84' Mitsubishi CS1984R - Startup Issue?

[Rod Beauvex]

I don't have any advice, but just wanted to comment on the set itself. I used to have the 15" version. Great set. Does yours have AV inputs? Mine did not.


Hope you get it fixed. Hard to beleive that set is now 30 years old.

[zeno]

You have one of the old MGA's thats good. They were much better
than the newer ones, MGA actually stooped to rebadging some
Sharps on some models. That really pissed off a few customers
when they found out !! ( he he he I told them)

Anyhows the flyback pix is a bit out of focus but looks normal.
The CRT filaments WONT light without HV.
IIRC there is no "start up" circuit in this set, thats good.
I dont think it has anything to do with the buttons, its just the
long arm of coinsidence at work !
I assume you have a meter. Double check the fuses with it.
A common fault is cold solder on the hoz drive transformer & in the area
of the hoz out transistor & flyback. Also at the on/off relay.
The small black xformer behind the flyback in pix is the hoz drive xfrmr.
IIRC these sets also got cracked PCB's along the back edge............

Dont know your abilities or equipment but this is an easy set to deal with
so if you have the basics we can walk you through......
Let us know.

73 Zeno

[Mad-Mike]

Update...

I just discharged the anode (no current in it anyway), and pulled the chassis (he's right, this thing is pretty easy).

Now for what I have found.

Sounds like no charge in the Anode cap when I discharged it. Either this thing must be pretty good at discharging itself when turned off, or maybe the lack of high voltage on startup has drained it.

Thankfully no cracks in the board. A lot of the solder joints, especially on the flyback side, are not very shiny. Went through and discharged all caps and potential voltage stored to chassis ground to make sure the set was safe for testing.

Using a digital multimeter to test all the fuses, all of them are in 100% working order.

Upon closer inspection, there is a metal rod running up the side to the top of the Flyback, and when I touched on the little round bit, a piece of aforementioned "spring" came off, all corroded and rusty exposing a rusty rod that it must have been soldered to. What would this be doing...it almost seems like it's some kind of ground or fuse that fried or corroded away. Still not sure weather to concern mys elf with that or not.

Another suspicious thing I found was a black relay on the flyback side towards the front labeled RP901 that was loose on it's pads I decided to re-solder it...it's nice and tight now with a shiny new connection.

Looking at the pads for the tiny transformer (HOZ) in the Flyback section, they don't look all that shiny so I will resolder those as well.