First Timer looking for Help! DELL E176FPf

[jimmy2x2x]

Hello, I have been given this Dell E176FPf 17" lcd

It has the classic backlight switches off after a couple of seconds problem.

I have done a visual inspection of the components to the best of my (very limited) ability, and it seemingly looks OK

Where do I start diagnosing this?

I dont have a strong electronics background, but would love to fix this monitor!

Many thanks

[Scenic]

Re: First Timer looking for Help! DELL E176FPf

Su'scon are known crap caps. i'd replace them all (except the 100uF 450V primary filter cap as those rarely fail)

according to this thread (*click*) the caps are most likely gone high-ESR without showing signs of failure, and a resoldering of the board (especially the transformers) could help.

[jimmy2x2x]

Re: First Timer looking for Help! DELL E176FPf

Thanks, what is a good brand to replace the Su'scon caps with?

[Wrog]

Re: First Timer looking for Help! DELL E176FPf

Step 1: Post images using the forum guidelines. Please resize the ones on tinypic.com so they don't mess up the thread width. Nice pics, by the way!

Step 2: Replace all caps except for the fat one on its side (450v one). If you need help picking out replacements, make a list of each cap you want to replace, including make, series, dimensions and values and someone will translate them into a usable list to order. Don't forget to include your location in your profile, so places to buy them can be suggested as well.

After that, troubleshooting steps take different paths and may require some basic equipment (DMM or VOM).

[jimmy2x2x]

Re: First Timer looking for Help! DELL E176FPf

I cant seem to get the resize to stick in tinypc grrrr

Could a mod please edit the OP to include the pics as attached thumbnails pls?

Profile updated to include my locale

01 Su'Scon 220uf 25V SG 105ºC 0538(V)
02 Su'Scon 220uf 25V SG 105ºC 0540(V)
03 Su'Scon 10uf 50V SG 105ºC 0538(V)
04 Su'Scon 470uf 25V SG 105ºC 0540(V)
05 Su'Scon 470uf 25V SG 105ºC 0540(V)
06 Su'Scon 1000uf 25V SG 105ºC 0544(V)
07 Su'Scon 47uf 16V SG 105ºC 0540(V)
08 Su'Scon 680uf 16V SG 105ºC 0539(V)
09 Su'Scon 47uf 16V SG 105ºC 0540(V)
10 Su'Scon 47uf 16V SG 105ºC 0540(V)
11 Su'Scon 47uf 16V SG 105ºC 0541(V)
12 Su'Scon 47uf 16V SG 105ºC 0540(V)
13 Su'Scon 4.7uf 16V SG 105ºC 0540(V) (might 4.7uf be a printing error?)
14 Su'Scon 47uf 16V SG 105ºC 0541(V)
15 Su'Scon 47uf 16V SG 105ºC 0540(V)

Close up of Cap #13


Map

[jimmy2x2x]

Re: First Timer looking for Help! DELL E176FPf

Shopping list format, sorted by uF values

4.7uf 16V SG 105ºC 0540(V)
10uf 50V SG 105ºC 0538(V)
47uf 16V SG 105ºC 0540(V) x5
47uf 16V SG 105ºC 0541(V) x2
220uf 25V SG 105ºC 0538(V)
220uf 25V SG 105ºC 0540(V)
470uf 25V SG 105ºC 0540(V) x2
680uf 16V SG 105ºC 0539(V)
1000uf 25V SG 105ºC 0544(V)

[Wrog]

Re: First Timer looking for Help! DELL E176FPf

Shopping list format, sorted by uF values

4.7uf 16V SG 105ºC 0540(V)
10uf 50V SG 105ºC 0538(V)
47uf 16V SG 105ºC 0540(V) x5
47uf 16V SG 105ºC 0541(V) x2
220uf 25V SG 105ºC 0538(V)
220uf 25V SG 105ºC 0540(V)
470uf 25V SG 105ºC 0540(V) x2
680uf 16V SG 105ºC 0539(V)
1000uf 25V SG 105ºC 0544(V)

Farnell UK has an excellent filtering system for choosing equivalent caps: Farnell UK. Choose the electrolytic types with a cap tolerance of 20%. ESR and lifetime can be left blank to default to all in the category. Be sure to make a note of the dimensions to ensure they will fit (especially the height; check the diameter if its in a crowded area)! One of the favorites that is recommended a lot is the Panasonic FC or FM series.

List of good vendors and series to use as replacements: Recommended cap replacements.

[jimmy2x2x]

Re: First Timer looking for Help! DELL E176FPf

Many thanks, I will get those ordered now

[Wrog]

Re: First Timer looking for Help! DELL E176FPf

Many thanks, I will get those ordered now

I forgot to mention that sometimes you won't be able to get everything in the same vendor and series -- it's OK to mix and match! It's also OK to go up in voltage but never down (for example, substituting a 25V cap for a 16V cap, provided it will still fit).

[EGuevarae]

Re: First Timer looking for Help! DELL E176FPf

I was about to do some suggestions but you seem to have all under control here ...
Only think is I'm more familiar to Panasonic FM or FC....

[Radio Fox]

Re: First Timer looking for Help! DELL E176FPf

Radio Spares (RS) is also a good source for low ESR capacitors in the UK.

As mentioned above, my first choice is Panasonic FM, followed by FC. For some reason RS don't put FM in the title for their FM capacitors, they just call them "Al Electrolytic Cap", but if you click on one of these, the "product overview" or datasheet will show it as FM. http://uk.rs-online.com/web/search/s...uctNum=5261137

Also RS has no minimum order value. Farnell has a minimum order of £20 before VAT and postage. I dont know what Farnell's delivery is like, but RS charge £4.95 (+VAT) & deliver next day, normally by DHL.

[jimmy2x2x]

Re: First Timer looking for Help! DELL E176FPf

OK I have replaced all caps on the board, took my time and did a good job, everything is exactly like it was before - no change at all.

What should I be looking at next?

Thanks

[retiredcaps]

Re: First Timer looking for Help! DELL E176FPf

Check T1 and T2 underside for dry/cold solder joints. If this is a Benq board OEM for Dell, many have suggested this could be an issue.

OK I have replaced all caps on the board, took my time and did a good job, everything is exactly like it was before - no change at all.

What should I be looking at next?

Thanks

[jimmy2x2x]

Re: First Timer looking for Help! DELL E176FPf

I removed all the older solder from the underside of T1 and T2, resoldered - same again.

[PlainBill]

Re: First Timer looking for Help! DELL E176FPf

I removed all the older solder from the underside of T1 and T2, resoldered - same again.

If it isn't obvious, this is a classic example of the 'Two Seconds to Black' problem. Now we have to figure out why the inverter controller is shutting things down.

I have marked up one of the pictures; I would like several more to make the circuitry easier to view.

1. A picture that includes all the area to the left of the black line in the attached picture. Rotate the board so the picture will be in landscape orientation

2. A picture covering the same area, but of the back of the board.

3. If you can do it, pictures of the back side of the board showing only the area around each transformer - the area outlined in orange.

Also, there is probably a 16 pin IC on the back of the board in the inverter area. What is the part number?

PlainBill

[EGuevarae]

Re: First Timer looking for Help! DELL E176FPf

I removed all the older solder from the underside of T1 and T2, resoldered - same again.

Completely unrelated, but do you know that my avatar (Naked Snake/Big Boss), is based on your avatar (Snake Pliskin, from Escape from NY)?

[Solder Boy]

Re: First Timer looking for Help! DELL E176FPf

Took me awhile but I googled those TDK parts.. those are special transformers for the lamps.. looking at your photo each pair of lamp wires is attached to each one, so those may be at fault.

Usually you'll see a pair of 2SC707 ( or similar) transistors in line with the lamps, but not on this monitor.

http://pdf1.alldatasheet.com/datashe...CTSPW-054.html

Hope this helps!