(TL/DR = pretty simple fix for power and chroma issues)
I had asked some questions in another thread regarding issues with a Panasonic WJ MX30 and an MX50, but thought I’d just address this in a dedicated post.
Both boards had chroma issues (intermittently green-y to B&W), and the 50 eventually just died, and wouldn’t turn on. This is apparently very common with these boards over time. Did some research and found this dude’s videos:
So, with that and the assistance of the service manuals that I found on this site, I opened them up and tested the capacitors on the power board that he identified (on MX50 C10,C11,C18). They indeed had issues, so I replaced, and can confirm they now seem to work perfectly.
I believe the chroma issues were related to problems with the power board. This may strictly be my case though. I am certainly no expert.
Just wanted to post this to give people who are experiencing the same issues some hope. I know it would be helpful to me. A lot of people told me I should just write them off and find others that work, but it only took a few new capacitors to fix.
So thx to this community for posting links to the service manuals, and bless JVS VISUALS on YouTube.
If anyone has a psu board for the mx50 I’m looking for one. I fused the transformer whilst chasing down this exact problem:)
The xfo is dead. A great mixer, be awesome to revive it.
The B bus is only showing green tone video, so I figure I have the same problem as you did. I figure I should go about it the same way, which is open it up and test out those capacitors. I’ve never done something like this before, any advice before opening up the MX50? I’m gonna allow a friend of mine do the actual capacitor replacement since my soldering never goes well.
It’s been so long I don’t have a great memory of the specifics. But if you watch those videos and match up his instructions with the repair manual from this site you should be good. I think I just replaced the three indicated capacitors. Hopefully this solves your issue. Let us know how it goes. Good luck!
Does anyone have a clue what might be going on with my Wj-mx30, It worked fine for quite sometime beside shutting off and turning back on when pressure was applied to the bottom left corner. Now it seems to not turn on at all. When I press the on and off switch back and forth i get some lights flashing but still does not turn on. I checked the capacitors they seem to be fine.
Oooooh I wonder if a similar repair could help solve the green-tint issue on the AVE-5 & AVE-7! I’ll have to compare service manuals and do a think sometime in the near future.
I recently acquired an MX50 with the usual green output. I recapped the power, analog, digital, and switch boards (pretty much every cap aside from the audio section). And lots of those caps were visibly bad, leaking and swollen.
Unfortunately its still not right. Its a little better, but the A BUS is dim and slightly green; the B BUS is very green. When I feed it a signal from a vhs, it is of course discolored, but also scrambled, so maybe loss of sync. The internal signal generator looks great, not green, and all the switches and pots perform like they should. I haven’t gone through the calibrations yet, but I expect it wouldn’t be so far out of spec as to give the green screen.
There are a whoooole lot of tantalums in there and that worries me, as they go for about $1 per. When I have time I can dig in deeper with a scope, likely in the input or BUS sections, but just want to see if anybody else has seen this behavior. Am I missing something?
There are a lot of trim pots in these which I have had problems with, in an MX12. They trim stuff like Pedestal, Hue settings in the AD section. Cleaning them (spraying with small amount of faderlube, Caig) and working them around a bit eventually worked to stabilise a tendency to colour everything in green.
They were unstable for a good while though, it took a few goes for them to settle down.
I can see from my unit, that the trimpot itself is discoloured and oxidised. it has a metal body.
Tantalum are a pain in the ass if they go bad, they go short. But, if you check them for shorts, if its not short, its still good. Use continuity test on the tants, I’m sure you’ll quickly rule them out as a major problem right now.
Whilst re-capping is not always repair - it’s often involved in repair.
If OP has replaced these damaged caps - they needed to be replaced regardless of whether they were causing the fault. And if they were in the PSU, they certainly needed to be replaced before continuing to look for the fault (in my view)
It’s easy to see damaged components and think THIS is my issue. (I have done it many times) When you are teaching yourself, mistakes will be made - we are all learning.
