brand new weiya 3129DHSS with odd issue

max 330 mega

The Almighty Bunghole
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so my last chassis died a week ago and i just put this brand new one in. all is well other than this annoying lack of uniformity that has the left portion of the screen stretched out and image not center focused as (hopefully) seen in these pics. ive messed with all the knobs on the chassis and the control board, and this is the best i can get it. what do i need to do to fix this? i used to have this sort of problem with 25 inch wells gardner monitors and never knew how to correct it.


 

max 330 mega

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do i need to mess with the yoke rings or will convergence strips pull the picture in line better or??? HALP!
 

Westcb

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do i need to mess with the yoke rings or will convergence strips pull the picture in line better or??? HALP!


Convergence strips will not help that problem. They help when the guns don't line up and you see red blue etc off the lines.
 

max 330 mega

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so there is a knob on the chassis titled 31 KHZ B. it says do not turn it, as it should be factory set. any chance that is it? also, usually turning the vertical hold either goes screen flipping or steady, could fine tuning that knob fix this? is it possible that this chassis is already fresh out of the box in need of a cap job? ugh its annoying me.
 

Kid Panda

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so there is a knob on the chassis titled 31 KHZ B. it says do not turn it, as it should be factory set. any chance that is it? also, usually turning the vertical hold either goes screen flipping or steady, could fine tuning that knob fix this? is it possible that this chassis is already fresh out of the box in need of a cap job? ugh its annoying me.
Don't touch that B knob, you can overpower your chassis and lose 31K at best, and fry the chassis at worst.
 

Westcb

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so there is a knob on the chassis titled 31 KHZ B. it says do not turn it, as it should be factory set. any chance that is it? also, usually turning the vertical hold either goes screen flipping or steady, could fine tuning that knob fix this? is it possible that this chassis is already fresh out of the box in need of a cap job? ugh its annoying me.


I think the terminology you need to search for would be linearity not convergence. The B is voltage, adjusting B+ should only be done if the voltage is over under. By fine tuning B+ on a Sanyo I got much better white balance but that's the only time I had to adjust. Another time you would want to fool with that is if it was throwing you into high voltage shut down. Can a chassis fresh out the box need caps, absolutely. When was it made? And with your other chassis was the cross hatch evenly spaced? If so then you can narrow down problems with the rings on the yoke. If the yoke itself is not centered up things can be crooked, misaligned etc... I honestly play with nanao and wells much more and haven't had to deal with your exact problem yet otherwise I would walk you through some steps. Hopefully someone else will chime in who had a similar problem. Have you had any luck getting a manual for your chassis yet?

A quick google check showed weiyas coming with B+ not adjusted correctly. Here is a pic of a few models and what the B+ should be set at. A few people did indeed have focus issues with improper B+ set and had blurred/stretched picture on sides and center look ok. Don't follow these numbers but look up your model and see if you are set in spec. Also what kind of pic do you get in 31hz mode vs 15hz? Same issue?
cc8f843f50d1358a2c5833fd2324d64b.jpg
 
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max 330 mega

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never had any geometry issues before.
ill check my manual and see if i can find the B voltage setting and measure it. while looking around the web i came across some info on horizontal non-linearity that had me come up with a few things to try.
excerpt:
E/W Correction Problems
The common name for the adjustments is likely to be ‘Pincushion Amp’ and
‘Pincushion Phase’. They are controlling the E/W correction circuits.
Pincushion Amp adjusts the amplitude of the correction signal.
Pincushion Phase adjusts where the correction is applied on the vertical scan.
Failure of the E/W correction circuit will result in very noticeable
pincushioning distortion of the vertical edges.
Excessive E/W correction will result in barrel distortion of the vertical
edges.
A bad power supply derived from the flyback could also result in similar
symptoms due to ripple or lack of power to the pincushion circuitry.

OK...with that info, and the fact that when i bought these chassis a year ago the supplier had just flown a weiya tech in to fix an entire batch of bad flyback transformers.... im gonna do these things.
1. set up a stepdown 110 to 100 V voltage converter to make sure the chassis isnt getting pissed about the extra voltage.
2. check the B voltage if i can find it/ figure out where to read it from.
3. plug in a 15 khz board and see if issues are still present.
4. try and find a way to determine if the flyback on this new chassis is not outputting proper voltage.
5. contemplate robbing the flyback from the bad chassis if i can figure out it is still good and put it on this chassis maybe?
 
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Westcb

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I would skip number 1. The range is 100-240v for normal operation no way a 10v diff could matter.
2. Hook the one wire to the frame and the other wire to resistor 33 (r33) on a lot of chassis I just looked at but check your manual. Set dc to 200 volts, to make it easy I use alligator clips so you can clip one end to your multimeter leads and the other to the frame/and resistor and they won't move. You will need your hands free to then adjust the pot. Power it up and see what it says. Adjust ever so slightly and see what happens. You can be doing this while on the cross hatch screen. Don't spin the knob, just tiny turn and watch your meter so you don't stray to far.
3. Definitely try this step as B is set independently for the two modes.
4. Testing B plus will answer that :-) so you can skip this one too.
5. Can't hurt but exhaust 1-4 first before you go robbing stuff.
 

Westcb

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Oh also worth mentioning I saw posts bitching about side compression... May be just a design flaw, many models are not particularly regarded as high quality or perfect to begin with. Plus the chassis may not be exactly right for your tube (different curvatures can still run a chassis of the ohm settings are in tolerance but still give a less then perfect picture.)

Your model number seems awful close to this....
http://wiki.arcadeotaku.com/w/File:Rodotron_666_Compression_Fix.jpg

Looks like if you make a slight fix it will make 15hz look much better but 31 looks awful regardless.
 
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max 330 mega

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checked my manual, the B voltages are not listed in it. not sure where to go from here...
 

max 330 mega

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i have emailed the company i dealt with to buy the chassis, and am seeing if they can get the B voltage info from weiya.. seems like a long shot but we will see.
 

max 330 mega

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ok update,
i got the B voltages, and have adjusted the 31 khz b voltage (it was set 17 volts too low.)
this does not seem to have corrected my issue though, here is a new photo, looks quite close to the original one i posted:

gonna connect a 15 khz board to it now and see if the 15khz has the same slinky effect going on.
 

max 330 mega

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seriously, someone has to have seen this issue at least once. paging ttoooddyyy, i wish he still came around. he would most likely have the answer.
 

Bagheera369

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Heya boss....you asked me to check in here, so I have. :D
1) This is not the only forum with monitor folks. Ken Layton, Ohmeron, and several others on the KLOV forums are very well suited to giving help on the Weiya chassis, as they are OPs, or professional monitor repair folks.
2) Compression of that magnitude is usually caused by caps, in most of my experiences.
3) Not only could you have weak caps, but could also be a weak solder connection, as the WeiYa chassis are done with lead-free solder, and they just dont get the same connection quality alot of the time.
4)That is gonna be Horizontal compression, so if you start looking for "WeiYa Horizontal compression" with your chassis model, or the 2929 models, you are bound to find some info.
5) If I stumble across anything else helpful, I'll try to give a shout! :D
 

max 330 mega

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time to get out the ol' capacitor wizard and start checking around i guess. thanks for the reply!
 

Atro

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It looks like it needs a small Yoke adjustment.

yokeEng.gif

It might be just a bit off.
 
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