Re: Tech: Tempest and 6100 monitor shakes or jiggles or jumps



Checked everything on the Tempest below except the Zener diodes in the HV section, the resistor on the ARII board (there is no R-81), and the ..47uf caps on the Deflection board. I reflowed all the solder on the HV section with no luck. Checked everything else with no luck. Correct resistors were in stalled at R710 and R610. Swapped out a couple other HV cages I had and they exhibited the same stuff except for the later model one. It only had minor shaking. I adjusted the screen size and double checked the B+. Degaussing coil was not an issue.

While digging thru my boxes of vector parts, I found a chassis that I had capped 2 years ago and it had "new" caps at C100 and C101. I pulled those and swapped them onto the deflection board installed in the Tempest. It too, had REALLY bad shakes at first, but after the caps warmed up a bit, the shakes settled down to just a minor ripple. The old caps tested fine on my ESR meter so I'm not sure where to go. The new caps are an improvement so I'm leaving them in. If any one else has a similar issue and finds a resolution, I would appreciate a follow up. I will be working on more vector monitors in the coming weeks so will post my findings and issues here as well.

Pat D.

Pat D. wrote:
Trying to finish up a 6100 I've had for over a month. Turned out to be a game board problem as well as a monitor issue. Both have been gone thru with very nice image EXCEPT
the bottom of the screen will exhibit the shakes or jitters. Not all the time mind you, but enough to be noticeable and frustrating. HV checks dead on at 19.5 KV with a High voltage probe. All new caps and transistors thru out the deflection board and HV section. Rebuilt power supplies and new Big Blue. LV2000 installed. So far my Googly research has pointed to several things that I might have missed. I'm including them as well as other suggestions below for future Tempest fixers:

1. Possibly the Zener diode in the HV section (I think it is 901)

2. Wrong resistors being used in the R610/R710 position of the Deflection board(non-inductive is correct) (I'll see if these have been changed before)

3. Screen adjustments off and perhaps the Bip pots and LIN pots need adjusting via the setup mode.

4. Bad caps on the incoming power lines into the HV section (although I'm 99% sure I changed them out)

5. 2nd anode wire (fat red one) is too close to the yoke

6. Shield missing over HV cage (it isn't)

7. Cold solder joints (nope- I reflowed all of them)

8. On Star Wars machines, R81 (I think) needs to be increased from 10k ohms to 20k ohms on the ARII board (Does this work on a Tempest?)

9. Ripple on the Low voltage side of the Defl. board. Change C100-C103 (I didn't change the big caps, don't have any on hand)

10. Removing the .47 uf box caps next to R610 and R710 (Not sure why..apparently not used in later versions of board)

11. Bad grounds

12. Interference from Transformer (heck it's in the bottom of the cab separated by a wood shelf)

13. Degaussing coil isn't turning off completely (is this possible?) Heck it's a vector, I guess anything is possible.


I'll be tackling these tomorrow and let you know what I find. I'm getting pretty pooped and need to get to bed. Anything else I should check? I'd really like to get this back to the owner and I'd like it to be as close to rock solid as possible. Please let me know if I screwed up part locations so the next poor schmuck that works on a vector doesn't go chasing a ghost.

Thanks

Pat D.
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