Bad Caps in Mitsubishi CK-2690R TV

**bgavin** · 08-01-2009, 11:17 AM

Re: Bad Caps in Mitsubishi CK-2690R TV

I decided to not be a chickenshit, and recap these boards myself.

The OEM caps are VX series radial.
Funny thing is, the only VX data sheets I have are for the axial series. Go figure.

Mouser offered the choice of LXV or Panasonic FC. I chose the FC series.
Both have higher ripple specs than the installed VX, so I figure to be OK.

The boards are slide-in types and an easy removal after the connectors are unplugged.
I'll take digital photos, just in case.

I figure if they still continue to fail after recapping , at least they will be recapped with premium parts.

**ratdude747** · 08-01-2009, 11:02 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

nichicon hm/hn plague's omen?

then again out of speck only makes you out of luck.

vx also refers to nerve gas, i hope that series didn't have that inside

**kc8adu** · 08-02-2009, 06:09 AM

Re: Bad Caps in Mitsubishi CK-2690R TV

did one for a customer a few weeks back.is that the one with the blue antiglare on the crt and a popout drawer with the controls?
if so you will be changing a shitload of caps!
only reason we did this one is that someone had replaced the fly and the crt tested like new.that and the customer wanted it fixed if possible.
about 150 caps later it is perfect again.

**bgavin** · 08-02-2009, 11:56 AM

Re: Bad Caps in Mitsubishi CK-2690R TV

Big oak console on wheels.
Single oval speaker on each side, tweeter above each.
Pop-out drawer for the front controls. Mine takes Viagra, always popped out.

Yeah, there are a lot of caps on those boards, but none looked popped except these two 50/2200.
It sounds like you are suggesting a recap of both boards?

I suppose I could do this, but the local shop is balking at fixing it at all.
Dunno why... there is only one IC per board, and I doubt they are bad.
The rest is discrete component.

Problem is, I don't know squat about procedures for servicing TV.

Both units still work. One smells of frying cap, the other has crappy sound and pix.

The one I bought new still has the full size schematic inside.
Just like new.

**kc8adu** · 08-02-2009, 12:18 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

look for leakage under small caps.
smells like fish.

**bgavin** · 08-02-2009, 02:42 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

I saw some discolored areas on the boards under various areas.
If it smells as bad as that Lock chick Gianni posted...

There are a lot of teenie caps on this board.
Are these the ones you mention?

**Wizard** · 08-02-2009, 04:12 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

I have to mention mitsu tvs, they always needed tons of caps changed. That is why I put estimate higher for these. I tend to do about 40-50 caps in these.

Last one, I had to do this to get audio to sound right and video paths working. These uses lot of 1, 4.7, 10uF in series on the paths, audio processor, vertical ramp generator, and many things. Very poorly done. Ideal is fewer caps especially on signal paths or non-fish cans.

Use the eye on the PCB where spots looks wetted dust coatings and pull caps to check the leads they will look cruddy and ICK! and ESR meter.

Cheers, Wizard

**bgavin** · 08-02-2009, 04:15 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

I am a complete novice at TV.

I can look for discoloration, and replace caps.
What I don't know how to do is trouble shoot the set itself, and do the adjustments.

I have the full schematic, but cannot find a service manual on the internet.
It sounds like I should plan on replacing every cap on both boards.

Also, the bulged 50v/2200uF caps I found... are these the result of something else bad, or the cause of the problem?

**bgavin** · 08-02-2009, 06:34 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

I pulled the board as much as I could for inventory and photos.
I don't know how to separate the HVPS from the rubber boot at the CRT, so I left it connected. It's probably simple, but I don't want to screw something up.

There are a lot more bad caps on this board than the one I could see at first.
A number of these have barfed up their brown guts.

I looked closely at the board surface, and see numerous trails that look like moisture trails or leaks.
I'm wondering if the whole board is fucked up...

Considering the price of a new set, I supposed I can invest in a recap first.

Photos enclosed. I have 21 hi-res photos in the parent directory.

Attached Files

**kc8adu** · 08-02-2009, 08:04 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

much of that is glue.
the dead giveaway is the bad ones will stink when you desolder them.

**bgavin** · 08-02-2009, 10:11 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

I assembled a spread sheet of all the larger caps on both boards.
Jeesus... this thing really runs the gamut for voltages.

Some are 25v, 35v, 50v, all the same capacitance, same diameter.
I figure it would easier to order replacement in 50v and use them for the 25v and 35v caps.

There is a whole herd of 50v / 1uF itty-bittys floating around this board.
I know this is 1987 technology, but is it necessary to recap all the little ones?

**Per Hansson** · 08-03-2009, 12:46 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

Ok, I'm first to go OT

Nice pics, I presume you used a stand and really long shutter time?

What lens for the D200?

**bgavin** · 08-03-2009, 01:02 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

The 18~70, f29, aperture priority, using manual focus, +4 diopter closeup.
White balance selected from a piece of 93% brightness printer paper.
Light source is my high intensity halogen desktop lamp.
Gitzo tripod.

I was on order for 6 months for the 18~200, but could never obtain one before my client deadline (wedding). I settled on the 18~70. It works well, but I really miss the 200 tele.

The 70mm is the equivalent of 105mm on my Nikon SLRs, which is my perfect portrait lens.

**Wizard** · 08-03-2009, 02:29 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

Nice pics!

Yes, the small ones that is what gives you hassles, touch the solder joints with soldering iron, sniff COUGH! ugh. Scrape all the glue off the PCB around the components they will self-circuit in unpredictable ways (note the corrsion!).

The stains on the PCB is not what I'm looking for. It looked like water dripped in there and dried up. The stains is exactly around each little bad caps and is darker (like a oil stain on a dusty stuff). Also other stains looks like rodent had lived there. Did TV smell odd?

Sure that CRT is that fresh? And second, not to belittle you, is this worth doing to hitachis because USA have already switched to DTV and Canada going DTV in about 1 and half years?

Cheers, Wizard

**Krankshaft** · 08-03-2009, 07:21 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

Contrary to popular belief in the US we aren't dumping all our TVs because the FCC says jump.

The only DTV receiver I have in my house is an ATI HDTV Wonder on my computer with DVR software.

Only because SDTV interlaced looks horrible when played back on a progressive monitor my card is able to do HDTV 1080i much nicer when playing back recorded video.

The cable companies still provide analog service on cable and their boxes (if you want premium and HD channels) allow HD content to be displayed on old analog TVs (via component and composite inputs) so they're not going anywhere.

I still feel that LCD and Plasma (TVs not monitors) are in their "infancy" stage reliability wise and I'm still comfortable with the old CRT and RPTV. I'm sure there are many others like me.

**bgavin** · 08-03-2009, 09:59 PM

Re: Bad Caps in Mitsubishi CK-2690R TV

Wizard, my TV system converts digital in the cable box. That problem is a non-problem for me. When cable sucks, I have a DVD library, or chase the wife around the house.

A new TV set here is well over $1,000.
Worse, it is a plastic thing of ugliness, rather than a nice oak furniture piece.
I can buy a lot of caps for much less than $1,000.

Brown goo

Is the brown goo above glue or cap puke? One of those caps is bulged at the top, so I know it is bad.
I chased it through the schematic, and found it has a 50/2200 mate on the other board. I will replace them both.

I've inspected the board pretty carefully and only find a bit of evidence that indicates a cap leak. A few have film on the surface, so I will replace them also. I really don't want to replace a hundred caps unless I have to.

What I don't know about is the black can cap . Somebody made a comment about "fish cans." Are these what you mean?

**Wizard** · 08-04-2009, 06:40 AM

Re: Bad Caps in Mitsubishi CK-2690R TV

The brown goo is GLUE. Used to be tan, age and heat turned these brown and *corrosive* and short circuiting where you don't expect. Scrape those off.

On capacitors topic:
We're talking about *small* capacitors scattered across the all boards. .47uF, 1uF, 4.7uF, 10uF, 22uF, 47uF. I also often find bad 100uF (usually found in vertical amp circuit) 220uF, 330uF, 470uF, and 1,000uF are not as problem unless you find "dark stain" around them on PCB and stink up when heating the solder joints.

You are still focusing on power/deflection section which is good but we do want you to investigate rest of the boards with simple checks. Heating solder joints for these after mentioned small caps will alert you to the stink!

Oh yes, Mitsubishi chassis is also full of bad solder. Watch out for that.

The mitsubishi tv I last fixed this year were full of duff and stinking small capacitors for signal paths and processing (audio IC processor uses bunch of caps around it). This was necessary to get audio to sound right (was just doing silent unless I turn up volume then you hear spitting/pops/crackles and video was POOR. After that, MUCH better.)
Audio paths uses small caps in pairs in series and for video stuff on basic tvs that only processes composite video one cap or poly but on decent TVs probably yours uses two capacitors in series in video paths (Y/C) your schematic will show which type of video signal are especially at jungle IC.

Cheers, Wizard

**bgavin** · 08-04-2009, 09:14 AM

Re: Bad Caps in Mitsubishi CK-2690R TV

I appreciate the advice, but you are using terms that are not familiar to me as a non-TV tech. "Jungle IC", etc.

Q: do you recognize the black can cap?

This TV sound is perfect.
Video started showing a line across the top of the screen.
It then developed a burning stink, so I shut it off.
A cap is definitely burning.

I will scrape off the old adhesive and clean the board.
I was going to use alcohol, unless there is a better chemical for cleaning.

My first thoughts were concentrating on the A/C power supply and bulk voltages. If these have bad caps, they will probably cause other caps to fail deeper into the circuit.

**Wizard** · 08-04-2009, 10:11 AM

Re: Bad Caps in Mitsubishi CK-2690R TV

Replace vertical IC and 100uF cap, check the 24~27V vertical supply resistor at the flyback transformer (this probably what you smelt the burning smell when resistor went up in smoke, check it.). The lines at the top is failing cap that sometimes kill the vertical IC, when this capacitor go high in ESR, the vertical retrace voltage drop by about half and top of picture droops, showing it's lines. Your schematic will show this.

The supply feeds both vertical IC's supply and a anode side of diode, cathode side of diode feeds a cap on positive side (100uF) This said cap on negative side goes directly to the vertical IC. That is pump up capacitor, You will find this ESR is very high. The type of vertical IC I think is AN5522, this one with 7 pin inline and 2 screws holding IC to the heatsink.

On other TV, replace that capacitor as well just for preventive measure.

Cheers, Wizard

Bad Caps in Mitsubishi CK-2690R TV

Bad Caps in Mitsubishi CK-2690R TV

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Related Topics