Author Topic: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)  (Read 15989 times)

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Online KungFuJosh

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #125 on: August 28, 2024, 04:50:40 am »
R5 at 5.1k is definitely better.

Now I should go to bed 2 hours ago. 😬

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Offline coromonadalix

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #126 on: August 28, 2024, 05:30:20 am »
the best results so far
 
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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #127 on: August 28, 2024, 05:40:27 am »
You almost need a breakout board like a mini 'mixing desk' of trimpots to tweak and dial them in to get it perfect, then substitute with the closest fixed values. :-DD
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Offline coromonadalix

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #128 on: August 28, 2024, 12:52:08 pm »
loll yep  had the same toughts ....   but i would say somewhat usable like this ...  depends of the OP  loll

seems a bit weak in the lower corners ?

@KungFu   can you show us the  chip markings for the row and column drivers ?  u9 u10 u11 too ?
« Last Edit: August 28, 2024, 01:10:45 pm by coromonadalix »
 
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Online KungFuJosh

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #129 on: August 28, 2024, 02:09:43 pm »
loll yep  had the same toughts ....   but i would say somewhat usable like this ...  depends of the OP  loll

seems a bit weak in the lower corners ?

@KungFu   can you show us the  chip markings for the row and column drivers ?  u9 u10 u11 too ?

A pot doesn't work in every position. R1 was okay, R6 did nothing, and I think R5 hated not being a fixed value for some reason. 🤷

I definitely think it's easily usable now, but I might try 5.6k in R5 as R5 seems to directly affect those corners. My only concern is that it might cause some more ghosting. I also think it looks better in person than in the photos.

In reply #110 above, there's a high resolution attachment you should be able to view the chip markings on (the one with the -min suffix).

Thanks,
Josh
« Last Edit: August 28, 2024, 02:40:59 pm by KungFuJosh »
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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #130 on: August 28, 2024, 03:07:06 pm »
Here's a real photo with R5 increased to 5.6k. Contrast is at max but stuff still looks like crap, and now I would need to adjust R2 to shift things over and continue chasing the perfect balances. 🙄
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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #131 on: August 28, 2024, 04:56:38 pm »
On a side note, the resistor book I got is bullshit. Supposed to be 1%, but I don't have any 1k resistors because they're all 1.2k marked 1001. 🙄
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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #132 on: August 28, 2024, 06:41:47 pm »
After further experimenting, I went back to:
R1 1.2k
R2 7.5k
R3 82k
R4 4.7k
R5 5.1k
R6 8.2k

There's some very minor ghosting, but overall I think it looks great.

Here's the thing though. I originally was going to keep this, but now that I have an IM3570, I no longer need it, and I don't have the space for both anyway.

I have another touch panel on the way, and if it works, I'm going to sell this. So the question is, hypothetically, would you buy this LCR with how the screen looks in this photo? Or should I scrap it and try and get an original replacement LCD instead?



If the new touch panel doesn't work, I'll probably sell it for parts/repair, as I'm spending too much time on this, even if it was entertaining. Somebody with better skills & more ambition can try and improve it further if they want. 😉

Thanks,
Josh
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Online Martin72Topic starter

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #133 on: August 28, 2024, 09:34:50 pm »
I would stop worrying about the little bit of ghosting and concentrate fully on the touch panel.
As far as I can see, the ghosting is far removed from the 4 displayable parameters.
I still find it fascinating that the display didn't work the way you'd want it to right away, especially since it's explicitly offered as a replacement.
I also don't believe that the supplier doesn't have a circuit diagram for it, if he can give recommendations for resistor assemblies in the same breath.
That's typically Chinese: they copy themselves like world champions, but don't give anything away in return.
 
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Online KungFuJosh

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #134 on: August 28, 2024, 10:02:28 pm »
I would stop worrying about the little bit of ghosting and concentrate fully on the touch panel.
As far as I can see, the ghosting is far removed from the 4 displayable parameters.
I agree, I think I'm over the minor ghosting. I looked at the stock panel again, and it has a giant rectangle behind the entire display, and the contrast only looks darker because it's not backlit. If you zoom in you can still see the pixelation, and some thin vertical line gaps. I think the illumination shining a light on that stuff made it stand out more.

I still find it fascinating that the display didn't work the way you'd want it to right away, especially since it's explicitly offered as a replacement.
I also don't believe that the supplier doesn't have a circuit diagram for it, if he can give recommendations for resistor assemblies in the same breath.
That's typically Chinese: they copy themselves like world champions, but don't give anything away in return.

It isn't offered as a replacement. The seller suggested this LCD as a replacement based off the dimensions and the generic model number of the stock panel. It's not advertised as being specifically used with the Hioki.

I also don't know how much they know about it. My guess is that they may have purchased the design files and manufactured based on that rather than having anything to do with the design of the product. They showed me a screenshot that clearly came from PCB design software, but they didn't seem to, or at least didn't admit to, understanding what the resistors do better than I understand now...and my understanding is still limited.

I did a reverse google image search of the back of the LCD, and the panel came up with a few different model numbers, but clearly the same panel. Most of them were more expensive too. Still no datasheets for any of them.

ETA: The ETA of the new touch panel is Mon or Tuesday next week. I hope it's a good one!
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Online Martin72Topic starter

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #135 on: August 28, 2024, 10:12:06 pm »
Quote
It isn't offered as a replacement. The seller suggested this LCD as a replacement based off the dimensions and the generic model number of the stock panel. It's not advertised as being specifically used with the Hioki.

 ;)

What was it advertised as, how did you find out about it?
Plus:
Powertip did not explicitly advertise the PG320240 as a display for the Hioki only.
Hioki only used it for its own purposes without changing anything.

Online KungFuJosh

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #136 on: August 28, 2024, 10:28:37 pm »
What was it advertised as, how did you find out about it?
Plus:
Powertip did not explicitly advertise the PG320240 as a display for the Hioki only.
Hioki only used it for its own purposes without changing anything.

I googled the part numbers, and similar stuff came up. Then I messaged the seller to see whether the LCD I found was compatible or not. It wasn't, so he suggested this one instead.

I couldn't tell you for sure why any of it is the way it is. Do we know for sure that Hioki didn't have Powertip customize any parts of the panels?

ETA: I should add, I think the sellers level of understanding when suggesting the replacement was based on the physical measurements more than anything else. 😉
« Last Edit: August 28, 2024, 10:37:02 pm by KungFuJosh »
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Online Martin72Topic starter

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #137 on: August 28, 2024, 10:35:49 pm »
Quote
Do we know for sure that Hioki didn't have Powertip customize any parts of the panels?

I would almost blindly say that this is not the case, because what is the current problem?
The contrast, or....
And that is a matter for the display.

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #138 on: August 28, 2024, 10:38:55 pm »
It's not just contrast. It's:
all theses resistors things must play with duty cycle, timings  etc ...   it's a matter of finding the row and column drivers data sheet if they exists and try to figure out   ...

Anyway, it's in a pretty good place now. Easy to read and stable.
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Online Martin72Topic starter

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #139 on: August 28, 2024, 10:53:22 pm »
Quote
It's not just contrast. It's:

If we had a circuit diagram, we would really know.
That is one point.
The other is that, in contrast to today's displays, they were still rather “raw” over 20 years ago.
The graphics/character generation was on board, in this case 4 bits were “pushed over” to the display in parallel.

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #140 on: August 28, 2024, 11:18:59 pm »
Sure, but the new LCD didn't exist 20 years ago, and I assume was built with expectations of newer applications. So maybe that's where the need for changes comes from. I dunno, we'll likely never see a real circuit diagram anyway. 🤷
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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #141 on: August 28, 2024, 11:24:33 pm »
Quote
Sure, but the new LCD didn't exist 20 years ago, and I assume was built with expectations of newer applications.

The data stream from the controller to the “raw” display has nothing to do with the display quality, neither 20 years ago nor now.
The only thing that might have changed is the TTL level, from the former 5V to 3.3V.
I'll figure it out, I'm afraid.... ;)

Good night.
« Last Edit: August 29, 2024, 05:50:57 am by Martin72 »
 

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #142 on: August 28, 2024, 11:27:20 pm »
I'll figure it out, I'm afraid.... ;)

I look forward to your findings. 😉

Gute nacht.
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Offline coromonadalix

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #143 on: August 28, 2024, 11:31:53 pm »
this is the main drivers ic's,   check on the page 8, 10, 11   and note 2 ...
 
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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #144 on: August 28, 2024, 11:42:32 pm »
Thank you, but I don't know how to make any sense of that without a schematic. Even still, it might be above my paygrade. 😉

R1 - R6 are all mostly interacting with the LM324 chip, and then some tantalum capacitors. What happens after that, I dunno.
« Last Edit: August 29, 2024, 03:19:40 am by KungFuJosh »
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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #145 on: August 29, 2024, 01:14:33 am »
Take a look at pages 8, 11 and 30 of the datasheet coromonadalix posted, it might help get you started.
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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #146 on: August 29, 2024, 01:37:49 am »
I did, but...

Even still, it might be above my paygrade. 😉

Looking at those charts doesn't tell me any specific details about what component/value I would need to change to reduce the minor ghosting present. 🤷
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Offline coromonadalix

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #147 on: August 29, 2024, 01:44:23 am »
some notes on p15 p16

3. V0, V12, V43, V5 pin
4. VLCD = VDD - VEE, V0 = VDD = 5V, V5= VEE = -23 V
V12 = VDD-2/n(VLCD), V43 = VEE+2/n(VLCD), n = 17 (1/256 duty, 1/17 bias)
5. V0 = VDD, V12 = 1.71V(VDD = 5V) or -0.06V (VDD = 3V),
V43 = -19.71 V(VDD = 5V) or -19.94V (VDD = 3V), V5 = VEE = -23V, no-load condition (1/256 duty, 1/17 bias)

i never saw an lcd with the same ic's for column and row,     for sure   the voltage thing is something .....  scratching my head
and the missing 8 pins soic, some of them or one of them would-could be a negative supply generator (i think) not installed

maybe theses calculation may help to fine tune the resistors ? and the lm324  could act as buffer(s) something since it's a quad op amp
« Last Edit: August 29, 2024, 10:04:48 am by coromonadalix »
 
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Online KungFuJosh

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #148 on: August 29, 2024, 01:53:13 am »
U8 is "negative pressure" according to the seller, and it's currently installed. The seller told me to try it again. It didn't affect the ghosting, but maybe made the flicker worse. That is to say, the flicker wasn't noticeable with my other values, but now there's a hint of it with U8 installed.

ETA: I reduced R4 to 3.9k and the flicker is gone with U8 installed.
« Last Edit: August 29, 2024, 02:57:13 am by KungFuJosh »
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Offline coromonadalix

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Re: Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted)
« Reply #149 on: August 29, 2024, 10:24:28 am »
maybe  in all of this  it's a matter of getting the multiples voltages and get the right duty cycles ...     you have to check your older lcd to see at what it was, and fit the new as such

could be some timing issues at some point for the ghosting when it happens

the Hioki must use strict settings, and most of the glcd 320x240 could be out of it, there is so many on the market, so many ic's  etc ...   

to fit with the motherboard SED1335F driver, it work at 1/2-duty to 1/256-duty LCD drive

maybe at some point, you may have to live with it  like this ???

your original Powertip can be found (post #14),  but some say compatible on ebay, but over 75$  is a huge rip off
 
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