Skip to main content

Trio Kenwood KD-1033 turntable main bearing service

  One of my first posts in this blog was regarding the servicing of the Pioneer PL12D turntable, and that has proven to be the most popular by a significant margin. The Pioneer PL12D had its competitors, and probably the most popular alternative was the Trio Kenwood KD-1033 turntable. I use both names (Trio and Kenwood) as the company operated under different names in different markets. In the UK they were Trio, possibly because the brand Kenwood was most famous here for food blenders. 95% of a KD-1033 is similar to  Pioneer PL12D, and servicing them is very much the same process. Both are belt drive , have an AC synchronous motor,  mechanical speed change , a main bearing, sprung top deck and rubber motor mounts. the KD-1033 uses a different type of anti skate mechanism, employing a thread and weight. The plinth is shallower with an internal cross brace. One aspect that is different is the design of the main bearing, and servicing it is a little harder than a PL12D. The ...
2 comments

Fixing an intermittent ViewSonic LCD Computer Monitor VX924 VS10162

I recently decided to dust off an old gaming PC from around 2006 that was in the attic.

I'm interested in folding@home , a way of assisting medical science donating computer time from home , and  wanted to see if I could build a dedicated FAH (Fold at Home) rig using spare hardware we had.  I'm also interested in computational heating i.e better exploiting the waste heat from computer systems . This  will be the subject of another blog shortly, but when I got this PC down and booted it up, I immediately hit an issue with the LCD screen. It kept turning on and off approximately every second , but sometimes staying on for longer. I could see the boot screen, the BIOS and eventually the windows logo, but the screen wouldn't stay on. Very frustrating

I later realised that if I left the monitor on for at least an hour it would stabilize and become usable.

I looked around  on the internet and realised this was probably a problem with the capacitors in the power supply. If you have read my other blog about repairing some M-Audio BX5a speakers , they hit a problem , similar in cause, bulging power supply capacitors.

The monitor is from 2006 and not super high res, but I didn't want to throw it out for the price of a few caps so decided to have a look inside. 




First disconnect the monitor from the power and the PC. I laid it face down on a soft towel on the table and removed 4 screws holding the back panel on. This could then be unclipped gently around the edge.


the electronics on the back of the screen is protected by a metal box section, and again some screws hold this in place. There are also some adhesive foil screening material used to bond protect some of the cables from interference. I teased this back, planning to refix it in place after.


With the metal box screen removed I could see the two neat circuit boards, the left having the power supply functions (Top in the picture), the right the display and logic. Some gold pins and socket linked the two boards, and removing 4 additional screws enabled me to lift the power supply board away from the other board, for closer inspection. It remained tethered by a number of cable assemblies but I was able to invert it to access  the underside of the board.


I could see immediately that two identical power supply capacitors exhibited bulgin at the tops. No electrolyte had leaked , but the silver part at the top of the can was certainly not flat.





In addition a 3rd capacitor, wrapped in some kind of heat shrink, also exhibited the same problem









So I reckoned these might be why the monitor kept switching on and off. I desoldered the 3 caps using my trusty old soldering iron, and a mechanical solder sucker, and found it pretty easy to pull the offending caps down while inverted and  softening the soldering iron to loosen their connection

They came out quite easily. each had a blob of some kind of adhesive next to it, but this crumbled




The caps were two 470uF 25V Radial 105 degrees Centigrade (Max operating temp) and one 330uF 25v Radial 105 degree cap. I ordered replacements from Cricklewood Electronics which came in a few days and cost very little. I like Cricklewood , service is good and they are happy to sell you a single capacitor, no need to order more than I need.




When the replacement caps arrived, I fitted their leads through the holes. I'd taken note of the polarity (the white stripe down one side of the can denotes the negative terminal. However the circuit board also had indications of the polarity where they sat, with a cross hatched marking for a segment of the circle corresponding to the negative terminal. taking photos during the removal is always a good idea.



I resoldered the leads, and cut the excess wire from each. I fitted some heat shrink insulation around the cap that appeared to have additional insulation around it. It looked intentional and original, perhaps to protect it from the inductor next to it (Copper wire coil around a carbon core) 


I then refitted the Power Supply circuit board back connected to the logic board and refitted both the 4 screws that held it in place and then refitted the cover , making sure all the foil screen pieces pressed back.




I fitted the back to the screen, refitted the remaining screws and plugged both the signal and power leads back into the monitor. It immediately stayed on, no flickering and has worked perfectly since, so a correct diagnosis and easy fix. Very pleased to have saved this old monitor for a few pounds worth of caps and a bit of soldering.
Labels:

Comments

Post a Comment

Popular posts from this blog

Restoring a Pioneer PL-12D Turntable

 I got back into vinyl records about 18 months ago, and have collected a few hundred albums, mostly second hand. I have a number of turntables (NAD 5120, Ariston QDeck, Pioneer PL12D ) which I got also second hand. I keep a few, some end up passed onto friends, some that are too far gone are kept for spares. In most cases they have required a little work to get them running again. Last week I was lucky enough to get a Pioneer PL-12D turntable from freecycle. The lady who offered it, said that she in turn had received it from freecycle , and had replaced the belt but couldn't get on with the springiness of it, and had got a modern USB turntable. I have previously worked on one of these decks, and know what she means about the suspension system used. While this blog is specifically about this particular model of deck, many of the concepts are similar to others from this vintage. Many Japanese belt drive decks throughout the  1970's shared very similar construction, so this m...
284 comments
Read more

Bracing IKEA EXPEDIT or KALLAX cabinets for greater rigidity when used with a turntable

The inevitable problem, too many records. Turntable and amplifier on top Like many record collectors around the world, I have a number of IKEA cube cabinets from both their EXPEDIT (older) and KALLAX (newer) ranges. These are easy to make, cheap to buy and perfect for record storage. The system comes flat packed and uses bolts and dowels to hold the system together. If you follow the instructions  the system is strong and should not collapse. You can augment the joints with PVA wood glue for extra strength. My turntable sits on top of an EXPEDIT 2x4 cabinet, laid along the long side, with some felt feet to support it from the floor, and you can use KALLAX in the same way. It's been great but has two problems I wanted to address : 1) Because the system has no back panel, the records  can be pushed too far back. 2) While the structure is strong and fairly rigid, there was some lateral movement. With heavy equipment on top, I found that if I nudged or knocked either top side, thi...
3 comments
Read more

Replacing MR16 Halogen bulbs with LED equivalents

If you have read my other blogs about GU10 mains voltage halogen lighting, you will know that I have mostly replaced these bulbs with LED equivalents. they cost more, but last longer, are cooler and use a fraction of the energy. a halogen bulb is typically either 35 or 50 watts. most LED bulbs are 3 watts. While the bulbs in my house are predominantly GU10 mains halogens, I do have a couple of MR16 bulbs. These are a different type of halogen that operate from a 12volt supply. I should mention at this point that I don't have any dimmer switches in my house. Now some mains voltage GU10 LED bulbs are dimable (always check first). MR16 bulbs have two pin connectors rather than the lugs found on GU10 bulbs. GU10's use a push and twist method of connecting to the socket. the MR16 simply push in place with metal clips also gripping the edge of the bin base. They use a separate power supply , either a transformer (old type ) or a switch mode power supply(newer) to convert 250v ...
106 comments
Read more