Sunday, April 24, 2016

Laserdisc player repair...and repair some more...

I have a bit of  nostalgia for the era of my youth...or even a decade ago...

I still listen to my vinyl...I have a pile of cassette tapes, and a tape deck to play them...I have a nice VCR...but I only use it to transfer from videotape to digital...

I have this memory from the mid 80's when I was at a record/video store and they had a laserdisc player up front, connected to a large TV and playing U2's Under a Blood Red Sky concert from Red Rocks...note that I said Laserdisc, not VHS, not DVD (didn't exist yet) (BTW that concert wasn't released on DVD until a couple of years ago).

I always wanted a LD player after that point, but of course they were very expensive, and the LD themselves were expensive and hard to find, depending on where you lived.

For the last year or so I have been researching LD players etc...Finally settled down on a few models, and finally picked on up...it wasn't on my list of players to get, but it had a large collection of LDs with it that I wanted.

Well...the shipper did a piss poor job of packing and it arrived smashed/squished in the front.








Well you can imagine that I was as crushed as the player...the seller gave me a partial refund, and I kept the disks.

So I have this busted LD player for free...now what?...I guess I will try to fix it...

Let me say that I got very lucky...yes the front panel is smashed, and the circuit board corner near the jog/shuttle is broken...but luckily it is not necessary for operation.

I won't waste time describing the mess...I didn't take any pictures because I didn't think I would have any luck.

Let me just say that I had to bend a lot of the steel frame back to somewhat shape...I had a straightedge I checked with...I took the entire top assembly apart, I took the optical system out and straighened some sheetmetal there...I had to spend a lot of time adjusting how the optical system flips from side A to side B...and finally about 2 hours trying to get the tray back in with the entire loading system back in sync.

Well all that worked, it correctly played disks and flipped to the B side.  I watched about an hour of Star Wars IV with all the glorious film artifacts, and where Han shoots first...no CGI in sight.

...then near the end of the second side it died...

It shut completely down and I quickly pulled the plug...I was afraid that more magic smoke would escape.

I will admit that when I ran it, there was an eletronic smell...so I figured something would give out eventually...

And you know with the older electronics that you can expect the the capacitors will have been of minimal quality and will eventually dry out and fail.

Well yup it happened...



That cap I am holding in my hand is just the aluminum cap...the fuzzy mess at the middle of the upper picture is what is left of the cap...just above it is it's matching cap.


So I just ordered some caps from Digikey, and will replace all on this board...15 caps total, about $15...Hopefully nothing else was damaged in the process...BTW the cap lid was near the center spindle...about 6" away from where it blew up.

...stay tuned...



Friday, March 18, 2016

Here is a big diversion...Undercounter Ice Maker Repair. Kenmore Elite 106.89583705

I follow a few really smart folks who do a great job at describing how they troubleshoot, and then repair.

https://www.eevblog.com/  his YouTube channel.

The Signal Path Blog


Those are the two I reference most...but there are another handful of folks that do a great job of documenting a problem, their investigation, and the solution...or sometimes no solution.

Because of those inputs I have repaired a handful of wall-wart power supplies, 3 monitors, 5 computers...and now an Undercounter Ice Maker. (similar to the pic below)



I know...what the heck does an ice maker have to do with Electronics?   ...just wait.


SO the house we bought a couple of years ago came with a few extras...including a Kenmore Elite Undercounter Ice Maker  Model 106.89583705 manufactured in 2011.11.

First, let me tell you that after decades of using funny smelling refrigerator ice...a stand alone ice maker makes terrific smelling and tasting ice...so I wouldn't have thought of buying one myself, but now after using one, I cannot go back to fridge ice.


Quick background.  Fairly simple device.  Main ice storage area maintains a cool temp, a water tray within this area is filled with water.  A plate is cooled until frost forms on it, water from the water tray is gently poured over the cooled plate until ice of a certain thickness is formed...at a certain point the cooled tray is warmed, the ice slides off and onto a grid of warm wires...the wires slowly cut through the ice (combination of gravity and slight heat)..the ice falls into the main bin...and the cycle starts over.

So there are some main parts...the refrigeration unit...cools the main box, and the plate.   The water tray that need to be filled to a certain level.  The pump that pushes the water gently over the cooled plate.  The pump that empties the excess water from the water tray. and the grid that cuts the ice...and of course a way to measure temps.

When we first moved in, the ice maker was making a ridiculous amount of ice...you open the door and ice falls out.   After a tiny bit of research I learned the temp probe in the main box was bad...easy plug and play fix.

After about  a year of living there, the unit stopped making ice...sometime in February (We live in the south, ice is a thing year round).   After a lot of time googling, I found a couple of service manuals (for older models) and a bunch of forum questions, and few answers.

The service manual I used... a KitchenAid 2007 15" and 18" Automatic Ice Maker pdf, KAR-19.

This web page describes how do do the self test.

Guess what...all the machines are identical.   I actually used whirlpool replacement parts.  (I have a Kenmore machine)

Ok,on  to the repair.

I pulled some of the internal panels off to get a better view of the machine, and what it was doing...the first thing I noticed was the water level sensor middle wire was hanging loose...I am not a refrigeration engineer...but I think that is a possible problem.






I assume the plugs are standard parts...so I search Digikey and find a plug that looks similar, and has similar measurements...so I buy a male and female and 6 of the male and female pins (I figured I would have problems...I was right)


 I also had to get a crimper for those pins...I had one for smaller servo pins...but not this size.


Long story short...I  had to pull the unit out from the cabinet, remove an access panel on the back, unplug a molex connector, and shove the wireing harness through into the box to get enough access to fix the other end.  (the water sensor was removeable, but the matching harness was in the back of the unit.


When I first investigated I saw the middle pin on the water sensor was corroded and out...I assumed the other end of the connector was just as bad...I was right.

So all that is fixed, put it partially back together, do a test...and still it won't circulate water over the cooling plate...so it still won't make ice...ok, so maybe the "recirculation pump" is also defective.

They do go bad, so I bought a replacement recirculation pump...and a replacement water sensor while I was at it (my fix didn't test correctly).

Again, partially back together, do a test, and still won't circulate the water over the plate.

The only thing left to replace is the $270 control board...



Looking at some pictures of the control board, I see that mostly it is relays...I follow the schematic from the service manual...and all the wires correctly end at the control board.   (my Kenmore icemaker has Whirlpool #2304129 rev b)

My control board is identical to that reference picture except for the relay make and model.  For reference, the first pin on the right of the big black 6-pin socket is pin #6...that pin runs the recirculating pump. The next pin over (#5) is power, and the pin left of that (#4) runs the water tray drain pump.   The broken relay is the third one over from the right edge...one of the two under the sticker. (the other one under the sticker is for the drain pump).  I think the two at the right side are for the heating grid and the lamp...the big relay below the two with the sticker I think is for the A/C system.


I figure I have nothing to lose by replacing a relay on that control board

I look at a close up of a replacement board and get relay OMRON G5LE-1R4DC9



I pull my board after the replacements arrive (I got spares) and see this model.



Digikey shows this as a discontinued part, but the specs were almost identical to the OMRON that comes on the replacement board.

There is a conformal coating on the PCB, but a bit of heat gun and some scraping removed it...also before I desoldered the old relay, I added some solder to the pins.

I had a 9vdc power supply to test the relays...I used the continuity 'tone' on the multimeter with the probes clipped to the switch pins...when I applied power to the new relay I heard the successful tone....so then I tested the one I desoldered...if it failed the test, then that means my guess was correct....so fingers crossed that it would fail...the relay did click, but the contact did not close...whew!

The fix was successful!  I put some silicone sealer over the resoldered pins...and reassembled the machine...after about 30 minutes to cool down, it started to make ice again.


Grand total.

I had to fix the pins...a few bucks for parts, and $12 for the crimper
I replaced the pump, but didn't need to (so now I have a spare)  $60
I couldn't successfully fix the pins on the water sensor so I replaced it  $30.

and to fix the control board... a $1.50 relay.

I posted all this, because I used to think that things like this (the control board) were not repairable...but the reality is, many parts are replaceable if you do some research and have the tools...

For me, the single most important tool I have acquired over the last few years is my desoldering unit.


Wednesday, January 27, 2016

More on the MD-380, Experimental Firmware, and DMR setups.

So yesterday I got the radio and although the firmware update was straight forward...and using the radio programming software was somewhat straight forward...I still had no idea what to put into the radio programming software.

From when I wrote the last post till around noon today I was researching and editing and uploading to the MD380.

BTW, the Experimental Firmware lets you see (and hear) QSOs even if you are not listening on that network...So I made a contact on the Statewide net, and we figured out we could use the 'metro' net, he switched over before I did, and I could see his ID, the net he was on, and here him check into the new net while I was still on the statewide one...I can see some issues on a busy net, so I need to figure out how to toggle off that 'feature'.

I would say the single most important thing to do to program your radio...if you have no clue about DMR (like me) is find a "Codeplug" for your radio and your area (although if none exist for your area...any one will help you understand what goes where and why).


So on the TYT-TYTERA MD-380 USERS GROUP  in the Files section you will see a folder called "Country Codeplugs" download the appropriate ".rdt" file and use that as a starting point for programming your radio.

The one for my area had a bunch of the local repeaters...but not the one closest to me...so I had to edit the file.

While I was sifting through the internet I came upon this page which has a lot of links on the MD380 organized.

But it was on Youtube where I found this channel and specifically this video on how to use the programming software.

So using that info, and the specific Repeater info from here...I was able to program my radio.



The quick summary on how DMR works for dummies is...each repeater has a handful of networks they are connected to...or they will allow you to connect to...more like echolink than linked repeaters.

The following is not a step by step of how to edit and program the channels...I think the video does a better job, but between the "rdt" file you downloaded, the video and these notes, hopefully you can figure it all out.

For example, if you pull up the repeater info for Houghton MI in the U.P. you will see the Rx freq, and the Tx shift (you have to do math an either add or subtract a few MHz)




The Repeater has a Color Code of 1...
It shows Time Slots...the MD380 software calls them "Repeater Slot"

That info goes into the individual channel you are trying to program.  For this example of Houghton MI, if you wanted all the channels they had available...you would need to make 7 channels.



All the Group Call stuff goes here...under "Digital Contacts" .   That is where the "Contact Name" from the channel (above pic) comes from.


Now, the screen shot has some different ones than the Houghton repeater has...so just add them...


The only one I don't understand is the "Digital RX Group Lists"...but once you have populated the "Digital Contacts" (pic above) you will see them and can move them over...


I hope those screen shots help a little bit...

I had a nice conversation this afternoon, great sounding radio, pretty good range from inside my car.