ViewSonic P95f+ capacitor value

[Yanitzch]

Hi!

My trusty ViewSonic let me down this week.  The image was squeezing from sides to center and it finally make a lot of smoke and really bad smell!

I opened it and 2 capacitors and 1 resistor are fried on the main board.  It's still working but the image is squeeze a by 30% in the middle.  I email (no answer in 6 days!) viewsonic.  Today I called them and they give me a phone number for service but the guy want to charge me to fix it, no interest in helping me a bit.

My question is: were I can find the value of C440  C438 and the resistor between them (R465, not sure since the board is now too black).   And any chance the big SLA5046 is damaged from the small fire?  It's just so close of those caps...

Thanks in advance,
Yanick

[grantspain]

have you got an hour glass effect?

[Yanitzch]

No, just plain squeezed.  With the control, I am almost able to stretch it horizontally correctly.  But the image is not ok (sprites/fonts bigger on side and thinner on center).

Yanick

[grantspain]

unless you can find it on the net you will have to purchase a schem through a distributor or a tv shop
have your caps actually exploded?

[Yanitzch]

In fact, i think it exploed.  I did not ear any noise since I play with alot of volume   But  when I saw plenty of smoke, I unpluged it right away!  I was able to find the plastic housing of both caps, but the value are not exactly the same.  So I will have to buy the scheme or take a 50-50 chance?

Last time, you helped me a lot with my defective Polo25.  I changed all the caps from a kit you suggested me.  But some of them were not the exact same value.  I installed them anyway, and the monitor is still working like a new.

Any suggestion?  I can't conviced myself of throwing away a (almost) still good CRT.

Thanks alot for your precious help,
Yanick

[grantspain]

take a 50-50 chance,what are the values of the caps and also have you tried to read the resistor value with a multimeter?

[Kevin Mullins]

What is the MODEL of Viewsonic?

Take a poke around here maybe:
http://www.eserviceinfo.com/equipment_mfg/Viewsonic_3.html

[Yanitzch]

No did not tried reading the resistor value.  I am at work right now, so I will post the value next morning.   Stupid question: can I read the value of resistor still on the board or I should remove it?  Thanks again.

[Yanitzch]

Kevin,

It's a P95f+ .  I looked around already on this site (and others) with no results.  But thanks anyway.  Maybe the scheme is just common with another model and it's why it seems difficult to find.

[grantspain]

i like to remove any component first to read it,normally a resistor frying is a sign of a more serious fault elsewhere i.e the ic it feeds

[Kevin Mullins]

It's a P95f+

Duh... I totally overlooked the model in your description..

I know I have found some oddball schematics on that site before.... figured it was worth a shot.

[Yanitzch]

The resistor is standing just between the 2 caps and it's why it's burnt.  In fact, I am not sure it's fried.   I'll check tomorrow for the value.

[Yanitzch]

Ok, so the value marked on the housing of the dead caps are:

3.3µf50V and

4.7µf50V

Should I just put both at 4.7, both at 3.3 or taking 50-50 chance? 

And R465 reads 7.2 ohm, so maybe it's still good?

Thanks,
Yanick

[grantspain]

well its like pissing in the wind without a schem so if you want to take a chance then get 2 of each cap and try both positions,the worst that will happen is they will explode(just don´t have your face anywhere close when you switch on)
i reckon the ic is dead which caused the problem in the first place
good chance the resistor is o.k

[Kevin Mullins]

Are there any kind of recognizable color stripes left on the resistor?
(at least enough to get a general idea of what it's value may have been)

[menace]

I've heard (and had 2 myself) of viewsonics that blow their flyback and hot--check those before you power back on--its unlikley (but not impossible) that your problem is those caps --they were just the weak link for whatever circuit blew inside the monitor.  In all honesty unless you have these parts on hand i would just go to a pawn shop and pick up another one...

[Yanitzch]

Well, this story is coming to an end 

Just for your info, I was able to get the values from a quick chat with Tim T. at Viewsonic.  He was kind enough to provide me the info I needed.

So,
C438 is 3.3µf50V
C440 is 4.7µf50V
R465 is 100ohm 1/4w

I change those parts and the monitor is working again with no fire anymore.  But, the heat was probably big the first time since some solder were gone on the IC just aside of the burnt parts.

Now the image is present but still horizontally squished a little in the center and fat on the side.  I don't know if the IC is dead, but the image is not good enough to use on a regular basis.

It was fun trying anyway   Thanks for all your help!

Yanick

[PrototypeShogun]

I've got one of these monitors too, they seem to be very sensitive and overall not built to last.

Mine has an unadjustable green tint to it. Which renders it useless because I bought it to use on my graphic design machine...