Wei-Ya M3129D01-7 Clicking only at standard res

[mourix]

Got this Atomiswave cab with the famous Wei-Ya M3129D click of death. I did a complete recap/reflow based on this sheet I made. The images on there are my board too.

After the recap it still had the relay clicking, but I did notice it does work on medium and high res modes which I hadn't checked before the recap. Only 15kHz sources make it click.

On 31K, B+ is a steady 140V. On 15K, the relay seems to shutoff at about 35V on the multimeter.

At this point I have diode checked all parts on the daughterboard and replaced the relay on it. I also tried to lower the 15k B+ to no avail. Also went over all my soldering.

Can anyone guide me from here?

[grantspain]

do you have a capacitance meter, if so check all the hv poly caps behind the flyback - i am sure one of those causes this fault

[mourix]

do you have a capacitance meter, if so check all the hv poly caps behind the flyback - i am sure one of those causes this fault

Thank you!

I only got one of these cheap FNIRSI LCR-P1 "all in 1" testers but it seems to be incredibly inconsistent.

Just bit the bullet and ordered a DER-EE DE-5000. Will report back.

[mourix]

Got the tester, and tested all film caps on the daughterboard and the ones in the marked areas.
All seem to measure bang on capacitance and all high impedance on 0-1kHz, <1 Ohm on 10kHz, and close to 0 Ohm on 100kHz.
Also tested the relay on the main board powered out of circuit. Also perfect.



Any follow up ideas?

[mourix]

Update.. been testing pretty much the whole circuit relating B+, and found that the 15k B+ pot is actually 95% maxed out.

That cant be right, right? Maybe someone has been here before me.. I did mark it before I started twisting it.

[grantspain]

next step would be dummy load the HOT and see if b+ is around 74v, no signal attached

[mourix]

Shouldnt I try adjust the B+ first in case of someone before me twisting the pot to maximum?

Found my original image:


As you see, 24/31k pots are about midpoint while 15k is maxed out. I am contemplating to put 15k to mid as well and see what it does.

[mourix]

Well, I tried the mid low to high range on the 15k pot, and it did not stop the relay shutdown situation. At least 31k is still working so I haven't made it worse so far...

[grantspain]

when no video signal is attached does it power up and if so what is b+ reading

[mourix]

The clicking and B+ climbing to ~35V before shutdown happens without signal too.
The 15K B+ pot range can make the spikes end between about 30 and 40 volts.

[grantspain]

the only other thing i can think of is IC5 which has a microcontroller ic

[mourix]

The schematic does not have IC5, but has IC6 twice. Do you mean the 3129X001 or 3129X002 block?

Update:
Ahh, this one I guess:


That would be unobtainium without a parts chassis, I imagine?

[mourix]

So I checked even more at this point and was ready to order the PIC16C54C to program... The module is fckn potted:


I do own a NOS Rodotron 666A PCB and am considering borrowing the unpotted module from it:


Now watch me destroy both...

[turntablism]

I hope you can repair it.
I had the same problem but was lucky enough to find a replacement chassis.
good luck !

[mourix]

Thanks. I am not giving up here. Way into the deep end:



Even already reverse engineered/copied the IC5 module as I had it out for transplanting:

[mourix]

Update... Putting the NOS IC5 in did not fix the issue....

[grantspain]

dummy load the HOT collector pad with a mains lamp, prove whether its supply or deflection related

[mourix]

Can you instruct a bit more? Am I supposed to remove q36 and put a bulb across?

[grantspain]

if you isolate the leg of q36 from the pad and then add a 220v 40w lamp to the pad of q36 and a ground it will act as a dummy load and the chassis will power on so you can check the b+, it does not need to be connected to the tube to do this
you can remove q36 if you wish

[mourix]

(This was quite a stressful part of the project as I accidentally set my step down converter to 115V in fortunately it only blew up the transformer itself)

I've now removed q36 and dim bulbed it. The issue stays. I get a perfect 135V and a bright bulb if I apply a vga signal, but a clicking/flashing bulb at no signal and 15k.



I have also attached my test notes in pdf. Also replaced IC9 but its clear its not the fault.