New Wei-Ya chassis vertical collapse

[Sp33dFr34k]

So we've installed a brand new Wei-Ya chassis to replace my Nanao MS9 yesterday evening.

After switching on the cab, for the first 3 times it did absolutely nothing, as in did not seem to power the monitor at all. After measuring the input voltage at 111v, and switching the cab back on it came alive.

Next problem, vertical collapse, it only shows a bright line in the middle (horizontally) and that's about it. Made sure the remote board is connected properly and tried fiddling with the pots, also on the flyback, no improvement.

Only thing we can come up with is checking for dry solder joints as it seems the solder quality on these things isn't great. Before I pull it out and start with that, is it possible that I've missed something very obvious?

Last thing I want to do is send the chassis back and pay for shipping back and a second round of import taxes on it..

Thanks for any help in advance, I will update the topic with a picture once I get home.

[grantspain]

how did you adapt the vertical deflection header to the wei ya

[PascalP]

how did you adapt the vertical deflection header to the wei ya

I did the same conversion and with the Wei-Ya kit is an adapter cable included to connect the vertical coil (green/yellow) to the chassis.
The horizontal coil (red/blue) is a direct fit.

[Sp33dFr34k]

Here's a picture of the image I get from a Naomi.



I tried reseating/fiddling with the H/V connectors on the chassis, also measured the adapter to make sure it's not faulty, all checks out okay, still have the collapse issue.

Anything you can suggest Grant?

[grantspain]

check vertical size pot
check +24v at tda1675a

[Sp33dFr34k]

check vertical size pot
check +24v at tda1675a

Thanks Grant, I've got 182kOhm at the vsize pot/connector, can't measure much more now as I need the chassis lifted from the cab first. Will let you know once I get it out.

[Sp33dFr34k]

Hi Grant, just measured 24v on pin 1, 14 and 15. Vertical size pot seems normal as well, I also have continuïty between vsize and pin 7 of the IC.

Is there anything else we can check?

[grantspain]

have you actually read the resistance on the vertical pins yet?

[Sp33dFr34k]

have you actually read the resistance on the vertical pins yet?

If you mean the vertical size pot, then yes I have. 0-200kOhm on the pot, and from pin 7 of the IC to ground 150-350kOhm.

Also checked the deflection coils, the horizontal shows 0.7ohm and the vertical one 7ohm so that seems okay as well.

[grantspain]

sounds all ok

[Sp33dFr34k]

sounds all ok

Any suggestions on what else we can check Grant?

[grantspain]

i would suggest changing the vertical deflection ic but the tracks are very delicate so you must use desolder braid

[Sp33dFr34k]

Okay thanks for your help Grant. Anything else you can think of in case that's not it?

[Sp33dFr34k]

Just desoldered the vertical IC, I actually pulled one of the solder pads out by accident , but I will manage to fix it. Ordered a new vertical IC in the UK, will keep you posted how it goes.

[Sp33dFr34k]

I've received the new vertical IC from eBay UK and soldered it in (which was a lot easier than the desoldering part).

Against all odds, it works perfectly fine now!!!

Huge thanks to grantspain for his expertise and PascalP for helping me out!

Strange though that a brandnew chassis arrived with a defect vertical IC, but well I'm glad it finally works now

[PunkicCyborg]

Awesome you got it fixed! Why were you swapping out the MS9 though? It can probably be rebuilt

[PascalP]

I've received the new vertical IC from eBay UK and soldered it in (which was a lot easier than the desoldering part).

Against all odds, it works perfectly fine now!!!

Huge thanks to grantspain for his expertise and PascalP for helping me out!

Strange though that a brandnew chassis arrived with a defect vertical IC, but well I'm glad it finally works now

You're welcome, and it is a good practice to install this chassis 6 times
(3 times in your cab before it worked and also 3 times in my cab before it worked )

[Sp33dFr34k]

Awesome you got it fixed! Why were you swapping out the MS9 though? It can probably be rebuilt

The MS9 works fine, recently recapped it but sadly does not support 31khz, that's the reason for swapping it out.

@Pascal: haha yeah, but you know it inside out now