Rigol DS1102E Boots With No Display - Potentially Faulty LCD? - Page 1
Forum section: electronics / repair

author: EnumC
author_rank: Newbie
timestamp: March 02, 2018, 06:03:12 am
content: Hello everyone!I found an eBay listing* with a very strange issue for a DS1102E oscilloscope. When the scope boots up, Channel 1, Measure, Run.Stop LED all lights up as expected. However, the LCD remains off.I believe it is already out of Rigol's 3-year warranty policy but is it worth a shot opening it up or contact Rigol and eat the repair cost however much it may cost? The LED lighting up may indicate that it still boots but the LCD is faulty?Did Anyone else encounter a similar situation? Any suggestion would be highly appreciated.Link to eBay listing in case anyone would like to give it a go:https://www.ebay.com/itm/292369469651

author: stj
author_rank: Super Contributor
timestamp: March 02, 2018, 07:04:24 pm
content: can you connect over usb/ethernet??

author: EnumC
author_rank: Newbie
timestamp: March 02, 2018, 07:31:07 pm
content: Quote from: stj on March 02, 2018, 07:04:24 pmYes. I believe it works over ethernet/usb.

author: DC1MC
author_rank: Super Contributor
timestamp: March 03, 2018, 07:20:33 am
content: Try to shine a strong flashlight (mobile phone one is good) at ca. 45 degree angle into the LCD, do you see some phantom images ?It could be that the LCD backlight is defective, but the LCD is OK.DC1MC

author: EnumC
author_rank: Newbie
timestamp: March 03, 2018, 07:40:56 am
content: Quote from: DC1MC on March 03, 2018, 07:20:33 amDo you know where I can get replacement backlight in this case? I personally never heard of the backlight dying on one of these models before so I'm at a loss.

author: DC1MC
author_rank: Super Contributor
timestamp: March 03, 2018, 08:05:16 am
content: If the backlight in the LDC is done, then the LCD is done, needs replacement (or you have really mad skillz to replace the dead LED).Most of the time is not the LCD backlight itself, but the driver circuit, usually some kind of anemic transistor with PWM control or even some specialized little overheated chip.Anyways, if it's the LCD driver, this is the easiest to repair, if you've confirmed that the LCD itself is producing images with the flashlight method, just follow the flat ribbon cable thicker traces and identify the driver.If the LCD itself is done, Rigol has replacements available, they've quoted me (in Germany)LCD Display: € 90,- + vat 19% = € 107,10,-If the logic board is done, then you may have a big problem.Best of luck,DC1MCP.S> The LCD backlight defects are not that unusual, if I've had 1EUR for each phone, navigator or LCD TV/Monitor/Tablet with a dead backlight, I could by myself a nice Fluke DMM

author: beenosam
author_rank: Regular Contributor
timestamp: March 03, 2018, 03:27:26 pm
content: Open it up inside and see if anything looks crusty or off inside and check connections too.

author: rhb
author_rank: Super Contributor
timestamp: March 03, 2018, 03:54:57 pm
content: One of the Signal Path repair videos covers replacing a failing HP backlight. It all depends upon the construction and the OP's mechanical skills.I'd start by opening it up and reseating the connectors with a close examination of the ribbon connectors. IIRC they used that for the LCD. I was inside mine the other day. But I was just looking to see if there was any solder flux residue on the boards.There is a service manual with instructions on how to disassemble the unit, so find that and read it first. It is pretty detailed about the disassembly though that's about all they tell you.

author: radistx
author_rank: Newbie
timestamp: March 03, 2018, 08:22:58 pm
content: Hey man isn't it DS1102CA from ebay listing?If so. are you the owner or you are planning to buy it?look at the image it was opened already look for marks and dents on the plastic cover.

author: DC1MC
author_rank: Super Contributor
timestamp: March 03, 2018, 09:06:13 pm
content: You mean this one ?https://www.ebay.com/itm/Rigol-DS1102CA-Digital-Oscilloscopes-100MHz-2GSa-s-2-Channels/292369469651The display issue is the smallest, the main problem is the possible massacre that has been done by repair attempts, and if they've dented the case that is not that difficult to open, either were incompetent or didn't care.Give it a price offer of 100USD and at least you'll get some experience and in the worst case you can recover the money selling parts.Cheers,DC1MC

author: radistx
author_rank: Newbie
timestamp: March 03, 2018, 09:18:41 pm
content: Yes.I offered 100$ but they rejected the offer.You are absolutely right about "repairs" that might have been performed on that unit.

author: DC1MC
author_rank: Super Contributor
timestamp: March 03, 2018, 09:53:17 pm
content: @radistx - The scope was posted by EnumC, if you're not the same person, isn't cool to bid over his scope, he'll get upset.In any case, the seller is an used equipment monger, so if that would have been a simple issue, they would have solved already, IMO the scope, as is, isn't worth more than 100USD, is most likely toast for good.But if you have the money, be patient, really the US compared with EU is like an El Dorado, tons of cool stuff all the time, so I'm pretty sure you'll get something better for the money.Cheers,DC1MC

author: EnumC
author_rank: Newbie
timestamp: March 06, 2018, 07:22:01 pm
content: Quote from: radistx on March 03, 2018, 08:22:58 pmGuess I should have made it clearer in the post. Updated. Also, I msg'd the seller last week and he said: "The screen has a very dim/faint display, it appears to be the backlight and respective driver that is the issue", so I don't know if it'll be worth the trouble at the price he's currently listing it at. I was originally planning to swap the LCD from my 1102E to the CA, but the fault could also be the driver. And as @DC1MC said, it looks like they already had a go with it. If anyone like to try their luck, by all means, go for it as long as you let us know whether you are able to fix it

author: wraper
author_rank: Unknown
timestamp: March 06, 2018, 07:31:28 pm
content: it's barely worth the price even if it was fully working.