RJTech RJ-800DVX III Divx Player

[Oklahoma Wolf]

Just got one of these DVD/Divx/Xvid players for Christmas. Because I heard that these tend to up and die on you after a few months, I decided I wanted to void the warranty and see if I could keep that from happening. The player is awesome, and I want to keep it that way. So, I plan to entirely recap the power supply in a month or two, but I thought I'd show you all some pics and get your thoughts on it before I pick the caps.

First, the PSU:



Main filter cap is a 22uF 400v KSJ branded cap. The only other KSJ is that 10uf 50v cap next to the Philips TEA1521P SMPS controller. The rest of the caps are all HLC brand.

Here's the rest of the player's guts on a very small PCB:



There seem to be no caps larger than 220uF on this board, so I'm not too sure if it's that necessary to operate on this one.

For cap replacements I was thinking of general purpose Chemicon KMG, Panasonic NHG, Panasonic EB, or Nichicon PW for that 400v cap and Panasonic FM, Nichicon PW, or Chemicon KY for the rest.

Just wondering though if the EB would be appropriate for the main filter cap though since it's just filtering line voltage. Also wondering if anyone's heard of KSJ or HLC before

[linuxguru]

Re: RJTech RJ-800DVX III Divx Player

I got a similar Chiense-made very slim (~1" tall) unit, but with a small 2-channel IC power-amp (on the same board, but electrically isolated from, the PSU) to drive two bookshelf-type speakers, as well as DB-15 VGA-out connector to a monitor/projector, if needed.

In addition, it has a whole complement of RCA/coax/optical output sockets. My PSU board was also fully populated - both output connectors and most components were present.

I changed the caps on the PSU/audio board, and added an MOV on the AC input. The audio is now crisper and firmer, and the unit stays powered on indefinitely without any overheating issues. We'll see how long it lasts - I'm guessing the drive mechanism will die before the electronics.

[willawake]

Re: RJTech RJ-800DVX III Divx Player

one thing about the small psus in dvd players etc, i have found they are likely to be damaged with voltage surges. i am guessing thats why linuxguru install a MOV. Otherwise recommended to be on surge protector.

that mediatek chip on the main pcb indicates that the unit will be quite nice.

if some chip is getting hot then perhaps add a heatsink?

[Oklahoma Wolf]

Re: RJTech RJ-800DVX III Divx Player

I thought about the heatsink idea, but didn't really check to see if anything was getting hot. Will have to do that soon

This player is awesome so far - haven't found anything it doesn't play yet. It has a 5.1 channel audio out which is proving very useful.

[Rainbow]

Re: RJTech RJ-800DVX III Divx Player

There are two things that fail in these cheap DVD players - power supplies and spindle motors in some types.
Power supplies fail because of bad caps or bad design and voltage spike.
If the motor is the same crap as tray loading motor with only 2 wires, it will fail. If it's brushless motor (with more than 2 wires), it should last much more (they're used in all CD-ROM drives and haven't seen even single one bad).

[Oklahoma Wolf]

Re: RJTech RJ-800DVX III Divx Player

Thanks - I've replaced spindle motors before, so hopefully I can find one for this machine if need be. I didn't really look at that part of it.

I have it indirectly on a surge protector running through the back of my Kenwood home theater receiver (it only gets power when the Kenwood is on), but I like the idea of adding a MOV anyway. Where exactly would I add the MOV?

[linuxguru]

Re: RJTech RJ-800DVX III Divx Player

A good place is after the fuse, but before the bridge rectifier. That way, the fuse also blows protectively when the MOV crowbars on a power surge, which is a good thing.

[Oklahoma Wolf]

Re: RJTech RJ-800DVX III Divx Player

Cool - will do that then. I have a couple friends interested in buying these players too, so I may grab enough spare parts to modify theirs too.

[japlytic]

Re: RJTech RJ-800DVX III Divx Player

Often, failures are related to the electrolytic capacitors in the power supply.
I have reverse-engineered various DVD power supplies on www.eserviceinfo.com with recommended capacitor upgrades, under the member name RE_King .
In this particular player, these are the capacitors I recommend for each rail:
400/450V main capacitor: 47uF Chemi-Con KMG
+/- 12V rails: 470uF 16V Chemi-Con KY
+3.3V (if fitted) and +5V rails: 1000uF 10V Chemi-Con KY
-24V (if fitted) and 10uF 50V capactor near TEA1521P: 100uF 50V Chemi-Con KY

[Oklahoma Wolf]

Re: RJTech RJ-800DVX III Divx Player

Cool - I was going to go with Panasonic, but I do like Chemicon KY too. Just recapped an Antec Neo 480W with a bunch of them.

One more question on the MOV - what voltage rating should I grab... should I stay close to the 120v mains?

The other caps on the board I didn't mention are 1000uF @16v, 470uF @16v, and three 220uF @25v.

Edit - one of the 220's is 10v.

[linuxguru]

Re: RJTech RJ-800DVX III Divx Player

About 200 - 250V should be OK - MOVs tend to cumulative failure as they absorb surge energy, so if you keep it too close to the peak mains voltage, they'll probably fail earlier. Some margin above 1.4 * 110 V will retain safety as well as durability.