Tektronix THS730A LCD problem - Page 1
Forum section: electronics / repair

author: stfjohn
author_rank: Regular Contributor
timestamp: July 10, 2025, 10:29:08 am
content: Hi everyone. My THS730A is having problems with the LCD screen: a large spot has appeared right in the center of the screen (part number: 119-4985-11). A replacement seems to be nowhere to be found! A friend suggested I try the SHARP LM32P073 as a replacement: can anyone tell me anything about it? Thanks.

author: m k
author_rank: Super Contributor
timestamp: July 10, 2025, 07:23:53 pm
content: Check first that your machine has that 12 pin standard connector.If it has and backlight is also the same the thing turns to a simple mechanical fit or make it fit project.Unfortunately it's not going to be the same with higher resolution panels.

author: Runco990
author_rank: Frequent Contributor
timestamp: July 10, 2025, 08:01:51 pm
content: The screens can be found on ebay. But at the idiotic prices seller want, it can be cheaper to buy an entire scope for parts. The scope can be found cheaper if you look for the 710 or 720. I've bought them for $100.BTW, that "spot" is called vinegar syndrome. Many get it.

author: factory
author_rank: Super Contributor
timestamp: July 12, 2025, 11:10:16 am
content: There are a few mentions of problems with the LCD polarizer failing in the THS7xxx thread, don't know if your screen problems are the same;https://www.eevblog.com/forum/testgear/tek-ths720a-portable-scope-teardowndiscussion/msg3184932/#msg3184932David

author: stfjohn
author_rank: Regular Contributor
timestamp: July 18, 2025, 02:32:29 pm
content: Thanks everyone for your input. I found several deals on Aliexpress for the LM32P10 (the Sharp model used in the THS 730A): do you think it's trustworthy?

author: m k
author_rank: Super Contributor
timestamp: July 20, 2025, 12:57:57 pm
content: I don't use it so can't say.How much is it?ebay has the whole 07 unit as ~50€, no idea how much these can be stripped in general.

author: stfjohn
author_rank: Regular Contributor
timestamp: July 21, 2025, 10:05:49 am
content: Sorry, but where did you see that unit for 50 euros on eBay? I can't find it!

author: m k
author_rank: Super Contributor
timestamp: July 21, 2025, 01:19:05 pm
content: I'm seeing US $59.99 and free shipping.https://www.ebay.com/itm/406014431334And US $62.00 and free shipping.https://www.ebay.com/itm/394513738473Similar adds around both offers.Also same pictures with different prices and not so free shipping.

author: stfjohn
author_rank: Regular Contributor
timestamp: July 21, 2025, 02:53:16 pm
content: Yes, but it is not LM32P10...

author: m k
author_rank: Super Contributor
timestamp: July 22, 2025, 09:44:57 am
content: I didn't say it's 10, I said it's 07, the same you have in your opening post.Don't you accept 07 model anymore, what changed your mind?Generally many panels are electrically the very same.With luck you can strip the actual panel from one frame and fit it to the other.One more meaningful difference can be a refresh rate.Viewing angle and max contrast can be others.Difference between model numbers can be also as mundane as placing of screw holes.Not so mundane if you're not prepared.

author: stfjohn
author_rank: Regular Contributor
timestamp: September 18, 2025, 11:02:37 am
content: I bought the LM32P10 screen from Aliexpress (SHOP1100287357Store) for €138. It arrived in perfect condition (new). If anyone is interested, the seller in question is reliable.

author: RichardM
author_rank: Frequent Contributor
timestamp: September 18, 2025, 02:26:54 pm
content: ThanksI am interested in knowing how it goes and how the new screen looks.Cheers

author: stfjohn
author_rank: Regular Contributor
timestamp: September 18, 2025, 10:03:53 pm
content: I had to adapt the lamp connection cables, because they were too short on the model that arrived (actually, they were original, because the oscilloscope ones had been adapted by Tektronix). The screen looks perfect.

author: m k
author_rank: Super Contributor
timestamp: September 19, 2025, 06:16:51 am
content: Was it otherwise a drop in replacement?Type markings after P10 can be also used for different mechanical settings.

author: RichardM
author_rank: Frequent Contributor
timestamp: September 20, 2025, 10:24:12 am
content: I would love to see a couple of pics of the screen. I am contemplating buying one. Cheers

author: stfjohn
author_rank: Regular Contributor
timestamp: September 20, 2025, 12:45:28 pm
content: Photos.

author: RichardM
author_rank: Frequent Contributor
timestamp: September 20, 2025, 01:29:18 pm
content: ThanksAt looks really good 👍

author: stfjohn
author_rank: Regular Contributor
timestamp: September 20, 2025, 02:09:58 pm
content: Sorry Mark, I didn't understand the meaning of your last post...

author: m k
author_rank: Super Contributor
timestamp: September 21, 2025, 07:30:07 pm
content: Did you have to modify it in any other way than lengthening the backlight wire?Like shaping some plastic or metal surroundings.What is its exact type?If it's not same as the original.

author: stfjohn
author_rank: Regular Contributor
timestamp: September 22, 2025, 10:47:08 am
content: I just had to extend the backlight lamp connection cables. The original model installed on the THS730A is the Sharp LM32P10. Sharp likely had them made in China (the model that arrived, absolutely new and identical to the original, marked LM32P10, appears to be produced in China and the seller appears to have a considerable quantity of them on hand!).

author: rvalente
author_rank: Frequent Contributor
timestamp: September 23, 2025, 01:30:10 pm
content: Would you know if there is there a LED LM32P10 compatible module, without using retrofit kits?

author: stfjohn
author_rank: Regular Contributor
timestamp: September 23, 2025, 02:48:22 pm
content: No, sorry. But I think someone on this forum has managed to do it. Try typing Tektronix THS....

author: TERRA Operative
author_rank: Super Contributor
timestamp: September 23, 2025, 04:44:20 pm
content: There are a couple of us (including me) that have made an LED backlight replacement.It replaces the original CCFL inverter with a drop-in replacement, and you install a thin LED strip into the LCD in place of the CCFL tube. It's not too difficult, you just need to be careful not to break the delicate plastic bits.I'll be revisiting my design soon-ish as I'm not 100% happy with it. Once I have time after finishing the design of my TDS500/600/700 series scope LCD conversion.

author: RichardM
author_rank: Frequent Contributor
timestamp: September 25, 2025, 02:39:16 am
content: I was just about to do this mod myself. What exactly are you not happy about with the backlight pcb on Pcbway ? I note the link to your version is no longer shared?I went to all the trouble of scraping off the polariser glue only to glue the new ones on the wrong way….. I have a black background with white text. What a fool. 😬Does anybody know why the Harmonics option is limited to 400hz? I was hoping to use this for audio work only to find this limitation out after.Richard

author: Labrat101
author_rank: Unknown
timestamp: October 04, 2025, 09:28:13 pm
content: Hi I also have a problem with my THS720A screen . I managed to replace the polarizers front and back worked great for a few weeks .and now the screen has developed 1 line horizontal and 3 vertical bad lines . not a happy camper .Ordered a new screen on Ali-express the seller said it was a 100% compatible . $120 plus got done by customs for another $40 .Guess What it didn't work . Yup returned to Ali got most of my money back . still lost the customs money .So I'm still looking for a 100% compatible LM32P10 .Is there a way to make a converter .this screen as far as I can see is parallel 4bit and the THS720a M/B checks the clock & code .There must be an easier solution . I know that most of the clone LM32p10 Don't work .

author: Labrat101
author_rank: Unknown
timestamp: October 04, 2025, 09:55:12 pm
content: Hi I looked for that seller wasn't sure its the same .but as you said its good . did it come with a small connector PCB to correct and connect the ribbons ?.Is the screen slightly smaller ?Please could you give the full link . Pleaseas SHOP1100287357Store search comes up with another supplier not sure if its the same as yoursThanks

author: stfjohn
author_rank: Regular Contributor
timestamp: October 09, 2025, 11:09:22 am
content: The screen I received is identical to the original one mounted on the THS730A (same dimensions). The connecting cables have a small connector, but they are short. I used the cable originally mounted on the Tektronix, cutting the existing ones on the screen I received (Tektronix had done the same thing!). The seller's link is the one I provided: I tried searching for it on Aliexpress, but, in truth, it seems like an impossible task. I suggest you search for the LM32P10 screen until you find the supplier in question...

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 09, 2025, 12:23:11 pm
content: I just bought this one and installed it last night, it works perfectly.Check the reviews for a picture.www.aliexpress.com/item/1005008953075687.html

author: Labrat101
author_rank: Unknown
timestamp: October 14, 2025, 03:32:02 pm
content: For anyone interested LM32p10 and the LM32k101 are mechanical the same only difference is the polarized screen colorP is blue were the K is silvered so it is visible in sunlight and can be seen without the back light .There are 3 mentioned in the sharp manual Lm320 x10 all QVGA parrell 4bit.Enjoy.Ps on the pcb board check the numbersN1250cp-1 if the number isn't present on board its a clone .