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phogren
March 4th, 2013, 04:55 PM
I am still struggling with my latest Kaypro 10. The mother board is 81-469 and has an advent turbo rom v 3.4
If someone has the later K10(with clock and modem and the HD connector on the right next to the FDC not near the center.
What is the character ROM number that you have at U9. the socket is a 28 pin but the rom that was there and in others is a 24 pin.
I tried a kayplus rom but there was no difference in the video. Is it possible it's a video power supply problem? The system works great I can pip files and run programs but the bottom of the video is all screwed up. It has roughly 18 lines and the last 6 lines go up the screen.

phogren
March 4th, 2013, 06:04 PM
1218112182If nothing else these posts are a catalyst for thinking. I tried piggybacking a known good kaypro 10 (older style) on the motherboard. As I feared it has to be on the video power supply. I'll try the motherboard on a known good K-10 and see if the problem is indeed the K-10 video board.

Ahh, the motherboard works fine on another system. So unless my 65 year old brain is malfunctioning it has to be the video board.
It's a Micrex TW-105 94v-0 Any suggestion s on what to look for? anyone have one for sale?

Chuck(G)
March 4th, 2013, 08:06 PM
Boy, that's weird. I went down to my shop and looked inside of a hellbox and there's this CRT board labeled "Micrex TW-10594V-0" It looks pretty much like yours, but there's a wire jumper between the pin near C606 and a hole in the board near R306. It looks to be original, but I don't know what it does.

The odd thing is that I've never owned a Kapro (screen's too small for me), so I don't know if it works or not.

It's yours if you want it--at some time in the past, I'd had visions of scavenging the FBT from it, but the wiring's wrong.

phogren
March 5th, 2013, 05:12 AM
Yes Yes Yes
Please send me a PM with Paypal info.
Have a few Kaypro parts if you are needing anything

k6whp
March 10th, 2014, 08:24 AM
phogren, gents,

I'd go for the video extra board if you want to but your problem seems similar to what I have been debugging over the past week or so on my Kaypro 2X. (I will be posting some notes on my blog later today and welcome PMs at k6whp (at) arrl.net if you want to compare notes.) I would try re-capping the board and that might help.

I tried to upload some pictures to this forum but ran into difficulty, so i am putting up a "skeleton" post on my blog with those pictures. You are invited to visit and see if this looks like your problem. Note that I did not get the problem 100% fixed as there's some waviness to the lines in the bottom quarter of the display. There was a 4.7 uF non-polar cap I did not replace (the guy at the store gave me a 4.7 uF polarized one) but I intend on replacing that soon.

Blog URL:

http://righthandofzod.blogspot.com/2014/03/kaypro-2x-back-almost-to-normal-after.html

Hope this helps and -- again -- am glad to exchange notes with you and offer any assistance I possibly can.

Morrow Bay is a nice place to visit this time of year.

:-)

Good luck,

Bill, k6whp

k6whp
March 10th, 2014, 07:46 PM
http://2.bp.blogspot.com/-3T17GVyMxAU/Ux3jh5T8hgI/AAAAAAAAC1w/5_Lm-nSc0LA/s1600/K2X+Bad+Video+Images.jpg

http://1.bp.blogspot.com/-7do4BTS1o04/Ux3jnmTx5BI/AAAAAAAAC14/hrlWAzPfuIw/s1600/Labeled+Micrex+Board.jpg

http://4.bp.blogspot.com/-yhrj34ECBzg/Ux3kUcVQGNI/AAAAAAAAC2A/3k0PpHATQhY/s1600/Final+Semi-Fixed+Display.jpg

http://4.bp.blogspot.com/-xW9NqCyNax8/Ux3lPojlEiI/AAAAAAAAC2I/xRcG0TLaK6w/s1600/Micrex+Electrolytic+Cap+List.jpg

(I posted this earlier but it probably did not make it -- or else the moderation around here is frighteningly slow.)

Phogren, you may not need to swap the video cards. A simple re-capping will do. I am restoring my old Kaypro 2X and believe it was experiencing the same symptoms yours was. See above. I swapped out all of the electrolytics with 105 degree C one with 50V each (except for the 160 V one). The resulting video came out almost 100% -- there is a little waviness on the bottom quarter of the display. I still need to find a 4. uF non-polarized cap for the board and maybe that will cure it.

Anyway, I am/will be posting my notes over on my blog (http://righthandofzod.blogspot.com/2014/03/kaypro-2x-back-almost-to-normal-after.html) and you are more than welcome to send me a PM at k6whp@arrl.net if you have further questions/comments.

Good luck! You're doing the Lord's work reviving an old Kaypro.

~Bill

k6whp
March 11th, 2014, 11:57 PM
..a follow-up on my previous two comments. I finished tweaking my K2X video controls and got it *almost* perfect. There's a little skewing in the lower right hand corner but it's perfectly legible. I would call your attention to YET ANOTHER control on the board over by the C301 160V 22 uF cap label on my picture above.

I just noticed it tonight and used hat in the series of interactive tweaking I did to restore my video to factory spec. The control itself is labelled "+B ADJ" and its V104 I think.

Hope this helps.

gimgim
March 12th, 2014, 11:57 PM
> I still need to find a 4. uF non-polarized cap for the board and maybe that will cure it.

You can check by making one by using two polarized capacitors in series (both positive or negative together).
Detailed discussion here:
http://electronics.stackexchange.com/questions/21928/can-you-make-a-non-polar-electrolytic-capacitor-out-of-two-regular-electrolytic

ldkraemer
March 18th, 2014, 06:12 PM
Found on ebay:

Kaypro II Computer Toshiba Flyback High Voltage CRT Control Board TLC-134-T-V-0 for $29.99


http://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=2&toolid=10044&campid=5335981329&customid=with-subcat&lgeo=1&vectorid=229466&item=331138438600

Also:
Kaypro II Main Power Supply Boschert Model XL53.3601R for $24.99

http://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=2&toolid=10044&campid=5335981329&customid=with-subcat&lgeo=1&vectorid=229466&item=231167372034

Larry