Kenwood TS-820 Display problems-here’s HOW I fixed it

[@neilcarter1549]

Thankyou. 😃 This fix worked 100% for me. My display just died, and no amount of spray on the upper & lower connectors of the DG-1 fixed it, this time. My issue ended up being corrosion on the inside posts on the 2 cct boards of the DG-1 unit. A quick spray and clean, as described, resulted in bright display again. Great vid and very much appreciated.

[@propagating-radio]

That’s awesome Neil! I’m glad this helped.

[@624radicalham]

Help me out if you can. When you say "inside posts on the 2 cct boards of the DG-1" what exactly are you talking about? Are you talking about 4 screws that hold the boards, or the actual MOLEX connectors on the DG-1 board had to be sprayed and re-seated? In other words ... you had to take apart the DG-1 casing and take out both boards and just spray and re-seat the MOLEX connectors?

[@neilcarter1549]

@@624radicalham Hi. Yes remove the DG1 from the chassis. Then seperate the 2 boards. Once separated, spray the pins that go into the opposing board's molex connectors. Reassemble/rejoin the 2 CCT board's. Then reinstall the DG1 back into the radio. This fixed mine Goodluck and Cheers.

[@624radicalham]

@@neilcarter1549 Thanks! Tried it once but without giving it full attention so i shall try again and pray for results. Your reply is much appreciated!

[@tinker464]

Thank you my 820 has same issue so I will clean mine up and hope to get my rig back on the air

[@propagating-radio]

I hope it helped!

[@624radicalham]

THANK YOU for this! Coincidentally I had recently discovered your channel and just yesterday I bought a Kenwood TS820 and has the erratic display. To know that just a simple deoxit cleaning, in your case, brought it back to life gives me hope. Appreciate the detailed shots showing how to access and remove the boards. Mine has no mic. Having trouble finding the mic pinout online. I've downloaded the service manual to have a look. One would figure since the radio has been around 4 decades that a simple pinout diagram would be everywhere.

[@propagating-radio]

It’s wild how much the available information varies. I’ve had no trouble finding an obscure spec for an old Hallicrafters, but couldn’t locate the same specs for a TS-430. Weird. Hope you get that TS820 display sorted.

[@624radicalham]

@@propagating-radio It's so true, despite hundreds of thousands of these hybrid and later the 430/440 sold. I've found the groups IO on Kenwood hybrids quite helpful. Thanks for your awesome channel.

[@propagating-radio]

@@624radicalham thank you for the kind words.

[@Fireman9143]

Hopefully you found the answer. The operators manual actually has the mic wiring diagram. It's easily found online

[@robertarchuletta2498]

Good job!

[@kevinmccool3719]

Another failure I've seen is logic chips gone bad. Have repaired many a DG1 in the past.

[@propagating-radio]

Interesting. Have you been able to source replacement chips?

[@bjrnerikbjrna7175]

Also solved the problem for me. Thanks for this advise! .

[@propagating-radio]

Great to hear!

[@edman209]

I got the same radio and I am concerned that I will have do to this because my display is all fuzzy but its there sort of but not really I can read the numbers but it makes it hard to know what frequency I am on.

[@propagating-radio]

is the display dim too? Wondering if you have a voltage supply issue in the display.

[@edman209]

@@propagating-radio No the numbers are funny like it’s bleeding in a little bit like I could see that say the numbers 28 but I’ll be fuzzy if I’m trying to say 25 or whatever so it just looks like all the numbers are bleeding into each other sorta really want to avoid taking this thing apart though

[@propagating-radio]

@@edman209 I don’t think I’ve seen that problem before. There is a Groups-io group called Kenwood Hybrids. If you join that group and post your issue there, someone may have some advice for you.

[@ebones6957]

Too bad you couldn’t identify exactly which re-soldered joint fixed it. I have a similar unit, I just started looking at. I tried reflowing the solder joints on the board with the large connector, no luck. Next the other board. It’s been difficult with my old eyes and shaky hands, kinda takes some of the fun…but still enjoy it. Next I’ll break out the scope and DMM.

[@propagating-radio]

@@ebones6957 it can be a lot of fun to fix your own gear, but I definitely know the frustration that can come with it. Hope you get that problem chased down.

[@Fireman9143]

I'm searching everywhere for a fix to make the digital display match the dial VFO. I see your radio is also off. Have you found a fix for that?

[@propagating-radio]

@@Fireman9143 I haven’t found a fix for that either. It’s annoying though!

[@Fireman9143]

@propagating-radio I realized that the 25kHz calibration beat was accurate with the digital readout, so I took the vfo dial apart and shifted the plates to match the digital. It was a pain because the middle plate set screw is not easy to access. Best bet is to remove the whole thing, hook it up outside the case, and get all the numbers lined up. The hard part was getting the 5 in the exact right spot. The first time I did it, the numbers were just a bit off, and I spun up to 500 they were not in the middle of the window. When the big inner dial is adjusted to 0, set the middle dial so the 0 is in window of the outer dial with the 5 just to the right in the 9 window. Snug it up and spin it all the way around to 500. Make sure the numbers stay visible in the middle of the window. If they are a little left or right, adjust the middle dial slightly. Everything should be within 1kHz of the 25kHz cal beat as you go up and down. I did find 1 youtube video explaining this, though I learned the hard way about double checking the full scale is lined up.

[@propagating-radio]

Excellent writeup! Thanks a lot!