Hanns-g HG281DJ stuck on self test after changing caps

[budm]

Re: Hanns-g HG281DJ stuck on self test after changing caps

You are right, it is fixed now, thanks for pointing out.
It is nice of them to print the voltages on the board.

[selldoor]

Re: Hanns-g HG281DJ stuck on self test after changing caps

Here is my caps shopping list (main board only)

12 of 10uf 25v 4x7mm 105c
5 of 100uf 16v 5x11 105c
3 of 470uf 16v 8x11.5 105c

When I search for these on the Farnell site I get up to 10 to choose from.
Can somebody recommend the best ones to go for out of the 3 caps?

470uf

100uf

10uf

Also, do you think their cheapest desoldering gun would do the trick?
I don't intend trying to impress the ladies with my desoldering gun so the size/quality isn't important to me (I'm also skint).

Recommended braid?
I only intend buying what I might need for this job only.

A lot of this is down to personal preference many members use and recommend Panasonic FR.
For the smaller caps either the rubicon or panasonic will do - id stick with panasonic - Nichicon are US stock so incur a £15 excess charge.

Braid- I like 2mm, others swear by 1mm - If I need it thinner I just cut it to a point- (careful in case any bits are loose)

Solder sucker - personally I dont use one- for this work I think the braid will suffice.


http://uk.farnell.com/exar/spx1117m3...223/dp/1831942

http://uk.farnell.com/edsyn/sw021-2-...mx1/dp/1182013

http://uk.farnell.com/panasonic/eeuf...0uf/dp/1800634

http://uk.farnell.com/panasonic/eeuf...0uf/dp/1907228
http://uk.farnell.com/panasonic/eeag...7mm/dp/2079087

EDIT

Just before you order have you tried the hairdrier trick.
You set it all up and warm the boards (gently) with a hair drier.

If the set is slow to come on you use it to see if warming it makes it come on sooner.
If the set switches off after a while you use it to see if it makes it go off quicker.

It is sometimes possible to pinpoint a component that is causing the problem.

[waigy]

Re: Hanns-g HG281DJ stuck on self test after changing caps

Thanks for the replies

Just before you order have you tried the hairdrier trick.

My problem when I started this post was no longer the monitor taking a while to start up.
It was the fact that it only shows solid colours on screen (self test).
This problem started after I tried to change caps c80 and 83.

That's why I started a new thread instead of posting in the mega thread which is mostly about the heating/starting problem.
I also don't have a hair dryer, just a fan heater, but when I did have the warm up problem, using the fan heater did make it start quicker.

I'm ordering the parts now and have found out about the £20 minimum order.

I'm having to buy stuff I don't need to make up the price.
What temperature tip would you recommend for doing this job on my weller ps-2d with tcp-fe iron?
370c 425c or 480c?

[waigy]

Re: Hanns-g HG281DJ stuck on self test after changing caps

I'm waiting till somebody can recommend a good iron tip before I order my parts.

Here's all the options I have for my weller tcp fe iron.
http://www.farnell.com/datasheets/19757.pdf

Can someone recommend the best size, shape and temperature tip for this job?

[selldoor]

Re: Hanns-g HG281DJ stuck on self test after changing caps

Iron Tips - again its personal choice - I prefer a round chisel tip. As a beginner it may not make much difference what makes the difference is practice. One thing I have found is that pre warming the whole board helps. and when de soldering add a bit of new solder and flux, seems to help it melt.

Supplies - Farnell - their subsidiary CPC and RS electronic components are the main ones, Maplins do not stock many suitable capacitors, if any!. You can check locally sometimes there are odd repair outlets that sell caps- whilst at a premium it is still cheaper than Min order fee plus Min order postage.
There is also digikey and Mouser.
Mouser doesnt seem to have a minimum order or small order fee but delivery may be £12.-Perhaps give them a ring and ask?

RS have a trade counter in Glasgow and Aberdeen but I guess
you will be in the middle and too far from either?

[waigy]

Re: Hanns-g HG281DJ stuck on self test after changing caps

I just finished re capping the main board and I'm still just getting a self test.
If anything is connected by hdmi (pc or video camera) the blue led stays on and it goes through solid colours forever.
If I disconnect the hdmi it goes onto stanby orange led.

I was dreading doing the job myself, but I ended up doing a pretty good job of it after I got some solder wick and a smaller tip for my weller.
All rubycon caps except the 470s which are Panasonic.

Going back to the symptoms, it was working fine before I tried to change C80 and C83 last week, it was just taking a while to warm up.

So I have only worked on the main board, I've done nothing to the power board or inverter board.

Although I did a good job of the recap, I didn't do a good job last week, so there's a chance I could have heat damaged some of the tiny components near C80 and C83.

I fitted a new voltage regulator in U8 which is now reading :
0.03
1.80
3.27

What is my next step?

[waigy]

Re: Hanns-g HG281DJ stuck on self test after changing caps

I've fixed it!

Just out of curiosity I had a look under the black tape that covers the end of the cable that goes from the main board to the LCD screen.

I noticed that the connector (arrowed) was half pulled out, shoved it in and it works.
I had to disconnect the other end of that cable a few times to access the main board so I must have pulled it out last week after my first attempt at changing two caps.

Now I have a tuned up Hanns-g with Rubycon and Panasonic caps and more importantly, I know that I'm a solder master after changing 20 caps and a VR.

Thanks for the help people, especially selldoor.

[selldoor]

Re: Hanns-g HG281DJ stuck on self test after changing caps

Firstly - well done!!

Secondly -Damn!! cant understand how I missed that- In the last week I have told at least two others to check that exact connector -even explained that it often gets moved during re assembly. Concentrated too much on the main board and missed the bigger picture - haha. ( Not used that before)