I think we need to go back down the rabbit hole. I just got done with rebuilding a 930 I got off ebay for junk. Lord have mercy what a complicated nightmare. Digital board drove me crazy. Nothing worked on this monster. No display I tweaked L77 on the signal board to get it back on . That was the easiest part. Had a low 5 volt line bad caps and resistors behind the fan. It goes on and on....but you know it's really a super rig and I find myself getting attached to the ones I fix. Thank you Buddy for sharing your knoledge on these nightmares. 73

Did fix my TS940 with a pll unlocked by removing the wax! Now it is working well for 30-40 min and then suddenly loosing its rx audio, crackles,... then recovers. So probably a bad connection or soldering somewhere... But these sporadic issue are really hard to grasp! Thanks again for your inspiring videos!

After living with one of these for almost 2 years now, it seems to me that the key to resolving issues is knowing what does what. Mine had the dots below 2 MHz and the display goes berserk after about an hour. I started with the power supplies and backup batteries. Problems here will prevent everything from working properly. Adjusting L-24 on the PLL board one turn counterclockwise took care of the dots. I went through the board with a soldering iron and verified proper operation. What's left, acting possessed after an hour or so, comes down to the Digital A board, I believe. I have had everything from total loss of display after self-initiated auto tuner operation to the receiver continuing to function with no display or a locked display. Back in the day it was easy to fix 940s by module substitution, but finding a good anything for these is a crap shoot at best. The main problem is that the 940 is a really great radio when they work right.

You have to be one hell of a detective to isolate the problem!!👍👍😎🇨🇱

Your explanation of the problems is clear and understandable! Great work! (PD0JGR) Holland.

Buddy Will be waiting for part 2 You are my Kenwood go to guy Thank You Will watch whatever you do

Thanks very much for the time and effort that you put into this channel. I've learned a lot just after watching two or three. Take care, Bob T.

Nice to watch a pro work Buddy! I got my venerable TS-940S new in 1986 and less a fix by Clif at AVVid and three sets of backup battery changes the rig has been operational. I learned long ago to keep detailed maintenance and mod notes on my gear (I'm kinda, well maybe a lot, OCD) and if I sell something to another ham the notes go along to give them the "history" as I hate second guessing someone else's work too! I'm sure you checked the batteries but just in case...can't wait for part 2! 73 - Dino KL0S

Hope you manage to find the issue there, as you say it's definitely a rabbit hole. Looking forward to part 2. Cheers John

Enjoyed the video, Buddy. I am now waiting for Part 2, 3, etc...Lol! Those 930's and 940's can be a bugger! I'll keep an eye out for part 2. 73...Dan

Your repair videos are useful and good ! Did you ever do a part 2 about the TS-940 display problem?

Your repair videos are fantastic! Did you ever do a part 2 about the TS-940 display problem?

very interesting...we will be waiting for part 2

Good job so far.

Hi Buddy, great work so far. If the mods doesn't work, you must check all LO's individually. It is important to know which LO is freaking out and brings the PLL in unlock condition. Is the master ref available?? The caps in the charge pump are also always suspect.. 73

part 2 ? did you ever finish the radio?

I'll be waiting for it. 73 to you!!

by the way great job on showing the problems

I suppose after heavy use for several years the thermal cycle of the PLL board causes cracks?

Part of the problem is when they were designed and built. Like the short lived 930, the 940 was a first generation microprocessor controlled design that has fallen prey to time. When I searched for IC21 on the Digital A board I was surprised to find it in pinball machine repair depots. This device provides a positive reset of the primary CPU and the radio will not operate if bypassed. After recent work my 940 will operate normally for 65 minutes, then the display and buttons stop working but the radio will continue working.

como ficou a finalização desse rádio tenho um do meu uso que esta com o mesmo defeito já quebrei cabeça mas vai ter que trocar a unit pll ok

the only reason I looking forward to a part 2 is I got a 940 it has about the same issue that you are having I got the wax of the PLL now just need to put it back in and test some of the voltages

Very good .. a waiting for part 2. Best Regards Jose M CE 3 LQH

What is the serial number of this radio? Looking forward to Part 2!!!! You might want to include more detail on how you disassembled the radio to show what is involved. What method are you using to clean the connectors?

Золотые руки!

Mine has low modulation on AM. Im.told I sound off frequency. SSB sounds great. Any ideas?

did you ever make part 2 of this ?

This same problem have, PLL board and uPC board checked and still nothing. EEPROM on uPC boardhas lost program?

How about fixing the radio and pt2 have the same problem here and cant seem to find the issue

I had the dots a few years back on mine. Re soldered connections on the PLL board fixed it and still working. The boards were layered in there so took a little effort to get to it.

Still have You got this Kenwood?

You got the patience of Job man. I never owned a new radio,or one that new, I got a sweet IC 751A. and it was 2nd hand,,, but I thought Kwood did better work than that. I have found it best to remove as much cold solder as possible , then reflow with silver or gold solder. Can you get a known good radio to look at and get back to Start? Or buy another and use this one for parts?

My dear sir I cannot thank you enough for such a clarifying informative video! I have exactly the same issues on my TS940SAT and am totally aware of the many problems that can develop over time. But, you actually gave me a direct view 'down the rabbit hole' to the PLL unit as I too have the same problem. Once the radio warms up comes the display but you can be half way through a qso and down it goes again, so frustrating. You hit it right on the head, we don't know what the previous guys have done!! So I will be now following in your footsteps to my PLL unit. Did you leave the plug 5 disconnected after the frequency displayed? Also I get the full output most times, but others it will intermittently shut down, 115 watts out one minute then no tx the next, carrier board likely culprit do you think? I succesfully repaired my TS430S by following a youtube repair video and its perfect still to this day. Your video is just what I needed, as I have a reasonable knowledge of seek and repair but I'm no guru. These are wonderful radios and the good thing is they can be repaired most times so I will stick with you on this repair just so as I can continue to enjoy using this TX. I will go through it all as you have and let you know what results. I have a problem with my sub display also it works but is not lit and I can see someone has had a whack at it but a little rough to say the least. This is what our hobby is all about a successful repair results in great satisfaction, great on air performance and thats what we want. I thank you again for taking the time to patiently teach us all you have learned, many thanks daryl vk2eat

my kenwood 940s has the same problem in part 1 when will part 2 be posted?

Kenwood TS-940S did you do part 2 yet thanks

I have a TS-940 that got hit by lightning 20 years ago and has been sitting out of service ever since. If memory serves the strike came in the power line and not the RF connector. When it powers up, I get that brief static sound followed by silence. I have a backlight on the S-meter, but no power at all to the main display or the sub-display. I'm hoping it's just a power supply problem. I'm trying to decide if after all this time it's worth opening up to fix. What do you think?

Right were you find the connector mod there is a voltage regulator I can't remember but is 18 or 19 volt is bolt into the aluminum wall that's the one y supply's voltage to the pll board re flush the pin and game over I fixed so far few ts940

Did you ever check the serial number? I don't see Part 2 unless I am missing something.

Working on the same issue, dots - resets work for days then goes dots. Resoldered both the digital and PLL - I guess next would be to scrap out the potting compound - I also reseated the rom

I've got a Kenwood TS-140S that had the display go out. First it got dim then it went off completely but sometimes it comes back on bright then flickers on and off. Wonder where I should start looking, do you have any experience with that model?

These seem to be a nightmare. From what I’ve been reading they sound like they were trouble when new.

Hi. A quick question. I fixed a ft901dm I told you. I'm thinking about taking on a ft-102 for repairs or a kenwood ts-830s or other kenwood hybrid. Do you find the kenwoods better made and designed than the yaesu's? thank you.

was there ever a part 2 to this?

Update...after resoldering, not merely reheating, all of the Digital A board pin connectors and all of the ICs plus the time base crystal the radio has been perfect for almost three hours now. If your radio doesn't have the dots but acts like it needs an exorcism break out a grounded tip iron and the magnifying glasses.

dear ham And as I fix it? Where was the fault? Thank you Paco EA5GU

I DO HATE WORKING ON SOMEONES ELSES MESS!!! I used to be an Elect Tech for a local school system. The "guy" who had the job before me ( he was no Electronics Tech, he was ....... lets say a jack-leg) I could tell when he had been there. He would leave notes to himself. Funny part was , if he had just fixed right the first time he may not have had to come back.

i just acquired one of these and the read out stays at 14.000.00 and low revive and transmit need help

Hi, where is part 2?

It would make your job so much easier and save the owner money in the long run if they didn't fiddle with things they have not got a clue about...1 word comes to mind Cowboys LORL. ....I did have a few choice words to say about them but toned it right down in case any younger viewers are reading the comments...Very best of luck getting it going...I would love to get my hands on a cheap none working one of these Transceivers....Regards from Steve Liverpool UK M0BFM

I would have checked the 3 volt battery first, then alignment of PLL board.

Did you do part 2 Buddy.

Mate !!!!, You're an Amazing Doctor of Radio, I'm Speechless, If You Need an Elder Brother?, I'm Available :-)

did i miss part 2? or is she a parts radio?

nice

Hello, 73 I wish someone could help. I have an equal radio does not work in TX in AM mode, but RX works well. Everything else works fine in all modes ..

part 2 ?

I guess Part 2 was cancelled due to radio being beyond repair :-) Looked pretty nasty with all of the connectors cuts and soldered-back haphazardly.

where’s part 2

Any updates?

Hello Sr. I can see that you are a professional at the Kenwood TS-940S I have the same radio with the receiving and transmission problem, the batteries for the memory back up dead and my radio is unlock for 27, MHz. And I liked that way, I wonder about your shop location and if could get your phone number, I live in San Antonio, TX. I will appreciated if You send me back the information! Thank You very much, God bless. :-)

Where is part 2 of this?

at 17:35 connector left on a angle

940 was a complicated rig...the 430 had same watts...you just need some Inrad filters...way easier to work on and 40 lbs lighter...Kenwood above all others.