boards were all compatible.
Other model numbers include LN40A550P3F and LN40A550P3FXZC.
Opening the back encountered 3 bulged caps on the power supply. I replaced 3 additional caps for good measure.
CM804, CM806 – 1000uF/25V
CM809, CM812 – 100uF/10V
CM810 – 470uF/10V
CM808 – 220uF/25V
CM813 – 47uF/50V not replaced, not bulged, didn’t have this value in stock
