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MB6582 LCD is Blank


MyCrazyGarage
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Hello, (and i warn you about my bad english :smile: )

I just got got a new LCD for my MB6582.

The Display is a HD44780 (QC2004A).

 

But sadly it doesent work, its just blank but the backlight is working.

The PICs are from SmasTV , so MIOS is already installed.

I also get the test-tone at start and i can play SID Files, so it should be working.

 

The wiring confused my a bit because the PDF and the board has different numbers at J15:

PDF

1 2

3 4

.....

Board

1 9

2 10

...

But is sems to be correctly wired!

(I already tried the Poti )

I heard i shouldnt connect D0-D3 ?

 

What did i wrong?

A Forum and Google Search brought up many people with the same problem,but it didnt help me.

Edited by MyCrazyGarage
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I checked the wiring. Its all correct (D0-3 removed)

Now i get 5V!

When i activate ..lets say D4 it stays on until i press the next key? thats what i get.

 

Does this mean my new LCD is broken ? Or is there anything else i might have missed?

Edited by MyCrazyGarage
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I did it!!!

It works now. I dont know why but it suddenly started working.

It says "

E002 PInt Ld Chn. 1 

1*** Lead patch"

 

Thanks TK! 

 

 

EDIT: After 10 Minutes it starts to flicker...if i turn the Poti even higer it starts to look good again ..is this bad? (fried ?)

Edited by MyCrazyGarage
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Hi

There are few possibilities to check:

- weak quality pot - change that part 

- bad solder points - resolder again

- invisible shorts - observe pcb

- other e.g. : your lcd likes too much power

 

Cheers

C_04

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Thanks for the answer!.

I powered it up again and there is no more flickering. It was like "the display is burning out and needs more power".

But it sems to be gone now!

PS : NICE it even Displays SIDPlayer Mode and Song Name! (Sadly only sidplayer1 has working MidiOut but plays WAY to fast. )

Im gonna write an update when it fails again.

Edited by MyCrazyGarage
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Once ive  had similar problem - also my lcd was flickering. Reason for that were shorts at lcd connector. You may make a test: measure all points when lcd is working properly and do the same when is flickering. You can also have broken/damaged lcd. But i strongly advice you to check soldering points first.

Cheers

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Double check then lcd interconnections pin to pin especially they not 1:1 compatible <easy way for trouble. When you will be sure tthat here is everything fine check maybe core pcb. Problem may be with PIC socket if you have. If you have possibility check lcd in another device or another lcd with core.  You can use almost anyone 1602, 2002, 4002, 2004 - without uprgrading softare. Just connect - they will only not shows properly if not the same as you had previously. I check lcds that way everytime - connecting them to working device in place of display that this device had/normaly have.

 

P.S. Bad soldering tin often makes bad soldering points;)

Edited by C_04
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Im not sure about 8 bit, there may be necessary to upload new setup with "turned on" that option. Its only my speculation because i never did it in MBSID. So leave it now as is. If you have this second project ready waiting only for lcd then use this one you have - also it will tell you about its condition. 

Once in the past ive read about flickering in 4 bit mode and someone changed it to 8 bit with success. These time intervals: 10 mins.. 20 mins says its probably reason with current flow. Sometime "cold solder points" (as we call them here) produce that interresting visual effects;) Reasons for that are: bad tin, too low temperature of soldering iron, dirty legs/pads etc.

Check all this path around lcd connector points.

Another MBSID functions work properly when display is flickering? Maybe problematic place is a distant place;)

 

Maybe you have inefficient power supply or maybe 7805 is oscillating... many possibilities here. 

Edited by C_04
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Ok I will leave it at 4 Bit.

The Resoldering (might) have done the trick!

Its working since 40 minutes without any sight of flickering (it was more like some pixels were on low voltage).

As far as I can tell does everything work! (Demos ,Keys,Sidplay, Menu ...) 

I havent fully build the Control-Panel....so I had to short the Buttons with a wire.... :rolleyes: .

Thanks for your help!

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If everythings fine now then is great news:)

Anyway just for info: ive bought blue 1602 displays on ebay and they cost me 2$ each with shipping. Unbelivable:) Ive bought 8 of them and i have no idea for what;)

Cheers and youre welcome

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I have the same but negative red < im big fan of reds;). I made special adapter for simpler interconnections if they 1:1. Just what i need is to solder IDC sockets and this adapter itself to lcd. Interconnection are via ribbon cable with squeezed plugs. All job is fast and im 100% sure. Cheers:)

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These blue displays are probably the best visible lcds. But i still prefer red:) Orange are cool too. But the best to me are these VFD used e.g. ENSONIQ TS10/TS12 synths. Unfortunately they only green. Devices with them inside looks stylish and expensive. In one word - great. 

 

I see few of them on my local auction portal but the price... ~29 EUR :(

Edited by C_04
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