Hanns-G HU171D & 171A - Blank (white) screen... both of them.

[EGuevarae]

Well. I received two units of this brand/model. They are exactly the same, exept for the DVI input (one has it, and the other does not). One unit came without the power supply/inverter board. The one I received was full of Lelons (none bulged, and monitor turns on but to a white screen). I connected the PSU to the other monitor and the same. I interchanged LCD panels, ribbon cables, Main boards, and nothing changes. Only a white screen. I ordered one unit from eBay ($25.00) but arrived dead, so no PSU (yet) to test.
But the PSU outputs stable 12v and 5v, and to the inverter, which works great, it pumps 20v. The monitor, as soon as it receives signal, go to a green led, and if disconnected from the PC, goes amber and the backlight shuts off.

I checked (in both panels) the fuse on the 5v line in the panel's input, and traced voltage to several other components, so the voltage is reaching the panel. What do you suggest to try.
I'll post pics as soon as someone tells me from where they are needed.

[Wizard]

Either no LVDS activity between LCD panel and the mainboard (aka dud mainboard), or LCD itself is defective.

Got the scope?

Cheers, Wizard

[EGuevarae]

Originally Posted by Wizard

Either no LVDS activity between LCD panel and the mainboard (aka dud mainboard), or LCD itself is defective.

Got the scope?

Cheers, Wizard

I just can't believe I have two dead VBoards with two dead LCD panels next to a working PSU. It's just too bad luck.

[stroogly]

A lot of the newer chipsets (genesis, for example) require 3.3v, which is usually produced right next to the chip. If this PS is out, that could explain your symptom.

Poke around with your meter and see if you see some biggish caps that don't have any voltage on them.

Also, once in a while the crystals or crystal oscillators overheat and blow out.

A pic of the visdo board would be useful.

[EGuevarae]

here are pics of the two boards I have, and the Caps area of the PSU. They have been replaced by Panas.
Also includes is a picture of the area where the connector from the VBoard is connected in the LCD panel. There is a 5V on all that area, so at least the 5v are reaching the panel. The boards respond to VGA signal (green with signal, amber without it) with both panels. I just used the lamps on one screen to test a 172n I'm working on, so I now have only 1 complete panel.
All the caps in the board that has Analog & DVI input are Lelons.
I will check the boards, as I remember seeing a V regulator that outputs 3.3v there (an APL1084-33 IC) I guess I checked it but there's nothing on my notes, so I'll make sure.

[stroogly]

Is the chip with the sticker on top a Genesis GM5621? Looks like one.

This chip needs 1.8V for the brains. You have that, otherwise your LED would not change color when you give it a signal.

It needs 3.3V for the LVDS part of the chip. If this is out it could explain why you have no video.

If it is in fact a gm5621, this is the whole circuit except for the power supplies!

I work for a Genesis developer. This is a nice chip. Least it is when it's working.

[Wizard]

LVDS is very LOW voltage differntial signal. Swings around .8V or less. The LVDS ICs if there is, uses 1.7 to 1.8V, not 3.3V.

Cheers, Wizard

[EGuevarae]

The boards are live, as they receive 5v from the PSU, and respond to the signal (led goes to green or amber as signal comes and goes).
I checked and there are two ICs that get 5v and pump out 3.30v. Then, there's another one that gets 5v and outputs 1.8v. The board that has DVI & VGA is full of Lelons, and I will change those one by one to see if they are the cuplrits.
Also, as for the Genesis chip, it is not a genesis, it is a Novatek. I'll post the ICs info as I change those Lelons.
And I knew that LVDS stands for that (seen it on SCSI buses as LVD signal, which is the same), but I never thought that I'll seen on monitors/LCDs.

[stroogly]

>>LVDS is very LOW voltage differntial signal. Swings around .8V or less. The LVDS ICs
>>if there is, uses 1.7 to 1.8V, not 3.3V.

Hmmm... That makes sense, so I double checked the datasheet.

The LVDS transceiver and the AD converters run off 3.3V supplies; the DVI transceiver and the core (microprocessor) run off 1.8V supplies.

[EGuevarae]

Here's the IC data:

• The APL1084-33 get s 5v and outputs 3.3v.
• An APL1117/GHC9M18 gets 5v and outputs 1.8v - that must be the LVDS working voltage you were talking about.
• An APL1117/GHC9M33 gets 5v and outputs 3.30v - I don't know why it is here since the 1st IC drops from 5 to 3.3v, but it is there.

I replaced just two 16v 100uf Lelons for two Nichicon VX 16v 100uf, and one Lelon 220uf 10v for a Samxon GR 10v 220uf. Still no go : white screen.
I checked and there are voltages from 5v to 1.15~1.30 going from the VBoard to the LCD Panel. The strange thing is that the two are the same model (well, one has DVI input but apart from that, are equal), and have the same failure. I am as curious as hell, and will get another to see what can I do. I just want to know what is wrong with them. The panels are the 1st suspect, but I guess I need a good panel to test the other stuff.
And the Main chip on the cards is a Novatek
NT68633MEFG-64
0608-FA
N1H9N
Any ideas

[EGuevarae]

Originally Posted by Wizard

Either no LVDS activity between LCD panel and the mainboard (aka dud mainboard), or LCD itself is defective.

Wizard, you were right. I got my hands on a X2Gen MG17S that has the same HannStar 170E13 panel as this two units (the X2Gen has a dead inverter). I ook the screen, assembled the Hanns-G (using the VGA & DVI board) and it is working since 5pm (almost 10 hours ago). oth of my screens are dead, even as they receive the 5v from the VBoard. I fixed une already, and now I have one Hanns-G with a damaged LCD Panel, without lamps (I used them for a Dell E171), and without PSU/Inverter (one of the units came in that way), and an X2Gen without inverter and with a bad panel.I paid $25 for the 2nd unit, to get a PSU. The good thing is that the X2Gen was a gift, but I guess it is too bad luck (or a common failure in that brand/model) that 2 out of 2 had the LCD panel dead ..

[Wizard]

Might have lost one of the voltages on the panel itself. There is a one or two DC-DC converters on the panel circuit board.

Cheers, Wizard

[akmo512]

Im Looking into this white screens problem.

I have notice a High pitch FQ around the inverter half of the power board.

I have about 15 black lines at start then solid white LCD.

I have an acer with the same LCD screen connections , IM GOING TO CHECK SCREEN. I have an idea that the screens intergrated board is faulty.
Will post this weekend hopefully.

I allso have allot of compatible video boards / Power boards
I need the 8-Pin Diagram for the power output - I need the voltage / amps for the inverter and LCD power connections.

If I could get a mutimeter Ide hit'em my self, but Im short one.

SO TO REVIEW CURRENT PROGRESS so far its either the
LCD SCREEN , PCB ,or Video Controller

PS I REPLACED THE RIBBON CABLE
and am going to check screen later

[akmo512]

My theory ,

The power supply goes bad and blows both the video chipset and monitor controller chipset

Every thing I attempted was epic fail , I lost a good monitor in the whole process + screen.

I give up on HANNS G (they make stuff that breaks other stuff )

Stick to power failure and caps and you wont go wrong , do not bother with the white screen its hellish for this series of monitor.

This is the first of 7 monitors I have not repaired / modded
Im not done yet but Caution to any buyer!!!! This is unrepairable

NO DIAGRAMS NO HOPE

[EGuevarae]

Originally Posted by akmo512

... do not bother with the white screen its hellish for this series of monitor. ...

[akmo512]

Ok A few days have passed ,
I have repaired 3 LCDS since and was about to start scraping the caps on the PCB of the HU171D but I thought to give it one more shot

Ive got the screen to work , I was right with going on the acer screen.
I GET A BOX THAT COMFIRMS VIDEO BOARD SEARCHES FOR SIGNAL
then Im getting a ornge flashing light ,
Im going to rebuild it and see what its doing in a min

NOT A VIDEO BOARD PROBLEM
MAYBE A POWER ISSUE I STILL HEAR HIGH FEQ
FOR SURE AN LCD replacement

[akmo512]

I have connected a mag and dell LCD screen in testing purposes.
Both power on FIXED WHITE SCREEN both manifactured by phillips

Problem 2 the cause, the voltage going to the monitor is low and weak
the high pitch squeal is the Power Board and its hardly lighting the tubes
and not holding an operating voltage after the initial power on.Screen loses back light after 2 sec thats if it can muster up the initial ump to light the screen.

My dell lcd attatched to the HANNS flashed white and I figured the Powerboard was trying to kill it.

If I had a voltage tester ide run the whole board
since I dont I might consider a mod, A BALLIST is similar in inital cycle and duty , HAS ANY ONE HAD ANY luck with that idea