Linear Trim Pot on Weiya remote adjustment PCB

[billd420]

Hello everyone-

While installing my new weiya chassis on my 29" toshiba tube, I managed to crush two of the linear trim pots on the remote adjustment PCB. Unfortunately, the weiya manual doesn't include parts ratings. The chassis I got (I believe) is the 666a model. Its sold by highway entertainment as the "blast city replacement chassis".

The two pots I broke are labeled "103" and "204" both on the pot and screened on the PCB. I was able to find a "103" pot on my Sega ST-V motherboard, however I dind't have any "204" pots on hand.

Does anyone know the actual sizes of the "103" and "204" pots? I found some "103" pots on ebay, and they're listed as 10k linear trim pots, as seen in this picture:
http://www.thedigitalshop.net/iccpix/2655.jpg

I'm not possitive, but I want to say the "204" pot is a 200k ohm linear trim pot. I'd hate to put the wrong value and fry something on my chassis however.

The two pots in question control brightness and contrast. The contrast pot has been swapped out, so I can adjust that. The brightness is slammed to 100% without a knob in place, so the picture is very washed out.

Please help!

[grantspain]

204=200kohm
103=10kohm
the chassis you have is a rodotron 666b1 for the blast city,it is a modified 666a chassis

[billd420]

Grant you're a lifesaver!!!

Are Rodotron and Weiya chassis the same? This chassis came with a weiya manual.

Out of curiosity, what has been modified on the chassis to make it a 666b1 instead of the 666a?

Also, once I have it up and running well, if you're interested I can do some side-by-side 15khz and 31khz comparisons. I have the proper video splitter harnesses that I can duplex a 15khz signal between my Nanao MS9-29A and my WeiYa, as well as the 31khz signal between my Nanao MS2932 and the WeiYa. Might be interesting to see how the compare.

Cheers!
Bill

[Ken Layton]

Rodotron is who makes the Pentranic chassis. No connection to Wei-ya at all.

Never heard of Highway Entertainment or Blast City. Where are they located? Can't be in the USA.

[billd420]

Ken- Highway Entertainment is an arcade distributor out of Australia. Blast City is in reference to the cabinet the monitor came from, the Sega Blast City. Here's the chassis I purchased:

http://www.highway.net.au/parts/monitors_chassis/5372_1.html

Grant- I found some 1W 200K Ohm trim pots on ebay, however they're stamped "502" (or is it "205", cant tell from the pic). Will these work? Here's a pic for clarification:
http://i13.ebayimg.com/08/i/000/eb/a8/8122_1.JPG

Thanks a lot guys!
Bill

[grantspain]

yes funny this,wei ya and rodotron are different companies BUT they both use  the same base chassis,all they do is put in their particular choice of components
if it is a wei ya it will be a ch3129b which is almost identical to the 666b1
the difference from the 666a to 666b1 is the custom ic's,high voltage horizontal caps and some inductance coils-maybe the flyback but not sure
you will find the 31khz is stunning and the 15khz will have heavier scan lines
i know as i have just done this very same test be replacing a nanao 2932 naomi chassis with a 666b1

15khz


25khz


31khz


as long as the pot is 200kohm then thats fine,normally 204 means 2---0----4x0'2=200000,200k
i would say 205 is a 2M pot,could be wrong i guess

[billd420]

Again, thank you very much for your help Grant!

Thats good to know that the 2932 monitor can accecpt ch3129b/666b1 chassis. I might just have to upgrade to tri-synch in the near future.

I'm going to be using the Weiya chassis primarily for 31khz games. The only time it will see 15khz is when I do 3 and 4 player cabinet linking.

The comparison tests that I plan on conducting are going to be pictures of the dot cross hatch tests and the color bar tests (15khz will be the CPS2 monitor tests, 31khz the Naomi). If you're interested, I'll post them here.

I decided to skip on the "205" labeled pots, and grabbed some that look to be the correct pin pitch that were listed as 200k ohm pots. Hopefully I'll be able to adjust the brightness again...

Can broken remote adjustment pots break my chassis? I'm concerned that too much brightness was passed to the chassis/tube. Hopefully no irreparable damage was caused.

-Bill

[grantspain]

very interested to see your tests,i do have grid patterns from 31 and 25khz that are good-the problem with these tri syncs is when they run 15khz as you get linearity problems(compression) and some pincushion issues

don't run the chassis on full brightness for too long as it may damage the tube(may)