Successful Monitor Transplants

quicksilver2112

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I thought this would be worth sharing; I recently purchased a 1987 Toshiba TV from a Craig's Ad. Cracked open the case to discover a 29mm neck. Target was a K4600. So far so good; both 9 pin and the donor looked to be compatible in all ways physically, with the exception of the yoke which is far smaller on the donor.

Impedance check at DC:

WG (K4600 Recipient):
V - 8.2Ohm
H - 2.2Ohm

Toshiba (Donor):
V - 8.8Ohm
H - 2.6Ohm

Prospects are great so far.

Performed the transplant to discover that the image looked like crap when displaying the convergence pattern from a Galaxian. After horsing around with various poor results for a couple of hours (swapping yokes) I discovered that the Galaxian Monitor (6-pin male connector) had a transposer (on its WG G07-CA0 Chassis PCB) that scrambles RGB, Ground and sync. So, I put the transposer in series with my test extension cable and bam, an image!

OK, two hours I wish I had back but valuable lessons learnt.

This was a total luck-out, but what a perfect monitor now. The native yoke, while quite different in size, worked with the K4600 in the end.

It's now in my Missile Command and performing awesome. MC has solid image screens that show any and all imperfections in the purity and any phosphor burn.

I've since been picking up any POS old 19" TV's I can find that are pre-1990. However, in almost all cases the tubes have a 22mm neck and therefore will not be directly compatible. My guidance is to look for TV donors with a manufacture date between (roughly) 1978 and 1990. Closer to 1980 the better for obvious reasons. (From what I've learned 29mm / 9-pin necks were phased out in the late 80's.)

Also, K (Blackdogmachine) showed me a Nintendo monitor retro-fit he did that incorporates a (albeit 100V Nintendo) 21mm neck tube with a compatible neck board. I plan to do some research on the chassis used there.

What a rewarding experience.
 

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I was just adjusting my K4600 with a transplanted tube this weekend. (I did manage to touch something while adjusting the width coil, and got a pretty good jolt...)

I forget the TV model it came out of, but the donor CRT was a Matsushita 510ABYB22.

Coil measurements:
Original deflection coils: 9.0 ohms / 3.2 ohms
Donor deflection coils: 10.9 ohms / 3.0 ohms

Picture looks pretty damn good, IMHO. Having just a little difficulty adjusting the width narrow enough, but my coil is in pretty bad shape...

I didn't have an "transposer" to deal with, but I am yet to hook up the degauss coil. The original had a few components (diodes and a capacitor) mounted off of the chassis, and I'm unsure if I need them or not... need to pull out the schematics again and understand the degauss circuit I guess.
 
Shocking

I got the living S$!#@ shocked out of me this weekend too, but it was when adjusting some rings. Nice burn marks; wrist touched something 110AC on the neck board.

In reading there is a golden rule; always keep one hand behind your back or in your back pocket. This way if you take a shock the possibility of it passing through your heart (and stopping it!!!) from hand to hand up your arms is reduced. I did not do this (although it had nothing to do with touching live AC) and my other hand was gripping a metal service cart that was grounded. I felt the jolt go over my shoulders and rib cage and experienced a white out for an instant.

The other safety measure is ALWAYS use an isolation transformer (I was using one); this will serve to collapse the secondary winding field in the event of a surge like I've described (you're full on to line voltage otherwise without an iso).

The double whammy in my case is that I just got this monitor working and was wrapping up the dynamic convergence when the jolt happened. It took out something in the horizontal freq circuit and I'm now debugging that problem! When it rains sometimes it pours...


I was just adjusting my K4600 with a transplanted tube this weekend. (I did manage to touch something while adjusting the width coil, and got a pretty good jolt...)

I forget the TV model it came out of, but the donor CRT was a Matsushita 510ABYB22.

Coil measurements:
Original deflection coils: 9.0 ohms / 3.2 ohms
Donor deflection coils: 10.9 ohms / 3.0 ohms

Picture looks pretty damn good, IMHO. Having just a little difficulty adjusting the width narrow enough, but my coil is in pretty bad shape...

I didn't have an "transposer" to deal with, but I am yet to hook up the degauss coil. The original had a few components (diodes and a capacitor) mounted off of the chassis, and I'm unsure if I need them or not... need to pull out the schematics again and understand the degauss circuit I guess.
 
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