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Main => Monitor/Video Forum => Topic started by: pinballvideojuke on July 26, 2016, 12:59:07 pm

Title: Neotec NT500-DX Width/Pincushion problem
Post by: pinballvideojuke on July 26, 2016, 12:59:07 pm
Hello, anyone that has seen this problem, please send me a message. If you know how to fix it, that is!
This is a 27" Neotec NT500-DX from a BBH Pro, so I can't replace with LCD. I need to fix this one or find a suitable replacement. It's a flat tube, by the way.
I've replaced every single electrolytic capacitor and tested all the high voltage poly/MEF caps.
Help!
I have many arcade and pinball parts and could be a resource or help to you in the future! :-)
Title: Re: Neotec NT500-DX Width/Pincushion problem
Post by: grantspain on July 26, 2016, 06:11:51 pm
i am not familiar with your chassis but other chassis with this issue (sanwa) has been down to flyback or (hantarex) east/west correction diodes or pincushion control ic(nanao)
do you have any adjustment on horizontal size at all?
Title: Re: Neotec NT500-DX Width/Pincushion problem
Post by: big10p on July 27, 2016, 10:52:08 am
You haven't said exactly what the problem is. If you can't adjust width enough to fit the whole screen, try adjusting the width coil.
Title: Re: Neotec NT500-DX Width/Pincushion problem
Post by: pinballvideojuke on August 03, 2016, 01:06:42 pm
Sorry, the problem was in the title, but not explained very well.  It's picture is too wide and pincushioned. There is no width coil on this chassis. The width and pincushion are controlled digitally with on screen adjustments. Using the on screen adjustments, horiz size does nothing. Pincushion does nothing. I believe all  other adjustments work, like vertical size, horiz position, etc. If you move the picture enough left or right, you can finally see the edge and it's pincushioned. The focus adjustment on the flyback also does not do anything.

If this is indeed a flyback, where could I find one?!




Title: Re: Neotec NT500-DX Width/Pincushion problem
Post by: pinballvideojuke on August 03, 2016, 01:15:35 pm
i am not familiar with your chassis but other chassis with this issue (sanwa) has been down to flyback or (hantarex) east/west correction diodes or pincushion control ic(nanao)
do you have any adjustment on horizontal size at all?

No, there is no adjustment at all for width and pincushion. I've checked all diodes, I believe. I replaced IC601 which is a TDA9116. From the pdf datasheet: This IC controls all the functions related to horizontal and vertical deflection in multimode or multi-frequency computer display monitors.
Replacing this chip changed exactly diddly squat.
I replaced Q717 which, from what I am told, controls the width. Also replaced Q709 and Q710, someone else said it could be one of them and I had them in stock. No change.
Title: Re: Neotec NT500-DX Width/Pincushion problem
Post by: ed12 on August 03, 2016, 01:41:00 pm
the eeprom is noted for going south on them units
24c18 I think it is
I am just d/l the schematic again so I will post back the location

ed
Title: Re: Neotec NT500-DX Width/Pincushion problem
Post by: ed12 on August 03, 2016, 01:59:16 pm
ya ic902
this is the eeprom
if u can get a factory copy of the .bin u can burn a new 1 yourself
and replace the old 1
here is what happens
if u look for it ? it is at the front of the chassic  and a scant 1/4" from the bell of the picture tube
so it see's static discharge when u power up/down
thus corrupting the eeprom
!!caution here.. do not put in a blank eeprom!! or u will destroy other parts



ed