HP L1706 black screen, powers 'on'

[bfordz]

I have a HP L1706 flat screen monitor that powers "on" but has a black screen.

If I shine a flashlight from an angle I can see what's supposed to be lit up or displayed on the screen.

I pulled the AIO board and it has several bad caps, so I want to replace them but I could use some advise as to what to replace them with.

Here's what is currently on the board (referenced in my pic also)
They're all Su'scon caps
#1 25v 470uF 105° x 5 (3 bulging)
#2 50v 470uF 105° x1
#3 16v 680uF 105° x1
#4 16v 47uF 105° x7
#5 16v 4.7uF 105° x3
#6 50v 10uF 105° x2
#7 450v 100uf 105° x1

Question on finding replacements;
besides V, uF, temp, and physical size what other spec's are important when finding a replacement cap?
I'm not an electronics guru so some of the other spec's is where I get lost or confused when they don't 'match' the original cap.
eg.; ripple current, impedance and the different series within manufacturer.

[bfordz]

Re: HP L1706 black screen, powers 'on'

I did some looking and for the first 3 set of caps this is what I'm thinking:

#1 25v 470uF 105° x 5 (3 bulging)
-- replace with Rubycon 25ZLH470MEFC10X12.5

#2 50v 470uF 105° x1
-- replace with Rubycon 50ZLH470MEFC12.5X20

#3 16v 680uF 105° x1
-- replace with Rubycon 16ZLH680MEFC10X12.5

For the smaller caps, I'm having trouble finding Su'scon spec's to match up a good brand cap to.

** I forgot to mention the Su'scon caps are SG series **

[Andrew F. Ali]

Re: HP L1706 black screen, powers 'on'

Good job at re-capping your PSU but you should check those blue HV caps around the backlight transformer and the PWM IC to driver this transformer. Perhaps too the CCFLs are defective??

[bfordz]

Re: HP L1706 black screen, powers 'on'

Andrew,
Thanks for the heads up and advise.
I'll keep that in mind if these don't fix my problem.

[bfordz]

Re: HP L1706 black screen, powers 'on'

I replaced the first 3 set of caps; 25v-470uF, 50v-470uF and 16v-680uF, my (original) monitor is back up and working.

Now I have a 2nd Identical monitor with the same exact problem with the same psu board and Su'scon bad caps.

I still want to find replacements for second 3 set of caps I have listed above even though I still haven't been able to find Su'scon specs for those.
This is what I'm thinking for replacements:

Su'scon 16v-47uF replace with Nichicon UPW1C470MDD 16v-47uF 5mm x 11mm
Su'scon 16v-4.7uF replace with Nichicon UPW1E4R7MDD 25v-4.7uF 5mm x 11mm ** 16v not available
Su'scon 50v-10uF replace with Nichicon UPW1H100MDD 50v-10uF 5mm x 11mm

basically I'm going with the same v, uF and / or physical size without having any Su'scon spec's.

any opinions on those thoughts?
first time I'm replacing caps without a direct comparison spec's.

[momaka]

Re: HP L1706 black screen, powers 'on'

Nichicon PW/UPW should be fine for the above 3 caps, and a good choice in general for power supplies. Same goes for Nichicon PS, PM, PJ, HE, and HW. If going with other brands, you can use any of the following in hot and/or stressful PSUs:
Chemicon KY, KYB, KZE,
Rubycon YXJ, YXG, ZL, ZLH
Panasonic FC, FR, FM, FS, FK
Probably a few more series I missed in the above list as well, but these generally are fine for power supplies. When it comes to PSU recapping, I now always try to match my new caps the caps reasonably close to the originals (within 20-30% tolerance). But when I can't find a datasheet and I'm recapping a power supply, the brands/series in the above list is a pretty safe bet.

[bfordz]

Re: HP L1706 black screen, powers 'on'

momaka,

Thanks for that information. I'll keep that for reference.
I've been bit by the re-cap'n bug. IF it breaks I just gotta look inside!

Since this HP monitor, I've got a Dell projector dead and an APC UPS overload