B&K467 CRT Restorer/Analyzer attempted restore

[Bad_Hambre]

I have picked this bad boy up, with the intent to test all my monitors and to use it on any new sets I might get. Started off with just testing my 19" inch CR31 tube I was using as a donor along with a WG K7000 chassis. Anyways, I was able to set both HTR voltage and G1 voltage, but ran into problems when trying to set the G2 cutoff for Green. I was able to set cutoff for Red/Blue. I also tested the other funtunality "cant remember which one exactly" and when making adjustment to one, it was moving one of the other colors. Figured since G2 cutoff is messed up, it might explain why other needles were moving as well.

So i did the next thing which was to give it a reflow at the back of the board. Then I ordered a cap kit, I also ordered and replace a few resistors that look like they were in some bad shape. I checked both the manual, and matched the physical color bands to verify the values were correct. But now I can't set up none of the cutoffs for any of the colors. I've asked around for anything else i might have missed. Was given some good suggestions like reflowing the joints on those dials, which i have now done. Was also suggested to check the resistance on the dials as i turn them. Have not done that one yet, but seems a bit suspect that those dials would all just fail.

What are more suggestions? The service manual has this

One G2 control fails to adjust properly.
1. Collectors of Q2, Q3, and Q4 with scope for typical square wave. A straight line indicates a bad transistor.
2. G2 controls R49, R50, and R51.
3. Transistors Q5, Q6, Q7.
4. Multiplex generator voltages and waveforms.
5. ICIA, ICIB, IC2C, ard IC2D.


All G2 controls fail to adjust properly.
1. 12BH7A tube V1.
2. Transistor Q1.
3. Rectifiers Dl thru D4.
4. Transformer T1.
5. Capacitors C11 and C12.
6. Resistors R41 and R43.
7. Multiplex generator waveforms.
8. IC1A, IC1B, IC2C, and IC2D.

I think I replaced the resistors that it mentions. I will check again next chance i get to work on it.
And I replaced those caps as well. Polarity is good from what i cabn see.

 

[Bad_Hambre]

Update log:

Still no luck. I replaced transistors Q1-Q10. One thing to note, D1-D7 are labeled as 2n5550 on the diagram and D8-D10 are PN3643. But checking the Q10 transistor, it was a 2n5550. So I replaced Q10 with the 2n5550 upgraded part from arcade parts and repair. I also replaced R41/R40 resistors, both 470k ohm on the diagram and the color code. I'm not so sure about Q10, if it would be better to use the PN3646 transistor or not? Q10 isn't even mentioned in the troubleshooting section for G2 so probably wont worry too much about it for now.

Next things i will be looking at is replacing Rectifiers D1 thru D4 which are identified as Rectifier 600 PIV , 1 Amp on the diagram. Will put out an order tonight. Also will be checking out G2 controls R49, R50, and R51 resistors. I'm having trouble locating them on the boards, would like to verify their colors first before i just order according to the diagram but looks like its worth taking a look. I did forget to check the knobs themselves, will be doing that tomorrow just to cover all my bases.


-Final parts to get

12BH7A tube V1
Transformer T1
Multiplex generator waveforms
IC1A, ICIB, IC2C, IC2D

Hopefully these parts wont be difficult to source. I did see the transformer on ebay, but it cost $43. Chips shouldn't be hard to find either. A little worried about the tube. Not sure what they are referring to with the multiplex.

 

[Bad_Hambre]

-Quick update:

Messed around with the G2 knobs. Verified they are the controls for G2 red/green/blue (R49/R50/R51). Measured all of them and they all read low at first, but got close to 50k ohm once I turned the knobs all the way clockwise. Might just check solder joints all over again just to make sure everything still making a solid connection. Was difficult to measure and turn the knob, so i just measured at different positions for the knob. The manual says these are 10% tolerance but im not sure if that means they should be reading from 45k-55k from all the way counter-clockwise to all the way clockwise?

Thats it for now. Should have some time to check solder joints tomorrow and will order the diodes tonight and start looking for other parts.

 

[benime]

-Quick update:

Messed around with the G2 knobs. Verified they are the controls for G2 red/green/blue (R49/R50/R51). Measured all of them and they all read low at first, but got close to 50k ohm once I turned the knobs all the way clockwise. Might just check solder joints all over again just to make sure everything still making a solid connection. Was difficult to measure and turn the knob, so i just measured at different positions for the knob. The manual says these are 10% tolerance but im not sure if that means they should be reading from 45k-55k from all the way counter-clockwise to all the way clockwise?

Thats it for now. Should have some time to check solder joints tomorrow and will order the diodes tonight and start looking for other parts.

Tolerance values typically mean the part has a variation of up to 10% of its nominal value. For example, you buy a 1k ohm resistor with 10% tolerance, it could actually be 900 ohm and be within spec.

So if your pots are 50k and 10% tolerance, then the maximum resistance would be anywhere from 45k-50k when turned all the way, if they're turned all the way the other direction they should be 0 ohm. How the resistance changes from 0 - 50k when you turn the knob will depend on whether it's a linear or logarithmic type.

HTH

 

[Bad_Hambre]

Tolerance values typically mean the part has a variation of up to 10% of its nominal value. For example, you buy a 1k ohm resistor with 10% tolerance, it could actually be 900 ohm and be within spec.

So if your pots are 50k and 10% tolerance, then the maximum resistance would be anywhere from 45k-50k when turned all the way, if they're turned all the way the other direction they should be 0 ohm. How the resistance changes from 0 - 50k when you turn the knob will depend on whether it's a linear or logarithmic type.

HTH

Gotcha. I dont think I read 0 when all the way off which is why i was questioning the resistance range. All the way open should be 50k with the 10% tolerance. But closed should be 0.

 

[advans14]

Ive fixed and restored a broken one of these before. Good unit.

 

[Zepherino]

Reflowing and recapping is a good start. While the BK467 is a very well regarded piece of kit, they are pretty old, and more often than not are in need of maintenance.

If you haven't already, you might want to join this BK Rejuv Facebook group https://www.facebook.com/groups/503454524641474

 

[Bad_Hambre]

Update:

Replaced D1-D4 toady, still got nothing on g2 voltage. So far i've replaced the cap kit, many major resistors (all related ones), 1-10 transistors, and diodes 1-4. Only things left to check is the tube (doesnt look damaged), transformer, and some of the chips.

 

[advans14]

Id look for broken switch wires. Let me know if you need any ref pics.

 

[Bad_Hambre]

Id look for broken switch wires. Let me know if you need any ref pics.

I would like to see those reference pics!

 

[Derick2k]

I just got myself a 467, going to do a full teardown and refurbish it if I can. If I notice anything that might help you I will let you know.

 

[hatmoose]

These are my unsorted notes collected from the intertubes

Start of Unsorted notes part 1

CRT rejuvenator BK precision 467

Mine needs a restore…
"The G2 setting knobs under the meters independently set the G2 voltage of each gun but I found each knob had an influence on the other G2 settings. By adjusting the 3 knobs together it could be set up ok. I am a retired Tv serviceman who was self employed for over 40 years and never seemed to have the time to repair my own stuff when I could make it work somehow. Now I am retired I have lost my mojo for doing any electronic work."

This guy has EXACTLY my problem (G2 setting on each also impact the others)
https://www.videogamesage.com/blogs/entry/429-bk-467-crt-testerrestorer/
TL;DR just in case that web page disappears
The major one was R70, which was connected to the tube itself was open. Two other resistors, R44 and R37 were also out of spec. After replacing these, I put the thing back together (frustratingly you have to reassemble the whole thing in order to properly test it.
Unfortunately there is no R44 on the parts list
But checking the schematic its 100K 2W - have added it to the shopping list

This is an exceptionally rare high quality schematic, the others are blurry and unreadable

Sticker repro

Set up chart
BK setup setup chart for various tubes is here (1999) is in downloads and also

This application has more recent stuff
https://github.com/dangermousehouse/tubular

Great resource here, parts list and etc - feels like it might be a tiny bit fast and loose in some places but a good primer
https://crtdatabase.com/faq/bk-precision-490-and-467-crt-tester

Good website here
https://sites.google.com/view/mikesarcade/kens-korner

Good discussion here
http://forum.arcadecontrols.com/index.php?topic=156199.0

Repair log here
https://forums.arcade-museum.com/threads/b-k-467-repair-log.478273/

Adapters
This is a primary source that talks about what each adapter is for

Short list of adapters to look for
CR-1
CR-3 Many Sony
CR-5 Other Sony
CR-6
CR-14
CR-15
CR-18
CR-19
CR-21
CR-23 Many Arcades (19” raster)
CR-28 Some other arcades
CR-30 http://gameroomtech.com/HostedContent/Documents/bk-cr30.jpg
CR-31
CR-36 (supposedly useful?)
CR-40 (supposedly useful?)
CR-71 (supposedly useful?)
CR-XA (universal, notes below)

This site has pinouts for a few adapters
https://arcarc.xmission.com/PDF_Monitors/

This document has the pinouts for every single adapter at the back, so you can make your own (or hook up the universal one)

CR23 is the adapter that is used for Some of the most interesting Sony tubes, the ones in the PVM/BVM

Making universal adapter (CR-XA)
Some good info here including this chart
http://forum.arcadecontrols.com/index.php?topic=35631.0

It’s not really ecconomical to make a perfect “v2” replica, but you could make a 467 appropriate “v1” adapter When the parts come into stock in November

Black
Black
Grey
brown
Violet
Red
Green
Blue
Orange
Yellow
Yellow
White
White
Black
Black
I think you are going to want 18AWG wire if you can..

Thhs is a fun advertising brochure from the 70’s

End of unsorted notes part 1 - part 2 with that parts list and those sweet PDF's coming shortly

 

[hatmoose]

Unsorted notes part 2 - including the much coveted clear schematic PDF

End of unsorted notes part 2 - part 3 with the parts list coming soon

 

[hatmoose]

Unsorted notes part 3 - Digikey parts list

Parts list for my 467 specific failed parts, as well as all the other frequently failing components.
Parts list for CR-XA (this is the ver.1 variant of the adapter)

End of unsorted notes part 3 - that's all I got, hope it helps

 

[nem]

I have the same issue as @Bad_Hambre with my 490. It is driving me nuts. It is a very clean unit that didn't really have any broken solder joints.

2BH7A continuity is OK, I have no other means of testing
Transistor Q1 checked
Rectifiers D1-D4 checked
Transformer, apart from the G2 controls the unit works fine?
Capacitors C11 & C12, replaced
Resistors (R40,) R41 & R43 checked
IC1 & IC2, removed and checked

I hate taking the thing apart, I've already broken connections to two of the lamps.

 

[Bad_Hambre]

Unsorted notes part 3 - Digikey parts list

Parts list for my 467 specific failed parts, as well as all the other frequently failing components.
Parts list for CR-XA (this is the ver.1 variant of the adapter)

End of unsorted notes part 3 - that's all I got, hope it helps

This is all great stuff and will be super helpful even if I think I have replaced most these components.

 

[Bad_Hambre]

I just got myself a 467, going to do a full teardown and refurbish it if I can. If I notice anything that might help you I will let you know.

Good luck! And luckily, there is not a lot of screws to keep track which does make this a bit easier to tear apart and put together.
But that's where all the positives end when it comes to servicing this bad boy.

 

[Bad_Hambre]

I have the same issue as @Bad_Hambre with my 490. It is driving me nuts. It is a very clean unit that didn't really have any broken solder joints.

2BH7A continuity is OK, I have no other means of testing
Transistor Q1 checked
Rectifiers D1-D4 checked
Transformer, apart from the G2 controls the unit works fine?
Capacitors C11 & C12, replaced
Resistors (R40,) R41 & R43 checked
IC1 & IC2, removed and checked

I hate taking the thing apart, I've already broken connections to two of the lamps.

When you do it lot of times, it does get much easier, but it is still a pain to take everything apart, replace a few components, put it back together to test, take it apart again and repeat.